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Nwe ZM, Htut KN, Aung SLL, Gou YN, Huang CX, Deng JX. Two novel species and a new host record of Alternaria (Pleosporales, Pleosporaceae) from sunflower (Compositae) in Myanmar. MycoKeys 2024; 105:337-354. [PMID: 38883863 PMCID: PMC11179095 DOI: 10.3897/mycokeys.105.123790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Accepted: 05/13/2024] [Indexed: 06/18/2024] Open
Abstract
Sunflower (Helianthusannuus L.) is a widely cultivated, fast-growing crop known for its seeds and oil, with substantial ecological and economic importance globally. However, it faces challenges from leaf diseases caused by Alternaria species, which threaten its yield. Three small-spored Alternaria species were isolated from leaf spot and blight symptoms on sunflower in Myanmar. All the species were determined based on morphological characterization and a multi-locus phylogenetic assessment of seven genes, including the internal transcribed spacer of rDNA region (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), RNA polymerase second largest subunit (RPB2), translation elongation factor 1-α (TEF1), Alternaria major allergen gene (Alt a 1), endopolygalacturonase gene (EndoPG), and an anonymous gene region (OPA10-2). The results introduced two new Alternaria species, A.myanmarensis sp. nov. and A.yamethinensis sp. nov., and a known species of A.burnsii, firstly reported from sunflower.
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Affiliation(s)
- Zin Mar Nwe
- Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China
| | - Khin Nayyi Htut
- MARA Key Laboratory of Sustainable Crop Production in the Middle Reaches of the Yangtze River (Co-Construction by Ministry and Province), Yangtze University, Jingzhou 434025, China
| | - Sein Lai Lai Aung
- Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China
| | - Ya-Nan Gou
- Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China
| | - Cheng-Xin Huang
- Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China
| | - Jian-Xin Deng
- Department of Plant Protection, College of Agriculture, Yangtze University, Jingzhou 434025, China
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Xi M, Deyett E, Stajich JE, El-Kereamy A, Roper MC, Rolshausen PE. Microbiome diversity, composition and assembly in a California citrus orchard. Front Microbiol 2023; 14:1100590. [PMID: 36910183 PMCID: PMC9992537 DOI: 10.3389/fmicb.2023.1100590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/03/2023] [Indexed: 02/24/2023] Open
Abstract
The citrus root and rhizosphere microbiomes have been relatively well described in the literature, especially in the context of Huanglonbing disease. Yet questions addressing the assembly of root microbial endophytes have remained unanswered. In the above ground tree tissues, leaves and stems have been the research focus point, while flush and flower microbiomes, two important tissues in the vegetative and reproductive cycles of the tree, are not well described. In this study, the fungal and bacterial taxa in five biocompartments (bulk soil, rhizosphere, root endosphere, flower and flush) of citrus trees grown in a single California orchard were profiled using an amplicon-based metagenomic Illumina sequencing approach. Trees with no observable signs of abiotic or biotic stresses were sampled for two consecutive years during the floral development phase. The rhizosphere was the most biodiverse compartment compared to bulk soil, root endosphere, flower and flush microbiomes. In addition, the belowground bacteriome was more diverse than the mycobiome. Microbial richness decreased significantly from the root exosphere to the endosphere and was overall low in the above ground tissues. Root endophytic microbial community composition shared strong similarities to the rhizosphere but also contained few taxa from above ground tissues. Our data indicated compartmentalization of the microbiome with distinct profiles between above and below ground microbial communities. However, several taxa were present across all compartments suggesting the existence of a core citrus microbiota. These findings highlight key microbial taxa that could be engineered as biopesticides and biofertilizers for citriculture.
