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Bagwell JW, Subedi M, Sapkota S, Lopez B, Ghimire B, Chen Z, Buntin GD, Bahri BA, Mergoum M. Quantitative Trait Locus Analysis of Hessian Fly Resistance in Soft Red Winter Wheat. Genes (Basel) 2023; 14:1812. [PMID: 37761952 PMCID: PMC10531203 DOI: 10.3390/genes14091812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 09/10/2023] [Accepted: 09/14/2023] [Indexed: 09/29/2023] Open
Abstract
The Hessian fly (HF) is an invasive insect that has caused millions of dollars in yield losses to southeastern US wheat farms. Genetic resistance is the most sustainable solution to control HF. However, emerging biotypes are quickly overcoming resistance genes in the southeast; therefore, identifying novel sources of resistance is critical. The resistant line "UGA 111729" and susceptible variety "AGS 2038" were crossbred to generate a population of 225 recombinant inbred lines. This population was phenotyped in the growth chamber (GC) during 2019 and 2021 and in field (F) trials in Georgia during the 2021-2022 growing seasons. Visual scoring was utilized in GC studies. The percentage of infested tillers and number of pupae/larvae per tiller, and infested tiller per sample were measured in studies from 2021 to 2022. Averaging across all traits, a major QTL on chromosome 3D explained 42.27% (GC) and 10.43% (F) phenotypic variance within 9.86 centimorgans (cM). SNP marker IWB65911 was associated with the quantitative trait locus (QTL) peak with logarithm of odds (LOD) values of 14.98 (F) and 62.22 (GC). IWB65911 colocalized with resistance gene H32. KASP marker validation verified that UGA 111729 and KS89WGRC06 express H32. IWB65911 may be used for marker-assisted selection.
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Affiliation(s)
- John W. Bagwell
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (J.W.B.); (M.S.); (B.G.); (B.A.B.)
| | - Madhav Subedi
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (J.W.B.); (M.S.); (B.G.); (B.A.B.)
| | - Suraj Sapkota
- Small Grains and Potato Germplasm Research Unit, United States Department of Agriculture Agricultural Research Service, Aberdeen, ID 83210, USA;
| | - Benjamin Lopez
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (B.L.); (Z.C.)
| | - Bikash Ghimire
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (J.W.B.); (M.S.); (B.G.); (B.A.B.)
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA 30223, USA
| | - Zhenbang Chen
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (B.L.); (Z.C.)
| | - G. David Buntin
- Department of Entomology, University of Georgia, Griffin Campus, Griffin, GA 30223, USA;
| | - Bochra A. Bahri
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (J.W.B.); (M.S.); (B.G.); (B.A.B.)
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA 30223, USA
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (J.W.B.); (M.S.); (B.G.); (B.A.B.)
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA 30223, USA; (B.L.); (Z.C.)
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Bahri BA, Parvathaneni RK, Spratling WT, Saxena H, Sapkota S, Raymer PL, Martinez-Espinoza AD. Whole genome sequencing of Clarireedia aff. paspali reveals potential pathogenesis factors in Clarireedia species, causal agents of dollar spot in turfgrass. Front Genet 2023; 13:1033437. [PMID: 36685867 PMCID: PMC9849252 DOI: 10.3389/fgene.2022.1033437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/21/2022] [Indexed: 01/06/2023] Open
Abstract
Dollar spot is one of the most damaging diseases in turfgrass, reducing its quality and playability. Two species, Clarireedia monteithiana and C. jacksonii (formerly Sclerotinia homoeocarpa) have been reported so far in the United States To study the Clarireedia genome, two isolates H2 and H3, sampled from seashore paspalum in Hawaii in 2019 were sequenced via Illumina paired-end sequencing by synthesis technology and PacBio SMRT sequencing. Both isolates were identified as C. aff. paspali, a novel species in the United States Using short and long reads, C. aff. paspali H3 contained 193 contigs with 48.6 Mbp and presented the most completed assembly and annotation among Clarireedia species. Out of the 13,428 protein models from AUGUSTUS, 349 cytoplasmic effectors and 13 apoplastic effectors were identified by EffectorP. To further decipher Clarireedia pathogenicity, C. aff. paspali genomes (H2 and H3), as well as available C. jacksonii (LWC-10 and HRI11), C. monteithiana (DRR09 and RB-19) genomes were screened for fifty-four pathogenesis determinants, previously identified in S. sclerotiorum. Seventeen orthologs of pathogenicity genes have been identified in Clarireedia species involved in oxalic acid production (pac1, nox1), mitogen-activated protein kinase cascade (pka1, smk3, ste12), appressorium formation (caf1, pks13, ams2, rgb1, rhs1) and glycolytic pathway (gpd). Within these genes, 366 species-specific SNPs were recorded between Clarireedia species; twenty-eight were non-synonymous and non-conservative. The predicted protein structure of six of these genes showed superimposition of the models among Clarireedia spp. The genomic variations revealed here could potentially lead to differences in pathogenesis and other physiological functions among Clarireedia species.
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Affiliation(s)
- Bochra Amina Bahri
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States,Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin, GA, United States,*Correspondence: Bochra Amina Bahri,
| | - Rajiv Krishna Parvathaneni
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States,Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin, GA, United States
| | | | - Harshita Saxena
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin, GA, United States
| | - Suraj Sapkota
- Department of Plant Pathology, University of Georgia, Griffin, GA, United States
| | - Paul L. Raymer
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Griffin, GA, United States,Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, United States
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Ghimire B, Mergoum M, Martinez-Espinoza AD, Sapkota S, Pradhan S, Babar MA, Bai G, Dong Y, Buck JW. Genetics of Fusarium head blight resistance in soft red winter wheat using a genome-wide association study. Plant Genome 2022; 15:e20222. [PMID: 35633121 DOI: 10.1002/tpg2.20222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 04/10/2022] [Indexed: 06/15/2023]
Abstract
Host resistance is an effective and sustainable approach to manage the negative impact of Fusarium head blight (FHB) on wheat (Triticum aestivum L.) grain yield and quality. The objective of this study was to characterize the phenotypic responses and identify quantitative trait loci (QTL) conditioning different FHB resistance types using a panel of 236 elite soft red winter wheat (SRWW) lines in a genome-wide association study (GWAS). The panel was phenotyped for five FHB and three morphological traits under two field and two greenhouse environments in 2018-2019 and 2019-2020. We identified 160 significant marker-trait associations (MTAs) for FHB traits and 11 MTAs for plant height. Eleven QTL showed major effects and explained >10% phenotypic variation (PV) for FHB resistance. Among these major loci, three QTL were stable and five QTL exhibited a pleiotropic effect. The QTL QFhb-3BL, QFhb-5AS, QFhb-5BL, QFhb-7AS.1, QFhb-7AS.2, and QFhb-7BS are presumed to be novel. Pyramiding multiple resistance alleles from all the major-effect QTL resulted in a significant reduction in FHB incidence, severity, index, deoxynivalenol (DON), and Fusarium-damaged kernel (FDK) by 17, 43, 45, 55, and 25%, respectively. Further validation of these QTL could potentially facilitate successful introgression of these resistance loci in new cultivars for improved FHB resistance in breeding programs.
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Affiliation(s)
- Bikash Ghimire
- Dep. of Plant Pathology, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics, and Genomics, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223, USA
- Dep. of Crop and Soil Sciences, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | | | - Suraj Sapkota
- USDA-ARS, Crop Genetics and Breeding Research Unit, Tifton, GA, 31794, USA
| | - Sumit Pradhan
- Dep. of Agronomy, Univ. of Florida, Gainesville, FL, 32611, USA
| | - Md Ali Babar
- Dep. of Agronomy, Univ. of Florida, Gainesville, FL, 32611, USA
| | - Guihua Bai
- USDA-ARS, Hard Winter Wheat Genetics Research Unit, Manhattan, KS, 66506, USA
| | - Yanhong Dong
- Dep. of Plant Pathology, Univ. of Minnesota, St. Paul, MN, 55108, USA
| | - James W Buck
- Dep. of Plant Pathology, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223, USA
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Sapkota S, Molitor J, Evans M, Kofoed B, Lord A, Robinson L, Crosson J. AB1384 CLINICAL SIGNIFICANCE OF DENSE FINE SPECKLED PATTERN ANA. Ann Rheum Dis 2022. [DOI: 10.1136/annrheumdis-2022-eular.5294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BackgroundThe clinical significance of Dense Fine Speckled (DFS) pattern Anti-nuclear antibodies (ANA) by indirect immunofluorescence method (IIF) is unclear and has been inversely associated with rheumatic disease 12.ObjectivesOur purpose was to determine associations between DFS pattern ANA and the disease categories of inflammatory arthritis, ANA associated rheumatic diseases (AARD), fibromyalgia/chronic pain syndrome/chronic fatigue syndrome and atopic disorder.MethodsThis retrospective study used data from patients tested for ANA by IIF between August 2017 to August 2019 at the University of Minnesota Medical Center. Comparisons between the diagnostic categories listed in objectives were made for patients with negative ANA, positive ANA (any pattern) and DFS pattern. Individual disease diagnoses belonging to the above categories were also analyzed. The inflammatory arthritis category included seropositive rheumatoid arthritis (RA), seronegative RA, RA with unknown serology, ankylosing spondylitis, and psoriatic arthritis. The disease category of AARD included systemic lupus erythematosus (SLE), systemic sclerosis, mixed connective tissue disease, idiopathic inflammatory myopathies, Sjogren’s syndrome (SS), and undifferentiated connective tissue disorder (UCTD). Atopic disorders included atopic dermatitis, allergic rhinitis, urticaria, and asthma. Frequency of Raynaud’s phenomenon (RP) was also calculated.Results13,845 patients with an ANA during the study period were identified. 9106 (65.8%) had negative ANA and 4739 (34.2%) had positive ANA by IIF (including all patterns). 640 (4.6%) had ANA positive DFS patterns. Relative risk (RR) was calculated for diagnostic categories and individual diseases. For patients with positive ANA and DFS pattern, the RR for diagnostic codes of inflammatory arthritis categories [1.35 (1.07- 1.71), p=0.02] was higher when compared to the frequency of codes in ANA negative. RR for AARD among patients with DFS pattern was also higher [1.78 (1.44- 2.2), p <0.001]. There was no significant difference in the frequency of diagnostic codes of chronic pain/fibromyalgia/chronic fatigue syndrome [1.02 (0.9- 1.2), p=0.84] atopic disorder [0.68 (0.4- 1.15), p=0.16] for DFS+ compared to the ANA group. The frequency of AARD diagnostic codes was lower for patients with DFS pattern [0.64 (0.52- 0.79), p<0.001] compared to ANA positive patients with all other patterns, consistent with published data. There was no significant difference of frequency of diagnostic codes for the rest of the disease categories when comparison was made between ANA positive DFS pattern and ANA positive with other patterns.Individual disease diagnostic codes of RA were higher among DFS+ patients when compared to ANA- patients. The frequency of diagnostic codes of SLE, SS, UCTD, fibromyalgia, Raynaud’s phenomenon, and autoimmune thyroid disease was also higher among patients with DFS pattern compared to ANA- patients. The frequency of diagnostic codes of seropositive RA was lower among patients with DFS pattern compared to ANA+ with all other patterns. The frequency of diagnostic codes of SLE, SSc, UCTD, and chronic pain was also lower among DFS+ patients, compared to those with ANA of all other patterns, consistent with prior reports.ConclusionThe frequency of diagnostic codes of RA, SS and Raynaud’s was higher among DFS pattern ANA compared to ANA negative group but was not significantly different from ANA positive with other patterns. This suggests that the presence of a DFS pattern should not be used to indiscriminately exclude the presence of a rheumatic disease.References[1]Mariz HA, Sato EI, Barbosa SH, Rodrigues SH, Dellavance A, Andrade LEC. Pattern on the antinuclear antibody-HEp-2 test is a critical parameter for discriminating antinuclear antibody-positive healthy individuals and patients with autoimmune rheumatic diseases. Arthritis Rheum. 2011;63(1):191-200. doi:10.1002/art.30084[2]Watanabe A, Kodera M, Sugiura K, et al. Anti-DFS70 Antibodies in 597 Healthy Hospital Workers. ARTHRITIS Rheum. 2004;50(3):892-900. doi:10.1002/art.20096Disclosure of InterestsNone declared
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Ferjaoui S, Aouini L, Slimane RB, Ammar K, Dreisigacker S, Schouten HJ, Sapkota S, Bahri BA, Ben M'Barek S, Visser RGF, Kema GHJ, Hamza S. Deciphering resistance to Zymoseptoria tritici in the Tunisian durum wheat landrace accession 'Agili39'. BMC Genomics 2022; 23:372. [PMID: 35581550 PMCID: PMC9112612 DOI: 10.1186/s12864-022-08560-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 04/14/2022] [Indexed: 01/28/2023] Open
Abstract
Background Septoria tritici blotch (STB), caused by Zymoseptoria tritici (Z. tritici), is an important biotic threat to durum wheat in the entire Mediterranean Basin. Although most durum wheat cultivars are susceptible to Z. tritici, research in STB resistance in durum wheat has been limited. Results In our study, we have identified resistance to a wide array of Z. tritici isolates in the Tunisian durum wheat landrace accession ‘Agili39’. Subsequently, a recombinant inbred population was developed and tested under greenhouse conditions at the seedling stage with eight Z. tritici isolates and for five years under field conditions with three Z. tritici isolates. Mapping of quantitative trait loci (QTL) resulted in the identification of two major QTL on chromosome 2B designated as Qstb2B_1 and Qstb2B_2. The Qstb2B_1 QTL was mapped at the seedling and the adult plant stage (highest LOD 33.9, explained variance 61.6%), conferring an effective resistance against five Z. tritici isolates. The Qstb2B_2 conferred adult plant resistance (highest LOD 32.9, explained variance 42%) and has been effective at the field trials against two Z. tritici isolates. The physical positions of the flanking markers linked to Qstb2B_1 and Qstb2B_2 indicate that these two QTL are 5 Mb apart. In addition, we identified two minor QTL on chromosomes 1A (Qstb1A) and chromosome 7A (Qstb7A) (highest LODs 4.6 and 4.0, and explained variances of 16% and 9%, respectively) that were specific to three and one Z. tritici isolates, respectively. All identified QTL were derived from the landrace accession Agili39 that represents a valuable source for STB resistance in durum wheat. Conclusion This study demonstrates that Z. tritici resistance in the ‘Agili39’ landrace accession is controlled by two minor and two major QTL acting in an additive mode. We also provide evidence that the broad efficacy of the resistance to STB in ‘Agili 39’ is due to a natural pyramiding of these QTL. A sustainable use of this Z. tritici resistance source and a positive selection of the linked markers to the identified QTL will greatly support effective breeding for Z. tritici resistance in durum wheat. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-022-08560-2.
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Affiliation(s)
- Sahbi Ferjaoui
- Laboratory of Bioaggressors and Integrated Protection in Agriculture (BPIA), National Institute of Agronomy of Tunisia (INAT), 43 Avenue Charles Nicolle, 1082 El Mahrajène, Tunis, Tunisia.,Present Address Field Crops Laboratory, Regional Field Crops Research Center of Beja (CRRGC), P.O. Box 9000, Beja, Tunisia
| | - Lamia Aouini
- Bio-Interaction and Plant Health, Wageningen University and Research, PO Box 16, 6700AA, Wageningen, The Netherlands.,The Graduate School 'Experimental Plant Sciences' (EPS), Wageningen Campus, 6708 PB, Wageningen, The Netherlands.,Present Address Center for Desert Agriculture, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Rim B Slimane
- Laboratory of Bioaggressors and Integrated Protection in Agriculture (BPIA), National Institute of Agronomy of Tunisia (INAT), 43 Avenue Charles Nicolle, 1082 El Mahrajène, Tunis, Tunisia.,Present address Higher Institute of Agronomy of Chott Meriam (ISA-CM), 4042, Sousse, Tunisia
| | - Karim Ammar
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6‑641, 06600, Mexico, D.F., Mexico
| | - Suzanne Dreisigacker
- International Maize and Wheat Improvement Center (CIMMYT), Apdo. Postal 6‑641, 06600, Mexico, D.F., Mexico
| | - Henk J Schouten
- Plant Breeding, Wageningen University and Research, P.O. Box 386, 6700 AJ, Wageningen, The Netherlands
| | - Suraj Sapkota
- Institute of Plant Breeding, Genetics and Genomics, Department of Plant Pathology and Institute of Plant Breeding, University of Georgia, Griffin, GA, 30223, USA.,Present Address United States Department of Agriculture USDA, Crop Genetics and Breeding Research Unit, Tifton, GA, USA
| | - Bochra A Bahri
- Laboratory of Bioaggressors and Integrated Protection in Agriculture (BPIA), National Institute of Agronomy of Tunisia (INAT), 43 Avenue Charles Nicolle, 1082 El Mahrajène, Tunis, Tunisia.,Institute of Plant Breeding, Genetics and Genomics, Department of Plant Pathology and Institute of Plant Breeding, University of Georgia, Griffin, GA, 30223, USA
| | - Sarrah Ben M'Barek
- CRP-Wheat Septoria Phenotyping Platform (CIMMYT-IRESA), Regional Field Crops Research Center of Beja (CRRGC), BP 350, 9000, Beja, Tunisia
| | - Richard G F Visser
- Plant Breeding, Wageningen University and Research, P.O. Box 386, 6700 AJ, Wageningen, The Netherlands
| | - Gert H J Kema
- Bio-Interaction and Plant Health, Wageningen University and Research, PO Box 16, 6700AA, Wageningen, The Netherlands.,Laboratory of Phytopathology, Wageningen University and Research, PO box 16, 6700AA, Wageningen, The Netherlands
| | - Sonia Hamza
- Laboratory of Bioaggressors and Integrated Protection in Agriculture (BPIA), National Institute of Agronomy of Tunisia (INAT), 43 Avenue Charles Nicolle, 1082 El Mahrajène, Tunis, Tunisia.
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Sapkota S, Shrestha S, Bista D, Shrestha A, Maharjan R, Bajracharya S, Jha N, Koju RP, Shrestha R. Medical Products for Cardiovascular Disease Management in Nepal: a needs assessment study. Kathmandu Univ Med J (KUMJ) 2022; 19:18-29. [PMID: 35526133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Background Medical Products and Technologies is a key component of the health system. Quality medicines and efficient management of the medical products can secure effective cardiovascular diseases management. Objective To collate information and identify strengths, weaknesses, opportunities and threats (SWOT) associated with medical products and technology component for cardiovascular disease management in Nepal. Method This study is a part of a larger rapid assessment of Nepal's health system for cardiovascular disease management and based on The Health System Assessment Approach: A How-To Manual (USAID). The authors conducted a desk review of documents related to the WHO "medical product and technology" building block component and key informant interviews using a pre-tested interview protocol. The first eight interviews were transcribed verbatim and analysed inductively to generate a codebook; and the remaining, transcribed and deductively coded based on the codebook. Findings were categorised into relevant topical area and SWOT components. Result Nepal has laws and provisions for medicine regulation, pharmacovigilance, post marketing surveillance, registration and licensing provisions for pharmacy industries/ outlets, essential medicine lists and national formulary. These provisions also apply to medicines used for cardiovascular diseases. The challenge however, is the lack of effective implementation and monitoring, due to shortages of technical workforce and state of art information and technologies. Information on pharmaceutical expenditures for cardiovascular disease management is scarce; there are no standard national level guidelines that are consistently used to manage cardiovascular diseases in health facilities. Conclusion There are limited provisions and information on medical products for cardiovascular disease management in Nepal, and a need to strengthen existing provisions for medicine regulations and surveillance.