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Affiliation(s)
- MengYuan Xi
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Elizabeth Deyett
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA, United States
| | - Ashraf El-Kereamy
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
| | - M Caroline Roper
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA, United States
| | - Philippe E Rolshausen
- Department of Botany and Plant Sciences, University of California, Riverside, Riverside, CA, United States
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Phylogenetic Analysis and Toxigenic Profile of Alternaria Species Isolated from Chickpeas (Cicer arietinum) in Argentina. DIVERSITY 2022. [DOI: 10.3390/d14110924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chickpeas are a very important legume due to their nutritional richness and high protein content and they are used as food for humans and as fodder for livestock. However, they are susceptible to fungal infections and mycotoxin contamination. The Alternaria genus was among the main fungi isolated from chickpea samples in Argentina. The species within this genus are able to produce several mycotoxins such as alternariol (AOH), alternariol monomethyl ether (AME), and tenuazonic acid (TA). So, the objectives of this study were to identify the Alternaria spp. found in the chickpea samples and to determine their toxigenic potential in vitro. A phylogenetic analysis of 32 Alternaria strains was carried out based on the combined sequences of the tef1, gpd, and Alt a1 genes. All Alternaria strains clustered into the section Alternaria and were identified as A. alternata and A. arborescens. Further, the toxigenic profile of each strain was determined in a ground rice–corn steep liquor medium and analysed by HPLC. Most strains were able to co-produce AOH, AME, and TA. These results indicate a potential risk for human health when consuming chickpeas since this legume could be contaminated with Alternaria and its mycotoxins, which are not yet regulated in food.
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Mycotoxin Production and the Relationship between Microbial Diversity and Mycotoxins in Pyrus bretschneideri Rehd cv. Huangguan Pear. Toxins (Basel) 2022; 14:toxins14100699. [PMID: 36287968 PMCID: PMC9610726 DOI: 10.3390/toxins14100699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/07/2022] [Accepted: 10/09/2022] [Indexed: 01/09/2023] Open
Abstract
Mycotoxins are generated by a series of fungal pathogens in postharvest fruit, resulting in serious health threat to consumers and great economic loss to the fruit storage industry. The microbial differences between rotten and healthy fruit during storage and their relationship with mycotoxin production have not been fully studied. In this study, differences in microbial diversity between rotten and healthy fruit after 30 days of storage at ambient temperature were investigated using high-throughput sequencing technology in 'Huangguan' pear (Pyrus bretschneideri Rehd cv. Huangguan) harvested from five different producing regions of Hebei province, China. The bacterial genus Gluconobacter was much more abundant in rotten fruit (76.24%) than that in healthy fruit (32.36%). In addition, Komagataeibacter and Acetobacter were also relatively higher in abundance in rotten fruit. In contrast, bacterial genera Pantoea, Alistipes, Muribaculaceae, Lactobacillus, and Ruminococcaceae_UCG were found to be more abundant in healthy fruit. Fungal genera including Botryosphaeria, Colletotrichum, Valsa, Alternaria, Rosellinia, Fusarium, and Trichothecium were found to be abundant in rotten fruit. The results of principal coordinate analysis (PCoA) showed that there were significant differences in the microbial diversity of different regions. PAT (patulin) was detected in all rotten fruit samples, while tenuazonic acid (TeA), alternariol (AOH), and alternariolmonomethyl ether (AME) were only detected in samples collected from one region (Weixian). Canonical correlation analysis (CCA) and Pearson correlation analysis showed that the abundance of Alistipes and Pantoea were negatively correlated with the contents of PAT, suggesting that bacterial genera Alistipes and Pantoea have potential in reducing mycotoxin production in 'Huangguan' pear.
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Wang F, Saito S, Michailides TJ, Xiao CL. Baseline Sensitivity of Alternaria alternata and A. arborescens to Natamycin and Control of Alternaria Rot on Stored Mandarin Fruit. PLANT DISEASE 2021; 105:3653-3656. [PMID: 34085850 DOI: 10.1094/pdis-04-21-0809-re] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Alternaria rot caused by Alternaria alternata and A. arborescens is one of the major postharvest diseases on mandarin fruit in California. In this study, natamycin, a newly registered biofungicide, was evaluated for its potential as a postharvest treatment to control Alternaria rot on mandarin fruit. The baseline sensitivities of A. alternata and A. arborescens to natamycin were determined. Effective concentration inhibiting 50% of fungal growth (EC50) values of natamycin for 70 A. alternata isolates ranged from 0.694 to 1.275 µg/ml (mean = 0.921 µg/ml) in a conidial germination assay and from 2.001 to 3.788 µg/ml (mean = 2.797 µg/ml) for 40 A. alternata isolates in a mycelial growth assay. EC50 values of natamycin for 30 A. arborescens isolates ranged from 0.698 to 1.203 µg/ml (mean = 0.923 µg/ml) in a conidial germination assay and from 2.035 to 3.368 µg/ml (mean = 2.658 µg/ml) for 20 A. arborescens isolates in a mycelial growth assay. Control tests on detached mandarin fruit showed that natamycin at both low (460 µg/ml) and high (920 µg/ml) recommended rates significantly reduced disease incidence and severity on mandarin fruit inoculated with Alternaria isolates, regardless of species. High rate of natamycin significantly reduced disease incidence and severity compared with the nontreated control even when natamycin treatment was delayed for 6, 12, and 18 h after inoculation. Our results suggested that natamycin can be an effective postharvest fungicide for control of Alternaria rot on mandarin fruit.