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Affiliation(s)
- S Sapkota
- Research Division, Manmohan Memorial Institute of Health Sciences, Soalteemod, Kathmandu, Nepal. Department of Pharmacy, Manmohan Memorial Institute of Health Sciences, Soalteemode, Kathmandu, Nepal. and Fellow, CVD Translational Research Program, Kathmandu University School of Medical Sciences, Dhulikhel, Kavre, Nepal
| | - S Shrestha
- Department of Community Programs, Dhulikhel Hospital-Kathmandu University Hospital, Kavrepalanchowk, Nepal
| | - D Bista
- Fellow, CVD Translational Research Program, Kathmandu University School of Medical Sciences, Dhulikhel, Kavre, Nepal. and Department of Pharmacy, Kathmandu University, Dhulikhel, Kavrepalanchowk, Nepal
| | - A Shrestha
- Department of Community Programs, Dhulikhel Hospital-Kathmandu University Hospital, Kavrepalanchowk, Nepal. Department of Public Health, Kathmandu University School of Medical Sciences, Kavrepalanchowk, Nepal. Department of Chronic Disease Epidemiology, Yale School of Public Health, New Haven, USA. Institute for Implementation Science and Health, Kathmandu, Nepal
| | - R Maharjan
- Department of Community Programs, Dhulikhel Hospital-Kathmandu University Hospital, Kavrepalanchowk, Nepal. and Department of Nursing and Midwifery, Kathmandu University School of Medical Sciences, Dhulikhel, Kavre, Nepal
| | - S Bajracharya
- Department of Community Programs, Dhulikhel Hospital-Kathmandu University Hospital, Kavrepalanchowk, Nepal
| | - N Jha
- Department of Community Programs, Dhulikhel Hospital-Kathmandu University Hospital, Kavrepalanchowk, Nepal
| | - R P Koju
- Dean, Kathmandu University School of Medical Sciences, Kavrepalanchowk, Nepal. and Department of Internal Medicine, Dhulikhel Hospital-Kathmandu University Hospital, Kavrepalanchowk, Nepal
| | - R Shrestha
- Department of Pharmacology, Kathmandu University School of Medical Sciences, Dhulikhel, Kavre, Nepal. and Pharmacovigilance Unit/Research and Development Division, Dhulikhel Hospital, Kathmandu University Hospital, Dhulikhel, Kavre, Nepal
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Abstract
Dollar spot, caused by fungal pathogens Clarireedia spp. (formerly Sclerotinia homoeocarpa), is the most common and widely distributed disease of turfgrass worldwide. It can drastically reduce the quality of turfgrass species and affect their aesthetic value and playability. Management of dollar spot typically includes a costly program of multiple application of fungicides within a growing season. Consequently, there have been reported cases of fungicide resistance in populations of Clarireedia spp. Host resistance could be an important component of dollar spot management; however, this approach has been hampered by the lack of sources of resistance because nearly all known warm- and cool-season turfgrass species are susceptible. With the recent advancement in genome sequencing technologies, studies on pathogen genomics and host-pathogen interactions are emerging with the hope of revealing candidate resistance genes in turfgrass and genes for virulence and pathogenicity in Clarireedia spp. Large-scale screening of turfgrass germplasm and quantitative trait locus (QTL) analysis for dollar spot resistance are important for resistance breeding, but only a handful of such studies have been conducted to date. This review summarizes currently available information on the dollar spot pathosystem, taxonomy, pathogen genomics, host-pathogen interaction, genetics of resistance, and QTL mapping and also provides some thoughts for future research prospects to better manage this disease.
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Affiliation(s)
- Suraj Sapkota
- Department of Plant Pathology, University of Georgia, Griffin, GA 30223
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA 30223
| | - Katherine E Catching
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA 30223
| | - Paul L Raymer
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA 30223
- Department of Crop and Soil Science, University of Georgia, Griffin, GA 30223
| | | | - Bochra A Bahri
- Department of Plant Pathology, University of Georgia, Griffin, GA 30223
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA 30223
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Spratling WT, Sapkota S, Vermeer BC, Mallard J, Ali E, Martinez-Espinoza A, Bahri BA. First Report of Gray Leaf Spot Caused by Pyricularia oryzae (synonym: Magnaporthe oryzae) in Oat (Avena sativa) in Georgia, USA. Plant Dis 2021; 106:763. [PMID: 34455806 DOI: 10.1094/pdis-06-21-1182-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In southeastern U.S., oat (Avena sativa L.) is predominantly grown as a grain or forage crop due to its exceptional palatability (Buntin et al. 2009). In November 2020, leaf spot symptoms were observed in an oat field (cv. Horizon 720) in Screven County, Georgia (GPS: 32°38'57.6"N 81°31'32.178"W). Lesions were oblong, whitish to gray in color, and surrounded by dark brown borders. Symptomatic oat leaves were sampled from the field and cut into 1 cm2 sections that were surface sterilized, plated onto Potato Dextrose Agar (PDA) media and incubated in the dark at 23°C. To obtain pure cultures, fungal hyphal tips were transferred onto fresh PDA plates 3 times. The pathogen was identified as Pyricularia (Magnaporthe) based on typical conidial morphology (Ellis 1971). Conidia were hyaline, pyriform, 2-septate, and displayed a basal hilum. Conidia measured 5.32 to 10.64 μm (average 8.24 μm) wide by 15.96 to 29.26 μm (average 25.40 μm) long. The identification of Pyricularia was further confirmed genetically via PCR amplification followed by sequencing. Genomic DNA was extracted from a 14-day old pure culture using a CTAB method (Doyle and Doyle 1987). The internal transcribed spacer (ITS) region of ribosomal DNA, calmodulin (CaM) gene, and -tubulin (TUB) gene were amplified using ITS5-ITS4 (White et al. 1990), CMD5-CMD6 (Hong et al. 2005), and Bt2a- Bt2b (Glass and Donaldson 1995) primer sets, respectively. Amplicons were Sanger sequenced and blasted against the NCBI database. Results exhibited 100% (ITS), 100% (CaM), and 99.61% (TUB) homology with Pyricularia oryzae Cavara (GenBank accession no. LC554423.1, CP050920.1, and CP050924.1, respectively). The ITS, CaM, and TUB sequences of the isolate were deposited in GenBank as MZ295207, MZ342893, and MZ342894, respectively. In a greenhouse (23°C, 80% RH), Koch's postulates were carried out by using oat seedlings cv. Horizon 270 grown in Kord sheet pots filled with Sun Gro professional growing mix, and a P. oryzae spore suspension containing 104 conidia ml-1. The spore suspension (10 ml) was sprayed with an air sprayer onto 7 pots of oat seedlings at the two-leaf stage. Seven supplementary pots of oat seedlings of the same cultivar were sprayed with sterile water to act as controls. After inoculation, plants were covered with black plastic bags that had been sprayed with sterile water to maintain high humidity and incubated overnight in the greenhouse. The bags were removed the next day, and plants were evaluated for symptoms in the following days. Seven days after inoculation, plants displayed symptoms similar to those found in the original field sample. Control plants showed no symptoms. Pyricularia oryzae was consistently re-isolated from inoculated symptomatic oat tissues. To our knowledge, this is the first report of gray leaf spot caused by P. oryzae on oat in the state of Georgia and in the continental United States. Pyricularia oryzae can infect several graminaceous plants, including agronomically important crops such as rice (Oryza sativa) and wheat (Triticum spp.) (Chung et al. 2020). Phylogenetic analysis on the ITS region using 6 different host lineages was performed and revealed that this oat isolate was most closely related to the Lolium lineage. This outbreak could have economic implications in oat production.
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Affiliation(s)
- Willis Turner Spratling
- University of Georgia, 1355, Plant Pathology, 1109 Experiment Street, Griffin, Griffin, Georgia, United States, 30223
- United States;
| | - Suraj Sapkota
- University of Georgia, 1355, Institute of Plant Breeding, Genetics, and Genomics and Dept. of Plant Pathology, , Athens, Georgia, United States, 30602-0002;
| | | | - Jason Mallard
- University of Georgia, 1355, Cooperative Extension, Sylvania, Georgia, United States;
| | - Emran Ali
- University of Georgia, 1355, 2360 Rainwater Rd, Tifton, Georgia, United States, 31793-5766;
| | - Alfredo Martinez-Espinoza
- University of Georgia, Plant Pathology, 1109 Experiment Street, Griffin, Georgia, United States, 30223;
| | - Bochra Amina Bahri
- University of Georgia, 1355, 1109 Experiment Street, Griffin, Griffin, Georgia, United States, 30223
- university of georgia UGA, 1109 Experiment Street, Georgia;
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Rabbi SMHA, Kumar A, Mohajeri Naraghi S, Simsek S, Sapkota S, Solanki S, Alamri MS, Elias EM, Kianian S, Missaoui A, Mergoum M. Genome-Wide Association Mapping for Yield and Related Traits Under Drought Stressed and Non-stressed Environments in Wheat. Front Genet 2021; 12:649988. [PMID: 34239537 PMCID: PMC8258415 DOI: 10.3389/fgene.2021.649988] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 04/28/2021] [Indexed: 12/02/2022] Open
Abstract
Understanding the genetics of drought tolerance in hard red spring wheat (HRSW) in northern USA is a prerequisite for developing drought-tolerant cultivars for this region. An association mapping (AM) study for drought tolerance in spring wheat in northern USA was undertaken using 361 wheat genotypes and Infinium 90K single-nucleotide polymorphism (SNP) assay. The genotypes were evaluated in nine different locations of North Dakota (ND) for plant height (PH), days to heading (DH), yield (YLD), test weight (TW), and thousand kernel weight (TKW) under rain-fed conditions. Rainfall data and soil type of the locations were used to assess drought conditions. A mixed linear model (MLM), which accounts for population structure and kinship (PC+K), was used for marker–trait association. A total of 69 consistent QTL involved with drought tolerance-related traits were identified, with p ≤ 0.001. Chromosomes 1A, 3A, 3B, 4B, 4D, 5B, 6A, and 6B were identified to harbor major QTL for drought tolerance. Six potential novel QTL were identified on chromosomes 3D, 4A, 5B, 7A, and 7B. The novel QTL were identified for DH, PH, and TKW. The findings of this study can be used in marker-assisted selection (MAS) for drought-tolerance breeding in spring wheat.
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Affiliation(s)
- S M Hisam A Rabbi
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | - Ajay Kumar
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | | | - Senay Simsek
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | - Suraj Sapkota
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA, United States
| | - Shyam Solanki
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, United States
| | - Mohammed S Alamri
- Department of Food Sciences and Nutrition, King Saud University, Riyadh, Saudi Arabia
| | - Elias M Elias
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | - Shahryar Kianian
- United States Department of Agriculture-The Agricultural Research Service (USDA-ARS) Cereal Disease Laboratory, University of Minnesota, St. Paul, MN, United States
| | - Ali Missaoui
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA, United States.,Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, United States
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA, United States.,Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, United States
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10
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Rabbi SMHA, Kumar A, Mohajeri Naraghi S, Sapkota S, Alamri MS, Elias EM, Kianian S, Seetan R, Missaoui A, Solanki S, Mergoum M. Identification of Main-Effect and Environmental Interaction QTL and Their Candidate Genes for Drought Tolerance in a Wheat RIL Population Between Two Elite Spring Cultivars. Front Genet 2021; 12:656037. [PMID: 34220939 PMCID: PMC8249774 DOI: 10.3389/fgene.2021.656037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 05/13/2021] [Indexed: 01/22/2023] Open
Abstract
Understanding the genetics of drought tolerance can expedite the development of drought-tolerant cultivars in wheat. In this study, we dissected the genetics of drought tolerance in spring wheat using a recombinant inbred line (RIL) population derived from a cross between a drought-tolerant cultivar, ‘Reeder’ (PI613586), and a high-yielding but drought-susceptible cultivar, ‘Albany.’ The RIL population was evaluated for grain yield (YLD), grain volume weight (GVW), thousand kernel weight (TKW), plant height (PH), and days to heading (DH) at nine different environments. The Infinium 90 k-based high-density genetic map was generated using 10,657 polymorphic SNP markers representing 2,057 unique loci. Quantitative trait loci (QTL) analysis detected a total of 11 consistent QTL for drought tolerance-related traits. Of these, six QTL were exclusively identified in drought-prone environments, and five were constitutive QTL (identified under both drought and normal conditions). One major QTL on chromosome 7B was identified exclusively under drought environments and explained 13.6% of the phenotypic variation (PV) for YLD. Two other major QTL were detected, one each on chromosomes 7B and 2B under drought-prone environments, and explained 14.86 and 13.94% of phenotypic variation for GVW and YLD, respectively. One novel QTL for drought tolerance was identified on chromosome 2D. In silico expression analysis of candidate genes underlaying the exclusive QTLs associated with drought stress identified the enrichment of ribosomal and chloroplast photosynthesis-associated proteins showing the most expression variability, thus possibly contributing to stress response by modulating the glycosyltransferase (TraesCS6A01G116400) and hexosyltransferase (TraesCS7B01G013300) unique genes present in QTL 21 and 24, respectively. While both parents contributed favorable alleles to these QTL, unexpectedly, the high-yielding and less drought-tolerant parent contributed desirable alleles for drought tolerance at four out of six loci. Regardless of the origin, all QTL with significant drought tolerance could assist significantly in the development of drought-tolerant wheat cultivars, using genomics-assisted breeding approaches.
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Affiliation(s)
- S M Hisam Al Rabbi
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | - Ajay Kumar
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | | | - Suraj Sapkota
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA, United States
| | - Mohammed S Alamri
- Department of Food Science and Nutrition, King Saud University, Riyadh, Saudi Arabia
| | - Elias M Elias
- Department of Plant Sciences, North Dakota State University, Fargo, ND, United States
| | - Shahryar Kianian
- USDA-ARS Cereal Disease Laboratory, University of Minnesota, St. Paul, MN, United States
| | - Raed Seetan
- Department of Computer Science, Slippery Rock University, Slippery Rock, PA, United States
| | - Ali Missaoui
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA, United States.,Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, United States
| | - Shyam Solanki
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, United States
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin, GA, United States.,Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, United States
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Sapkota S, Raymer P, Martinez-Espinoza A, Bahri BA. First report of stem rust, caused by Puccinia graminis, and crown rust, caused by Puccinia coronata var. avenae f. sp. avenae, on tall fescue (Festuca arundinacea) in Georgia, USA. Plant Dis 2021; 105:3748. [PMID: 34114886 DOI: 10.1094/pdis-01-21-0190-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Stem rust, caused by Puccinia graminis, and crown rust, caused by P. coronata, are common rust diseases on cool-season grasses (Karakkat et al. 2018), for which long-distance spore dispersal was recorded in northern US (Harder and Haber 1992). During the summers of 2019 and 2020, severe infection of stem rust and crown rust was observed on > 60% of tall fescue (Festuca arundinacea) germplasm plants in a breeding nursery located at the University of Georgia, Griffin GA. Rust-infected leaves first presented uredinia pustules, then black telia towards the end of the season. The uredinia pustules of stem rust and crown rust were brick-red and, yellow and arranged along the host veins, respectively. The urediniospores were one-celled, round to ovoid and measured from 20.75±2.44 μm (crown rust) to 27±3.60 μm long (stem rust). The teliospores were two-celled and measured from 45.75±10.14 μm (stem rust) to 51.60±4.0 μm long (crown rust) (Leonard et al. 2005; Cummins 1971). Urediniospores of both rusts were collected from infected plants in the field in April of 2020 using a Piston vacuum pump (Welch by Gardner Denver Ltd.) and stored at -80 °C in 1.5 ml Eppendorf tubes. Genomic DNA was extracted by grinding the urediniospores in liquid nitrogen using mortar and pestle, followed by the cetyltrimethylammonium bromide method (Doyle and Doyle 1987). The internal transcribed spacer (ITS) region of the ribosomal DNA was amplified using the ITS5-ITS4 primers (White et al. 1990). BLASTn and phylogenetic analyses revealed that the sequence of stem rust (GenBank acc. no. MW430963) and crown rust (GenBank acc. no. MW431324) pathogens had >99% similarity with P. graminis (GenBank acc. no. HQ317538) and P. coronata var. avenae f. sp. avenae (clade V; Liu and Hambleton 2013) (GenBank acc. no. EU014044), respectively. Pathogenicity tests were conducted on the tall fescue cultivar 'Bandit'. For each rust, 12 pots (10 cm × 10 cm) were planted, each containing 13 seeds in a Sungro professional growing mix soil (Sun Gro Horticulture Distribution Inc.). The plant materials were kept in the greenhouse at 20°C/ 25°C (night/day),15-hrs of light, and watered twice a week for 4-weeks. Urediniospores were recovered from -80°C and allowed to acclimate at room temperature for 1 h. For each rust, 20 ml of suspension containing 1×105 urediniospores ml-1 and 5 μl of Tween-twenty (Agdia Inc. Elkhart, IN) were used to inoculate 6 pots; while 6 control pots were sprayed with sterile water. After inoculation, plants were allowed to dry for 1 h and then transferred to a dark chamber at 20°C and 90% of humidity for 12-15 h. At 10-days post inoculation, all inoculated plants developed rust symptoms identical to those observed in the field, whereas control plants had no symptoms. Stem and crown rust pathogens were re-isolated from the artificially inoculated tall fescue plants. Based on form, size, color and numbers of cells forming the spores, a 1947 Festuca elatior specimen from Georgia mentioning Puccinia coronata (Hanlin 1966), held at the Julian H. Miller Mycological Herbarium (Catalog No. GAM00013162), was discarded as an earlier record of P. coronata var. avenae and could have been misdiagnosed. Due to the fragile integrity of the original infected plant sample as well as the incipient infection, DNA identification was unsuccessful. To our knowledge, this is the first morphological, genetic and taxonomic report of P. graminis and P. coronata var. avenae f. sp. avenae on tall fescue in Georgia, USA.
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Affiliation(s)
- Suraj Sapkota
- University of Georgia, 1355, Institute of Plant Breeding, Genetics, and Genomics and Dept. of Plant Pathology, , Athens, Georgia, United States, 30602-0002;
| | - Paul Raymer
- University of Georgia, Crop and Soil Science, griffin, United States;
| | - Alfredo Martinez-Espinoza
- University of Georgia, Plant Pathology, 1109 Experiment Street, Griffin, Georgia, United States, 30223;
| | - Bochra Amina Bahri
- University of Georgia, 1355, 1109 Experiment Street, Griffin, Griffin, Georgia, United States, 30223
- university of georgia UGA, 1109 Experiment Street, Georgia;
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12
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Ward BP, Merrill K, Bulli P, Pumphrey M, Mason RE, Mergoum M, Johnson J, Sapkota S, Lopez B, Marshall D, Brown-Guedira G. Analysis of the primary sources of quantitative adult plant resistance to stripe rust in U.S. soft red winter wheat germplasm. Plant Genome 2021; 14:e20082. [PMID: 33595199 DOI: 10.1002/tpg2.20082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 11/27/2020] [Indexed: 06/12/2023]
Abstract
Stripe rust, or yellow rust (Puccinia striiformis Westend. f. sp. tritic), is a disease of wheat (Triticum aestivum L.) historically causing significant economic losses in cooler growing regions. Novel isolates of stripe rust with increased tolerance for high temperatures were detected in the United States circa 2000. This increased heat tolerance puts geographic regions, such as the soft red winter wheat (SRWW) growing region of the southeastern United States, at greater risk of stripe rust induced losses. In order to identify sources of stripe rust resistance in contemporary germplasm, we conducted genome-wide association (GWA) studies on stripe rust severity measured in two panels. The first consisted of 273 older varieties, landraces, and some modern elite breeding lines and was evaluated in environments in the U.S. Pacific Northwest and the southeastern United States. The second panel consisted of 588 modern, elite SRWW breeding lines and was evaluated in four environments in Arkansas and Georgia. The analyses identified three major resistance loci on chromosomes: 2AS (presumably the 2NS:2AS alien introgression from Aegilops ventricosa Tausch; syn. Ae. caudata L.), 3BS, and 4BL. The 4BL locus explained a greater portion of variance in resistance than either the 2AS or 3BS loci in southeastern environments. However, its effects were unstable across different environments and sets of germplasm, possibly a result of its involvement in epistatic interactions. Relatively few lines carry resistance alleles at all three loci, suggesting that there is a pre-existing reservoir of enhanced stripe rust resistance that may be further exploited by regional breeding programs.