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Affiliation(s)
- Fei Wang
- USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Seiya Saito
- USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
| | - Themis J Michailides
- Department of Plant Pathology, Kearney Agricultural Research and Extension Center, University of California Davis, Parlier, CA 93648
| | - Chang-Lin Xiao
- USDA-Agricultural Research Service, San Joaquin Valley Agricultural Sciences Center, Parlier, CA 93648
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Aloi F, Riolo M, Sanzani SM, Mincuzzi A, Ippolito A, Siciliano I, Pane A, Gullino ML, Cacciola SO. Characterization of Alternaria Species Associated with Heart Rot of Pomegranate Fruit. J Fungi (Basel) 2021; 7:172. [PMID: 33673441 PMCID: PMC7997272 DOI: 10.3390/jof7030172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 12/19/2022] Open
Abstract
This study was aimed at identifying Alternaria species associated with heart rot disease of pomegranate fruit in southern Italy and characterizing their mycotoxigenic profile. A total of 42 Alternaria isolates were characterized. They were obtained from pomegranate fruits with symptoms of heart rot sampled in Apulia and Sicily and grouped into six distinct morphotypes based on macro- and microscopic features. According to multigene phylogenetic analysis, including internal transcribed spacer (ITS), translation elongation factor 1-α (EF-1α), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and a SCAR marker (OPA10-2), 38 isolates of morphotypes 1 to 5 were identified as Alternaria alternata, while isolates of morphotype 6, all from Sicily, clustered within the Alternaria arborescens species complex. In particular, isolates of morphotype 1, the most numerous, clustered with the ex-type isolate of A. alternata, proving to belong to A. alternata. No difference in pathogenicity on pomegranate fruits was found between isolates of A. alternata and A. arborescens and among A. alternata isolates of different morphotypes. The toxigenic profile of isolates varied greatly: in vitro, all 42 isolates produced tenuazonic acid and most of them other mycotoxins, including alternariol, alternariol monomethyl ether, altenuene and tentoxin.
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Affiliation(s)
- Francesco Aloi
- Department of Agriculture, Food and Environment, University of Catania, 95123 Catania, Italy; (F.A.); (M.R.)
- Department of Agricultural, Food and Forest Sciences, University of Palermo, 90128 Palermo, Italy
| | - Mario Riolo
- Department of Agriculture, Food and Environment, University of Catania, 95123 Catania, Italy; (F.A.); (M.R.)
- Council for Agricultural Research and Agricultural Economy Analysis, Research Centre for Olive, Citrus and Tree Fruit–Rende CS (CREA- OFA), 87036 Rende, Italy
- Department of Agricultural Science, Mediterranean University of Reggio Calabria, 89122 Reggio Calabria, Italy
| | | | - Annamaria Mincuzzi
- Department of Soil, Plant, and Food Sciences, University of Bari Aldo Moro, Via Amendola 165/A, 70126 Bari, Italy; (A.M.); (A.I.)
| | - Antonio Ippolito
- Department of Soil, Plant, and Food Sciences, University of Bari Aldo Moro, Via Amendola 165/A, 70126 Bari, Italy; (A.M.); (A.I.)
| | - Ilenia Siciliano
- Agroinnova—Centre of Competence for the Innovation in the Agro-Environmental Sector, University of Turin, 10095 Turin, Italy; (I.S.); (M.L.G.)
| | - Antonella Pane
- Department of Agriculture, Food and Environment, University of Catania, 95123 Catania, Italy; (F.A.); (M.R.)
| | - Maria Lodovica Gullino
- Agroinnova—Centre of Competence for the Innovation in the Agro-Environmental Sector, University of Turin, 10095 Turin, Italy; (I.S.); (M.L.G.)
| | - Santa Olga Cacciola
- Department of Agriculture, Food and Environment, University of Catania, 95123 Catania, Italy; (F.A.); (M.R.)
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