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Affiliation(s)
- Brian P Ward
- USDA Agricultural Research Service Plant Science Research Unit, Raleigh, NC, 27607, USA
- Current Address: Department of Horticulture and Crop Science, The Ohio State University, Wooster, OH, 44691, USA
| | - Keith Merrill
- Department of Crop and Soil Sciences, North Carolina State University, Raleigh, NC, 27607, USA
| | - Peter Bulli
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Mike Pumphrey
- Department of Crop and Soil Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Richard Esten Mason
- Department of Crop, Soil and Environmental Sciences, University of Arkansas, Fayetteville, AR, 72701, USA
- Current Address: Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, 80523, USA
| | - Mohamed Mergoum
- Department of Crop and Soil Sciences and Institute of Plant Breeding, Genetics & Genomics, University of Georgia, Griffin, GA, 30223, USA
| | - Jerry Johnson
- Department of Crop and Soil Sciences and Institute of Plant Breeding, Genetics & Genomics, University of Georgia, Griffin, GA, 30223, USA
| | - Suraj Sapkota
- Department of Crop and Soil Sciences and Institute of Plant Breeding, Genetics & Genomics, University of Georgia, Griffin, GA, 30223, USA
| | - Benjamin Lopez
- Department of Crop and Soil Sciences and Institute of Plant Breeding, Genetics & Genomics, University of Georgia, Griffin, GA, 30223, USA
| | - David Marshall
- USDA Agricultural Research Service Plant Science Research Unit, Raleigh, NC, 27607, USA
| | - Gina Brown-Guedira
- USDA Agricultural Research Service Plant Science Research Unit, Raleigh, NC, 27607, USA
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Sapkota S, Mergoum M, Kumar A, Fiedler JD, Johnson J, Bland D, Lopez B, Sutton S, Ghimire B, Buck J, Chen Z, Harrison S. A novel adult plant leaf rust resistance gene Lr2K38 mapped on wheat chromosome 1AL. Plant Genome 2020; 13:e20061. [PMID: 33169935 DOI: 10.1002/tpg2.20061] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 09/05/2020] [Indexed: 06/11/2023]
Abstract
Soft red winter wheat (SRWW) cultivar AGS 2038 has a high level of seedling and adult plant leaf rust (LR) resistance. To map and characterize LR resistance in AGS 2038, a recombinant inbred line (RIL) population consisting of 225 lines was developed from a cross between AGS 2038 and moderately resistant line UGA 111729. The parents and RIL population were phenotyped for LR response in three field environments at Plains and Griffin, GA, in the 2017-2018 and 2018-2019 growing seasons, one greenhouse environment at the adult-plant stage, and at seedling stage. The RIL population was genotyped with the Illumina iSelect 90K SNP marker array, and a total of 7667 polymorphic markers representing 1513 unique loci were used to construct a linkage map. Quantitative trait loci (QTL) analysis detected six QTL, QLr.ags-1AL, QLr.ags-2AS, QLr.ags-2BS1, QLr.ags-2BS2, QLr.ags-2BS3, and QLr.ags-2DS, for seedling and adult plant LR resistance. Of these, the major adult plant leaf rust resistance QTL, QLr.ags-1AL, was detected on all field and greenhouse adult plant tests and explained up to 34.45% of the phenotypic variation. QLr.ags-1AL, tightly flanked by IWB20487 and IWA4022 markers, was contributed by AGS 2038. Molecular marker analysis using a diagnostic marker linked to Lr59 showed that QLr.ags-1AL was different from Lr59, the only known LR resistance gene on 1AL. Therefore, the QTL was temporarily designated as Lr2K38. Lr2K38-linked marker IWB20487 was highly polymorphic among 30 SRWW lines and should be useful for selecting the Lr2K38 in wheat breeding programs.
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Affiliation(s)
- Suraj Sapkota
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Ajay Kumar
- Department of Plant Sciences, North Dakota State University, Fargo, ND, 58102, USA
| | - Jason D Fiedler
- USDA-ARS, Cereal Crops Research Unit, Edward T. Schafer Agricultural Research Center, Fargo, ND, 58102, USA
| | - Jerry Johnson
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Dan Bland
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Benjamin Lopez
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Steve Sutton
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Bikash Ghimire
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - James Buck
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Zhenbang Chen
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA, 30223, USA
| | - Stephen Harrison
- School of Plant, Environmental and Soil Sciences, Louisiana State University, Baton Rouge, LA, 70803, USA
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Ghimire B, Sapkota S, Bahri BA, Martinez-Espinoza AD, Buck JW, Mergoum M. Fusarium Head Blight and Rust Diseases in Soft Red Winter Wheat in the Southeast United States: State of the Art, Challenges and Future Perspective for Breeding. Front Plant Sci 2020; 11:1080. [PMID: 32765563 PMCID: PMC7378807 DOI: 10.3389/fpls.2020.01080] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 06/30/2020] [Indexed: 05/21/2023]
Abstract
Among the biotic constraints to wheat (Triticum aestivum L.) production, fusarium head blight (FHB), caused by Fusarium graminearum, leaf rust (LR), caused by Puccinia triticina, and stripe rust (SR) caused by Puccinia striiformis are problematic fungal diseases worldwide. Each can significantly reduce grain yield while FHB causes additional food and feed safety concerns due to mycotoxin contamination of grain. Genetic resistance is the most effective and sustainable approach for managing wheat diseases. In the past 20 years, over 500 quantitative trait loci (QTLs) conferring small to moderate effects for the different FHB resistance types have been reported in wheat. Similarly, 79 Lr-genes and more than 200 QTLs and 82 Yr-genes and 140 QTLs have been reported for seedling and adult plant LR and SR resistance, respectively. Most QTLs conferring rust resistance are race-specific generally conforming to a classical gene-for-gene interaction while resistance to FHB exhibits complex polygenic inheritance with several genetic loci contributing to one resistance type. Identification and deployment of additional genes/QTLs associated with FHB and rust resistance can expedite wheat breeding through marker-assisted and/or genomic selection to combine small-effect QTL in the gene pool. LR disease has been present in the southeast United States for decades while SR and FHB have become increasingly problematic in the past 20 years, with FHB arguably due to increased corn acreage in the region. Currently, QTLs on chromosome 1B from Jamestown, 1A, 1B, 2A, 2B, 2D, 4A, 5A, and 6A from W14, Ning7840, Ernie, Bess, Massey, NC-Neuse, and Truman, and 3B (Fhb1) from Sumai 3 for FHB resistance, Lr9, Lr10, Lr18, Lr24, Lr37, LrA2K, and Lr2K38 genes for LR resistance, and Yr17 and YrR61 for SR resistance have been extensively deployed in southeast wheat breeding programs. This review aims to disclose the current status of FHB, LR, and SR diseases, summarize the genetics of resistance and breeding efforts for the deployment of FHB and rust resistance QTL on soft red winter wheat cultivars, and present breeding strategies to achieve sustainable management of these diseases in the southeast US.
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Affiliation(s)
- Bikash Ghimire
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA, United States
| | - Suraj Sapkota
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA, United States
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin Campus, Griffin, GA, United States
| | - Bochra A. Bahri
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA, United States
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin Campus, Griffin, GA, United States
| | | | - James W. Buck
- Department of Plant Pathology, University of Georgia, Griffin Campus, Griffin, GA, United States
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Griffin Campus, Griffin, GA, United States
- Department of Crop and Soil Sciences, University of Georgia, Griffin Campus, Griffin, GA, United States
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Pradhan S, Babar MA, Bai G, Khan J, Shahi D, Avci M, Guo J, McBreen J, Asseng S, Gezan S, Baik BK, Blount A, Harrison S, Sapkota S, St Amand P, Kunwar S. Genetic dissection of heat-responsive physiological traits to improve adaptation and increase yield potential in soft winter wheat. BMC Genomics 2020; 21:315. [PMID: 32312234 PMCID: PMC7171738 DOI: 10.1186/s12864-020-6717-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 04/05/2020] [Indexed: 12/14/2022] Open
Abstract
Background Climate change, including higher temperatures (HT) has a detrimental impact on wheat productivity and modeling studies predict more frequent heat waves in the future. Wheat growth can be impaired by high daytime and nighttime temperature at any developmental stage, especially during the grain filling stage. Leaf chlorophyll content, leaf greenness, cell membrane thermostability, and canopy temperature have been proposed as candidate traits to improve crop adaptation and yield potential of wheat under HT. Nonetheless, a significant gap exists in knowledge of genetic backgrounds associated with these physiological traits. Identifying genetic loci associated with these traits can facilitate physiological breeding for increased yield potential under high temperature stress condition in wheat. Results We conducted genome-wide association study (GWAS) on a 236 elite soft wheat association mapping panel using 27,466 high quality single nucleotide polymorphism markers. The panel was phenotyped for three years in two locations where heat shock was common. GWAS identified 500 significant marker-trait associations (MTAs) (p ≤ 9.99 × 10− 4). Ten MTAs with pleiotropic effects detected on chromosomes 1D, 2B, 3A, 3B, 6A, 7B, and 7D are potentially important targets for selection. Five MTAs associated with physiological traits had pleiotropic effects on grain yield and yield-related traits. Seventy-five MTAs were consistently expressed over several environments indicating stability and more than half of these stable MTAs were found in genes encoding different types of proteins associated with heat stress. Conclusions We identified 500 significant MTAs in soft winter wheat under HT stress. We found several stable loci across environments and pleiotropic markers controlling physiological and agronomic traits. After further validation, these MTAs can be used in marker-assisted selection and breeding to develop varieties with high stability for grain yield under high temperature.
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Affiliation(s)
- Sumit Pradhan
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Md Ali Babar
- Department of Agronomy, University of Florida, Gainesville, FL, USA.
| | | | - Jahangir Khan
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Dipendra Shahi
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Muhsin Avci
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Jia Guo
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Jordan McBreen
- Department of Agronomy, University of Florida, Gainesville, FL, USA
| | - Senthold Asseng
- Agricultural and Biological Engineering, University of Florida, Gainesville, FL, USA
| | - Salvador Gezan
- School of Forest Resources and Conservation, University of Florida, Gainesville, FL, USA
| | | | - Ann Blount
- North Florida Research and Education Cente, Quincy, FL, USA
| | | | - Suraj Sapkota
- Institute of Plant Breeding, Genetics, and Genomics, University of Georgia, Athens, GA, USA
| | | | - Sanju Kunwar
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI, USA
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Sapkota S, Mergoum M, Liu Z. The translucens group of Xanthomonas translucens: Complicated and important pathogens causing bacterial leaf streak on cereals. Mol Plant Pathol 2020; 21:291-302. [PMID: 31967397 PMCID: PMC7036361 DOI: 10.1111/mpp.12909] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/14/2019] [Accepted: 12/21/2019] [Indexed: 05/31/2023]
Abstract
UNLABELLED Xanthomonas translucens is a group of gram-negative bacteria that can cause important diseases in cereal crops and forage grasses. Different pathovars have been defined according to their host ranges, and molecular and biochemical characteristics. Pathovars have been placed into two major groups: translucens and graminis. The translucens group contains the pathovars causing bacterial leaf streak (BLS) on cereal crops such as wheat, barley, triticale, rye, and oat. In recent years, BLS has re-emerged as a major problem for many wheat- and barley-producing areas worldwide. The biology of the pathogens and the host-pathogen interactions in cereal BLS diseases were poorly understood. However, recent genome sequence data have provided an insight into the bacterial phylogeny and identification and pathogenicity/virulence. Furthermore, identification of sources of resistance to BLS and mapping of the resistance genes have been initiated. TAXONOMY Kingdom Bacteria; Phylum Proteobacteria; Class Gammaproteobacteria; Order Xanthomonadales; Family Xanthomonadaceae; Genus Xanthomonas; Species X. translucens; translucens group pathovars: undulosa, translucens, cerealis, hordei, and secalis; graminis group pathovars: arrhenatheri, graminis, poae, phlei; newly established pathovar: pistaciae. HOST RANGE X. translucens mainly infects plant species in the Poaceae with the translucens group on cereal crop species and the graminis group on forage grass species. However, some strains have been isolated from, and are able to infect, ornamental asparagus and pistachio trees. Most pathovars have a narrow host range, while a few can infect a broad range of hosts. GENOME The complete genome sequence is available for two X. translucens pv. undulosa strains and one pv. translucens strain. A draft genome sequence is also available for at least one strain from each pathovar. The X. translucens pv. undulosa strain Xt4699 was the first to have its complete genome sequenced, which consists of 4,561,137 bp with total GC content approximately at 68% and 3,528 predicted genes. VIRULENCE MECHANISMS Like most xanthomonads, X. translucens utilizes a type III secretion system (T3SS) to deliver a suite of T3SS effectors (T3Es) inside plant cells. Transcription activator-like effectors, a special group of T3Es, have been identified in most of the X. translucens genomes, some of which have been implicated in virulence. Genetic factors determining host range virulence have also been identified.
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Affiliation(s)
- Suraj Sapkota
- Institute of Plant Breeding, Genetics, and GenomicsUniversity of GeorgiaGriffin Campus, GriffinGAUSA
| | - Mohamed Mergoum
- Institute of Plant Breeding, Genetics, and GenomicsUniversity of GeorgiaGriffin Campus, GriffinGAUSA
- Department of Crop and Soil SciencesUniversity of GeorgiaGriffin Campus, GriffinGAUSA
| | - Zhaohui Liu
- Department of Plant PathologyNorth Dakota State UniversityFargoNDUSA
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Sapkota S, Baig S, Hess T, O'Connell AM, Menk J, Shyne M, Fazeli P, Ensrud K, Shmagel A. Vitamin D and bisphosphonate therapy in systemic lupus erythematosus patients who receive glucocorticoids: are we offering the best care? Lupus 2020; 29:263-272. [PMID: 31996109 DOI: 10.1177/0961203320903086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This study aimed to evaluate management practices for glucocorticoid (GC)-induced osteoporosis (GIOP) in systemic lupus erythematosus (SLE) patients using 2017 American College of Rheumatology guidelines as a gold standard. METHODS We conducted a retrospective cohort study using a clinical database from the years 2011 to 2016. SLE cases with >90 days continuous prednisone use at doses of ≥7.51 mg daily were identified. Osteoporosis risk factors were assessed via chart review. The Fracture Risk Assessment (FRAX) score was estimated for patients > 40 years of age. Vitamin D, bisphosphonate prescriptions, and osteoporotic (OP) fractures were ascertained through chart review. A classification tree was used to identify the key patient-related predictors of bisphosphonate prescription. RESULTS A total of 203 SLE patients met the inclusion criteria. The recommended dose of vitamin D supplement was prescribed to 58.9% of patients < 40 years of age and 61.5% of patients ≥ 40 years of age. Among patients aged ≥ 40 years, 25% were prescribed bisphosphonates compared to 36% who met indications for bisphosphonates per the ACR guidelines. Another 10% were prescribed a bisphosphonate, despite not having indication per the ACR guidelines, which was considered as overtreatment. Among patients aged ≥ 40 years, older age and a higher FRAX score for major OP fracture and hip fracture predicted bisphosphonate prescription. In a classification tree analysis, patients with FRAX scores (for major OP fracture) of ≥ 23.5% predicted bisphosphonate prescription in this SLE population. Among patients who had OP fractures in the follow-up period, nine (6.50%) were inpatients receiving appropriate GIOP care versus 12 (13.6%) who were inpatients not receiving ACR-appropriate care (p = 0.098). CONCLUSIONS In clinical practice, fewer SLE patients with or at risk for GIOP are prescribed vitamin D and bisphosphonates than recommended by the 2017 ACR guidelines. Also, in this study, another 10% were prescribed a bisphosphonate, despite not having an indication per the ACR guidelines. Patients were most likely to receive a bisphosphonate prescription if they had a major OP FRAX score of > 23.5%.
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Affiliation(s)
- S Sapkota
- Department of Medicine, University of Minnesota, Minneapolis, USA.,Division of General Internal Medicine, University of Minnesota, Minneapolis, USA
| | - S Baig
- Department of Medicine, University of Minnesota, Minneapolis, USA
| | - T Hess
- University of Minnesota Medical School, University of Minnesota, Minneapolis, USA
| | | | - J Menk
- Biostatistical Design and Analysis Center, Clinical and Translational Science Institute, University of Minnesota, Minneapolis, USA
| | - M Shyne
- Biostatistical Design and Analysis Center, Clinical and Translational Science Institute, University of Minnesota, Minneapolis, USA
| | - P Fazeli
- Department of Medicine, University of Minnesota, Minneapolis, USA.,Division of Rheumatic and Autoimmune Diseases, University of Minnesota, Minneapolis, USA
| | - K Ensrud
- Department of Medicine and Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, USA.,Center for Care Delivery and Outcome Research, Minneapolis VA Health Care System, Minneapolis, USA
| | - A Shmagel
- Department of Medicine, University of Minnesota, Minneapolis, USA.,Division of Rheumatic and Autoimmune Diseases, University of Minnesota, Minneapolis, USA
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Adhikari S, Khadka S, Sapkota S, Sharma BR, Ghimire A, Chalise M, Gurung D, Kunwar S. Multi-drug Resistant and Extended Spectrum β-lactamase Producing Salmonella Species Isolated from Fresh Chicken Liver Samples. Kathmandu Univ Med J (KUMJ) 2020; 18:23-27. [PMID: 33582683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Background Emergence of antibiotic resistance among microbes contaminating the fresh meat products is a global public health concern as they can be easily transmitted to humans through their consumption and contact. Objective The current study was conducted to determine the distribution of antimicrobial resistance among Salmonella species isolated from fresh chicken liver samples with special emphasis on extended spectrum beta-lactamase (ESBL) production. Method A total of 200 fresh chicken liver samples were cultivated for the isolation of Salmonella and further subcultivated to detect extended spectrum beta-lactamase production among them. Antimicrobial susceptibility testing (AST) was done by disk diffusion method using a panel of 7 antimicrobials. Result Out of 200 samples analyzed, 61 (30.5%) samples harbored Salmonella species out of which 15 (7.5%) samples showed the presence of Salmonella Typhi. A significant association was noted in the incidence of Salmonella with various factors pertaining to the butchers, such as age, sex, literacy rate, practices of washing knives and chopping board, wearing aprons and gloves and type of water used (p < 0.05). Salmonella isolates were highly sensitive to amikacin (82.0%) and least sensitive to tetracycline (3.3%). All the isolates were resistant to colistin. Sixty (98.4%) isolates were identified as multi-drug resistant (MDR). The total number of extended spectrum betalactamase producers reported among Salmonella isolates was 29 (47.5%). Conclusion The results indicate that the fresh chicken liver samples sold in Bharatpur Metropolis are reservoirs of multi-drug resistant Salmonella, including extended spectrum betalactamase producers, that could potentially be transmitted to the humans by direct contact or through inadequate cooking.
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Affiliation(s)
- S Adhikari
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal
| | - S Khadka
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal. Department of Biochemistry and Molecular Biology, School of Life Sciences, Central China Normal University, Wuhan, Hubei, 430079, P.R. China
| | - S Sapkota
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal. State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, P.R. China
| | - B R Sharma
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal
| | - A Ghimire
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal
| | - M Chalise
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal
| | - D Gurung
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal
| | - S Kunwar
- Department of Microbiology, Birendra Multiple Campus, Tribhuvan University, Bharatpur, Chitwan, 44200, Nepal
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Sapkota S, Hao Y, Johnson J, Buck J, Aoun M, Mergoum M. Genome-Wide Association Study of a Worldwide Collection of Wheat Genotypes Reveals Novel Quantitative Trait Loci for Leaf Rust Resistance. Plant Genome 2019; 12:1-14. [PMID: 33016598 DOI: 10.3835/plantgenome2019.05.0033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 08/08/2019] [Indexed: 06/11/2023]
Abstract
The emergence of new virulent Puccinia triticina races requires a continuous search for novel sources of resistance to combat leaf rust (LR) disease Twenty-two wheat genotypes resistant to four P. triticina races were identified in this study A genome-wide association study detected 11 quantitative trait loci for LR resistance; five of them were detected on genomic regions where no LR resistant genes have been detected. Wheat (Triticum aestivum L.) production worldwide is being challenged by several biotic and abiotic factors. Leaf rust (LR), caused by Puccinia triticina, is a major biotic constraint of wheat production worldwide. Genetic resistance is the most efficient and cost-effective way to control LR. Seventy-nine LR resistance genes have been identified to date but the frequent emergence of new virulent P. triticina races every year demands a constant search for new sources of resistance with novel quantitative trait loci (QTL) or genes. The objectives of this study were to identify putative novel sources of effective resistance against the current prevalent races of P. triticina in the southeast United States and to map genomic loci associated with LR resistance via a genome-wide association study (GWAS) approach. Evaluation of 331 diverse wheat genotypes against four prevalent P. triticina races (MFGKG, MBTNB, MCTNB, and TCRKG) revealed that the majority of the genotypes were susceptible and only 22 genotypes (6.6%) were resistant to all four P. triticina races. The GWAS detected 11 QTL on nine chromosomes for LR resistance. Of these, six QTL were identified in the vicinity of known genes or QTL; therefore, more studies are warranted to determine their relationship. Five QTL (QLr.uga-1AL, QLr.uga-4AS, QLu.uga-5AS, QLr.uga-5AL, and QLr.uga-7AS) were identified on genomic regions where no LR resistance genes have been identified in wheat, representing potential novel loci for LR resistance. The highly resistant wheat genotypes and novel QTL reported in this study could be used in breeding programs to improve LR resistance.
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Affiliation(s)
- Suraj Sapkota
- Inst. of Plant Breeding, Genetics, and Genomics, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223
| | - Yuanfeng Hao
- Inst. of Crop Sciences, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Jerry Johnson
- Dep. of Crop and Soil Sciences, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223
| | - James Buck
- Dep. of Plant Pathology, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223
| | - Meriem Aoun
- Dep. of Plant Pathology and Plant-Microbe Biology, Cornell Univ., Ithaca, NY, 14853
| | - Mohamed Mergoum
- Dep. of Crop and Soil Sciences, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223
- Inst. of Plant Breeding, Genetics, and Genomics, Univ. of Georgia, Griffin Campus, Griffin, GA, 30223
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Sapkota S, Shrestha A. Community Pharmacy Practice in Nepal- An Underexploited Healthcare Domain. Kathmandu Univ Med J (KUMJ) 2019; 17:158-159. [PMID: 33305739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
| | - A Shrestha
- Department of Public Health, Kathmandu University School of Medical Sciences, Dhulikhel. Department of Chronic Disease Epidemiology, Yale School of Public Health, USA
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Shrestha BK, Ranabhat K, Pant R, Sapkota S, Shrestha S. Neuritic Leprosy; An Intriguing Re-visit to a Forbidden Ailment. Kathmandu Univ Med J (KUMJ) 2019; 17:73-76. [PMID: 31734684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Leprosy is a chronic infectious disease that presents with varied manifestations. Pure neuritic leprosy is one of the rarest forms of the disease which is characterized by nerve involvement without the characteristic cutaneous stigmata. Eleven year old, healthy male presented with progressively increasing painful swelling at the medial aspect of the arm near to the right elbow joint with difficulty in extending right ring and little fingers at interphalangeal joint and numbness in the same region for last 1 year with no cutaneous abnormalities. Physical examination revealed 6x3 cm firm, tender lesion 3 cm proximal to the right elbow joint with positive tinel's sign, without signs of inflammation, along with characteristic claw hand deformity of right hand and atrophy of hypothenar and interossei muscle. Electro-diagnostic testing revealed findings consistent with a right ulnar axonal neuropathy above the elbow. Magnetic resonance imaging revealed well defined heterogeneously hyper intense linear lesion along the course of thickened ulnar nerve in the distal arm extending posterior to the medial condyle. It also showed an oval shaped lesion (2.1x1.0 cm) arising from the same segment of the nerve, without any bony or muscular involvement of that area. The patient underwent surgical exploration and ulnar nerve decompression with biopsy. Pathology revealed necrotizing granulomatous inflammatory acid fast bacilli stain negative lesion, which was histologically consistent with caseous abscess caused by tuberculoid leprosy, pathognomonic for Hansen's disease. He has been started on antibiotic therapy and is referred to leprosy center for further course of management. Pure neuritic leprosy, though rare, should be considered as differential diagnosis in cases presenting with peripheral neuropathy at leprosy-endemic areas. Prompt diagnosis and treatment is imperative to prevent permanent neurological injury.
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Affiliation(s)
- B K Shrestha
- Department of Neurosurgery, Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Bansbari, Kathmandu
| | - K Ranabhat
- Department of Radiology, Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Bansbari, Kathmandu
| | - R Pant
- Department of Pathology, Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Bansbari, Kathmandu
| | - S Sapkota
- Department of Neurosurgery, Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Bansbari, Kathmandu
| | - S Shrestha
- Department of Neurosurgery, Upendra Devkota Memorial National Institute of Neurological and Allied Sciences, Bansbari, Kathmandu
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Sharma A, Poudyal I, Gyawali P, Chapagain S, Pokharel S, Bhandari P, Gyawali M, Malla M, Sapkota S, Mishra S. MS06.1 Preparedness To Deliver Cardiovascular Care: Access To Essential Medicines and Diagnostic Tests In Nepal. Glob Heart 2018. [DOI: 10.1016/j.gheart.2018.09.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Wen A, Jayawardana M, Fiedler J, Sapkota S, Shi G, Peng Z, Liu S, White FF, Bogdanove AJ, Li X, Liu Z. Genetic mapping of a major gene in triticale conferring resistance to bacterial leaf streak. Theor Appl Genet 2018; 131:649-658. [PMID: 29218377 DOI: 10.1007/s00122-017-3026-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 11/21/2017] [Indexed: 06/07/2023]
Abstract
A major gene conferring resistance to bacterial leaf streak was mapped to chromosome 5R in triticale. Bacterial leaf streak (BLS), caused by Xanthomonas translucens pv. undulosa (Xtu), is an important disease of wheat and triticale around the world. Although resistance to BLS is limited in wheat, several triticale accessions have high levels of resistance. To characterize the genetic basis of this resistance, we developed triticale mapping populations using a resistant accession (Siskiyou) and two susceptible accessions (UC38 and Villax St. Jose). Bulked segregant analysis in an F2 population derived from the cross of Siskiyou × UC38 led to the identification of a simple sequence repeat (SSR) marker (XSCM138) on chromosome 5R that co-segregated with the resistance gene. The cross of Siskiyou × Villax St. Jose was advanced into an F2:5 recombinant inbred line population and evaluated for BLS reaction. Genetic linkage maps on this population were assembled with markers generated using genotyping-by-sequencing as well as several SSR markers previously identified on 5R. Quantitative trait locus (QTL) mapping revealed a single major QTL on chromosome 5R, underlined by the same SSR marker as in the Siskiyou × UC38 population. The F1 hybrids of the two crosses were highly resistant to BLS, indicating that resistance is largely dominant. This work will facilitate introgression of this rye-derived BLS resistance gene into the wheat genome by molecular marker-mediated chromosome engineering.
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Affiliation(s)
- Aimin Wen
- Department of Plant Pathology, North Dakota State University, Fargo, ND, USA
| | - Malini Jayawardana
- Department of Plant Pathology, North Dakota State University, Fargo, ND, USA
| | - Jason Fiedler
- Department of Plant Sciences, North Dakota State University, Fargo, ND, USA
| | - Suraj Sapkota
- Department of Plant Pathology, North Dakota State University, Fargo, ND, USA
| | - Gongjun Shi
- Department of Plant Pathology, North Dakota State University, Fargo, ND, USA
| | - Zhao Peng
- Department of Plant Pathology, Kansas State University, Manhattan, KS, USA
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Sanzhen Liu
- Department of Plant Pathology, Kansas State University, Manhattan, KS, USA
| | - Frank F White
- Department of Plant Pathology, University of Florida, Gainesville, FL, USA
| | - Adam J Bogdanove
- Plant Pathology and Plant-Microbe Biology Section, School of Integrative Plant Science, Cornell University, Ithaca, NY, USA
| | - Xuehui Li
- Department of Plant Sciences, North Dakota State University, Fargo, ND, USA.
| | - Zhaohui Liu
- Department of Plant Pathology, North Dakota State University, Fargo, ND, USA.
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Sapkota S, Mahaseth R, Jha K. The use of olanzapine compared to aprepitant as antiemetic for prevention of chemotherapy induced nausea and vomiting in highly emetogenic chemotherapy – a randomized trial. Eur J Cancer 2017. [DOI: 10.1016/s0959-8049(17)30623-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Hage E, Mpamugo O, Ohai C, Sapkota S, Swift C, Wooldridge D, Amar CFL. Identification of six Listeria species by real-time PCR assay. Lett Appl Microbiol 2014; 58:535-40. [PMID: 24461044 DOI: 10.1111/lam.12223] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 01/15/2014] [Accepted: 01/20/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED The Listeria genus comprises 10 recognized species. Listeria monocytogenes causes listeriosis in humans and other animals primarily via contaminated food or animal feed. Listeria ivanovii causes listeriosis in animals and on rare occasions in humans. The identification of nonpathogenic species of Listeria in foods indicates that conditions exist that support the growth of pathogenic strains and is used to facilitate the implementation of control and prevention measures. This study shows the development and evaluation of a 5'exonuclease real-time PCR assay for the rapid identification of Listeria seeligeri, Listeria welshimeri, L. monocytogenes, L. ivanovii, Listeria grayi and Listeria innocua. The assay consists of two triplexes that were evaluated using 53 cultures of Gram-positive bacteria, including 49 Listeria spp. from human, animal, food or food-processing environments. The assay was rapid, specific and reproducible and could identify each of the six species from a mixture of strains. The developed assay proved to be a powerful means of rapidly identifying Listeria species and could be usefully implemented in busy specialist reference laboratories. SIGNIFICANCE AND IMPACT OF THE STUDY The identification of species of Listeria from foods is important to monitor pathogenic strains and facilitates the implementation of control measures. This study shows the development and evaluation of a 5'exonuclease real-time PCR assay for the rapid identification of L. seeligeri, L. welshimeri, L. monocytogenes and L. ivanovii, L. grayi, L. innocua. The developed assay proved to be specific, rapid and reproducible and therefore could be implemented in busy specialist reference laboratories.
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Affiliation(s)
- E Hage
- Gastrointestinal Bacteria Reference Unit, Public Health England, London, UK
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Thapa LJ, Twayana RS, Shilpakar R, Ghimire MR, Shrestha A, Sapkota S, Rana PVS. Clinical profile and outcome of acute encephalitis syndrome (AES) patients treated in College of Medical Sciences-Teaching Hospital. J Coll Med Sci-Nepal 2014. [DOI: 10.3126/jcmsn.v9i2.9685] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Objective: Acute encephalitis syndrome is a cause of significant morbidity and mortality in Nepal. Although Japanese encephalitis virus (JEV) was thought to be a major cause for acute encephalitis syndrome, more non-Japanese encephalitis virus cases are reported. The outcome of patients with acute encephalitis syndrome is variable. Our study was designed to study the clinical profile and outcome of patients with acute encephalitis syndrome managed in tertiary care center in central Nepal. Methods: The record of patients admitted with diagnosis of acute encephalitis syndrome,from January 2010 to December 2010 in College of Medical Sciences-Teaching Hospital (CMS-TH) was reviewed. They were classified clinically as meningitis, encephalitis and meningoencephalitis. The clinical details and reports of the patients were recorded and analyzed. Results: Total of 85 cases of meningitis and encephalitis were identified. Mean age was 19.18 years. Fifty-six (65.9%) patients were males and 29 (34.1%) were females. Sixty (70.58%) patients had meningitis, 8 (9.41%) had encephalitis, and 17 (20.0%) had meningoencephalitis. JE serology was positive in 4 patients (4.7%). Seventy-two (84.7%) patients made full recovery and were discharged from hospital. Thirteen (15.3%) patients left against medical advice (LAMA). Conclusion: Acute encephalitis syndrome is still a major public health problem in Nepal. Few of these patients have Japanese Encephalitis. There is a trend towards improved outcome because of availability of improved health services. However, financial constraint remains a challenge in management of acute encephalitis syndrome. Journal of College of Medical Sciences-Nepal, 2013, Vol-9, No-2, 31-37 DOI: http://dx.doi.org/10.3126/jcmsn.v9i2.9685
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Gupta RK, Agrawal CS, Sah S, Sapkota S, Pathania OP, Sah PL. Bile duct injuries during open and laparoscopic cholecystectomy: management and outcome. J Nepal Health Res Counc 2013; 11:187-193. [PMID: 24362609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND The widespread application of laparoscopic cholecystectomy has led to a rise in the numbers of major bile duct injuries (BDI). Perioperative management of these injuries is complex and challenging. There are few published reports locally regarding the perioperative management of BDI. Purpose of this review was to analyze our experience in diagnosis, management and prevention of BDI. METHODS This study was conducted in department of surgery at B. P. Koirala Institute of Health Sciences. From January 2001 to September 2010, a observational study of all patients with a BDI following cholecystectomy was maintained. Patients' charts were retrospectively reviewed to analyze incidence, type of injury, presentation, and perioperative management of BDI. RESULTS A total of 92 patients had BDI which occurred during cholecystectomy, were analysed retrospectively. There were 60/92 (65.5%) patients with BDI resulting from the wrong identification of the anatomy of the Calot's triangle during cholecystectomy. Abdominal ultrasonography was diagnostic for BDI in 71/90 (78.8%). Magnetic resonance cholangiography could reveal the site of injury, the length of injured bile duct and variation of bile duct tree with a diagnostic rate 22/23 (95.6%). The most common injury was Strasberg's E2 in 65/92 (70.7%). A transection or stricture of the bile duct was repaired by hepaticojejunostomy (83 cases in this series). Seventy-five (81.5%) patients were followed up. The mean follow-up time was 2.6 years (range 0.16-6). Good results were achieved in 62/75 (82.6%) of the patients. CONCLUSIONS The high success rate of bile duct repair in the present study can be attributed to the appropriate timing, meticulous technique and the tertiary care experience.
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Affiliation(s)
- R K Gupta
- Department of Surgery, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
| | - C S Agrawal
- Department of Surgery, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
| | - S Sah
- Department of Surgery, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
| | - S Sapkota
- Department of Surgery, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
| | - O P Pathania
- Department of Surgery, Lady Harding Medical College, New Delhi, India
| | - P L Sah
- Department of Radiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal
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Sapkota S, Kapoor R, Aggrawal A. 60P A RANDOMIZED TRIAL COMPARING CONVENTIONAL FRACTIONATION VERSUS ACCELERATED HYPERFRACTIONATION WITH THREE DIMENSIONAL CONFORMAL RADIOTHERAPY (3D-CRT) AND CONCURRENT CHEMOTHERAPY IN UNRESECTABLE NON SMALL CELL LUNG CANCER. Lung Cancer 2013. [DOI: 10.1016/s0169-5002(13)70281-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gupta RK, Samalavicius NE, Sapkota S, Sah PL, Kafle SU. Colonic inflammatory myofibroblastic tumours: an institutional review. Colorectal Dis 2013; 15:e239-43. [PMID: 23350604 DOI: 10.1111/codi.12149] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2012] [Accepted: 09/13/2012] [Indexed: 02/08/2023]
Abstract
AIM The aim of the study was to present the largest series of colonic inflammatory myofibroblastic tumour (C-IMFT) in the literature so far and to provide a review of this condition. METHOD A retrospective review was carried out of a consecutive series of patients diagnosed with a C-IMFT at a community-based hospital with a specialized gastrointestinal unit between 2002 and 2011. The main outcome measures were success rate and postoperative complications. Using a set of terms we searched the PubMed database for papers published on C-IMFT. We reviewed the data from these studies and case reports. RESULTS There were seven patients with a histopathologically proven C-IMFT. The patients' mean age was 39 ± 11.3 years. Four presented with clinical features of intestinal obstruction of varying severity and three with symptoms of anaemia. Complete surgical resection with end-to-end anastomosis was performed. The gross morphology included polypoidal myxoid tumours that served as a lead point for intussusception in two cases, a whorled mass in two and a circumferential infiltrative tumour in three. Microscopically, all tumours had typical features of IMFT with a variable expression of anaplastic lymphoma kinase (ALK-1) and tumour-free resection margins. All patients were well without local recurrence or metastasis at a mean follow-up of 46.8 ± 11.9 months. CONCLUSION Surgical resection is effective for this rare tumour which mostly behaves in a benign manner. Our review supports the need for patients to be followed up for long periods because of the possibility of metastasis or late recurrence.
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Affiliation(s)
- R K Gupta
- Department of Surgery, B. P. Koirala Institute of Health Sciences, Dharan, Nepal.
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Sapkota S, Sherpa M, Bhattarai B. Incidence of hypertension in patients undergoing surgery at Dhulikhel Hospital-Kathmandu University Hospital. Kathmandu Univ Med J (KUMJ) 2012; 9:40-3. [PMID: 22610867 DOI: 10.3126/kumj.v9i2.6286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Hypertension is an important public health challenge worldwide and is most important modifiable risk factor for cardiovascular, cerebrovascular and renal disease. Blood pressure determination forms an integral part of anaesthesiologist evaluation of his patient condition prior to and during surgery. Data are not available which indicate changes in blood pressure occurring preanaesthetically in hospitalized patients. There are several risks from untreated preoperative hypertension in perioperative and postoperative phase. OBJECTIVE To know the incidence of hypertension in preoperative patients undergoing major surgery. METHODS This retrospective observational study was based on the data collected from preanaesthetic checkup record book from January 2010 to December 2010. RESULTS A total of 955 patients were studied and analyzed in terms of hypertension and demographic characteristics. The total incidence of hypertension in preoperative phase was 10.16%. Among them 64.9% being male and 35.1% female. Maximum incidence was found in age group 50-59 years i.e. 26.6%. Among the case detected maximum patients i.e. 52% were patients with newly diagnosed hypertension and among those under medications 61.1% were using calcium channel blockers. CONCLUSION Knowing the incidence will help in proper preoperative optimization of the hypertensive patients and also help in decreasing the incidence of postoperative complications.
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Affiliation(s)
- S Sapkota
- Department of Anesthesia and Critical Care Medicine, Dhulikhel Hospital-Kathmandu University Hospital, Dhulikhel, Kavre, Nepal
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Abstract
A study was conducted at the Institute of Agriculture and Animal Sciences (IAAS), Rampur, Chitwan from 29 August to 17 October, 2007 to compare the effects of antibiotic (chlortetracycline) and probiotic (Lactobacillus acidophilus) with three herbal growth promoters, Amala (Emblica officinalis),(EO), Tulsi (Ocimum sanctum), (OC) and Aswogandha (Withania somnifera),(WS) on growth performance, feed consumption, feed conversion efficiency, carcass characteristics, and economics of broiler production. The experiment was laid out in a completely randomized design with day-old broiler chick (192) randomly assigned to eight groups containing 8 chick in each and replicated three times. The control group received the maize-soybean based basal diet. In the treatment groups, the basal diet was supplemented with one of the following: antibiotic, probiotics, Tulsi, Amala, and Aswogandha and also in combination of herbs, forming eight treatments respectively. Results showed significantly better production in herbs. Significantly higher digestibility of all the nutrients (P<0.05) was observed in Amala+Tulsi+Aswogandha (T8) supplemented group. Highest body weight (1.440kg) was recorded in birds fed diet supplemented with Amala and Tulsi, and the lowest body weight (1.317kg) was seen in antibiotics (T2) fed birds. The highest income over expenditure (Rs.26.36) was recorded in birds fed diet supplemented with Tulsi (T6), although the difference was not significant among the treatments. Looking at the benefit cost ratio, highest B/C ratio was found in birds supplied with Tulsi (1.19) supplemented diet and minimum (1.12) was recorded in Amala supplied diet. Hence, this experiment showed that herbs as growth promoters can replace antibiotics in the diet of broiler chicken. However, it needs multilocational trials before recommendation for adoption by poultry growers.DOI: http://dx.doi.org/10.3126/njst.v12i0.6478 Nepal Journal of Science and Technology 12 (2011) 41-50
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Adhikari P, Pathak UN, Uprety D, Sapkota S. Profile of ascites patient admitted in Nepal Medical College Teaching Hospital. Nepal Med Coll J 2012; 14:111-113. [PMID: 23671959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Ascites is one of the frequently encountered problems in internal medicine. Common causes of ascites are portal hypertension including cirrhosis of liver and congestive heart failure, hypoalbuminemia associated with nephrotic syndrome, intra-abdominal malignancy and abdominal tuberculosis. We evaluated 43 patients presented with ascites in Nepal Medical College Teaching Hospital (NMCTH). After history taking, clinical examination, imaging studies and laboratory evaluation alcoholic liver disease and abdominal tuberculosis were diagnosed in 19 and 5 patients restively. Constrictive pericarditis was diagnosed in 2 patients and 2 patients were suffering from HCV related liver disease. Present study revealed alcoholic liver disease as the commonest cause of ascites.
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Affiliation(s)
- P Adhikari
- Department of Internal Medicine, Nepal Medical College Teaching Hospital, Jorpati, Kathmandu, Nepal.
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Lavé J, Yule D, Sapkota S, Basant K, Madden C, Attal M, Pandey R. Evidence for a Great Medieval Earthquake (~1100 A.D.) in the Central Himalayas, Nepal. Science 2005; 307:1302-5. [PMID: 15731452 DOI: 10.1126/science.1104804] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Himalayan orogen has produced three thrust earthquakes with moment magnitude (Mw) 7.8 to 8.5 during the past century, yet no surface ruptures associated with these great earthquakes have been documented. Here, we present paleoseismic evidence from east central Nepal that, since approximately 700 A.D., a single earthquake ruptured the Frontal Thrust fault at approximately 1100 A.D., with a surface displacement of approximately 17 (+5/-3) meters and a lateral extent and size that could have exceeded 240 kilometers and approximately Mw 8.8, respectively. Ruptures associated with Mw <8.2 events would contribute to the frontal Himalayas folding but would stop before reaching the surface. These findings could require substantial modifications to current regional seismic hazard models.
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Affiliation(s)
- J Lavé
- Laboratoire de Géodynamique des Chaînes Alpines, BP53, 38041 Grenoble, France.
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