Analysis of Auxin-Encoding Gene Family in Vigna radiata and It's Cross-Species Expression Modulating Waterlogging Tolerance in Wild Vigna umbellata

Mungbean is known to be susceptible to waterlogging (WL) stress. Some of the wild species have the potential to tolerate this through various physiological and molecular mechanisms. Auxin Response Factor (ARF) and Auxin/Indole Acetic Acid (AUX/IAA), an early responsive gene family, has multiple functions in growth, development, and stress tolerance. Here, we report the first comprehensive analysis of the ARF and AUX/IAA gene family in mungbean. A total of 26 ARF and 19 AUX/IAA genes were identified from the mungbean genome. The ARF and AUX/IAA candidates were clearly grouped into two major clades. Further, the subgrouping within the major clades indicated the presence of significant diversity. The gene structure, motif analysis, and protein characterization provided the clue for further fundamental research. Out of the10 selected candidate genes, VrARF-5, VrARF-11, VrARF-25, and VrAUX/IAA-9 were found to significantly multiple-fold gene expression in the hypocotyl region of WL-tolerant wild relatives (PRR 2008-2) provides new insight into a role in the induction of lateral root formation under WL stress. The analysis provides an insight into the structural diversity of ARF and AUX/IAA genes in mungbean. These results increase our understanding of ARF and AUX/IAA genes and therefore offer robust information for functional investigations, which can be taken up in the future and will form a foundation for improving tolerance against waterlogging stress.

Urdbean Leaf Crinkle Virus: A Mystery Waiting to Be Solved

Urdbean leaf crinkle disease (ULCD) affects mainly the urdbean or blackgram (Vigna mungo (L.) Hepper) causing distinct symptoms that often result in serious yield losses. It has been known to occur for more than five decades and is considered to be of viral etiology. The identity of the causal agent, often referred to as the urdbean leaf crinkle virus, is not unequivocally proved. There are few attempts to characterize the causal agent of ULCD; however, there is no unanimity in the results. Recent attempts to characterize the causal agent of ULCD using next-generation sequencing of the virome of ULCD-affected urdbean plants indicated the involvement of cowpea mild mottle virus; however, without conforming through Koch's postulates, the etiology of ULCD remains inconclusive. Claims of different insect vectors involved in the transmission of ULCD make this disease even more mysterious. The information available so far indicates that either two different viruses are causing ULCD or a mixture of viruses is involved. The identity of the virus/es causing ULCD still remains to be unambiguously ascertained. In this review, we attempt to analyze information on the various aspects of ULCD.

Genome wide association analysis for grain micronutrients and anti-nutritional traits in mungbean [Vigna radiata (L.) R. Wilczek] using SNP markers

Mungbean is an important food grain legume for human nutrition and nutritional food due to its nutrient-dense seed, liked palatability, and high digestibility. However, anti-nutritional factors pose a significant risk to improving nutritional quality for bio-fortification. In the present study, genetic architecture of grain micronutrients (grain iron and zinc concentration) and anti-nutritional factors (grain phytic acid and tannin content) in association mapping panel of 145 diverse mungbean were evaluated. Based on all four parameters genotypes PUSA 1333 and IPM 02-19 were observed as desired genotypes as they had high grain iron and zinc concentration but low grain phytic acid and tannin content. The next generation sequencing (NGS)-based genotyping by sequencing (GBS) identified 14,447 genome-wide SNPs in a diverse selected panel of 127 mungbean genotypes. Population admixture analysis revealed the presence of four different ancestries among the genotypes and LD decay of ∼57.6 kb kb physical distance was noted in mungbean chromosomes. Association mapping analysis revealed that a total of 20 significant SNPs were shared by both GLM and Blink models associated with grain micronutrient and anti-nutritional factor traits, with Blink model identifying 35 putative SNPs. Further, this study identified the 185 putative candidate genes. Including potential candidate genes Vradi07g30190, Vradi01g09630, and Vradi09g05450 were found to be associated with grain iron concentration, Vradi10g04830 with grain zinc concentration, Vradi08g09870 and Vradi01g11110 with grain phytic acid content and Vradi04g11580 and Vradi06g15090 with grain tannin content. Moreover, two genes Vradi07g15310 and Vradi09g05480 showed significant variation in protein structure between native and mutated versions. The identified SNPs and candidate genes are potential powerful tools to provide the essential information for genetic studies and marker-assisted breeding program for nutritional improvement in mungbean.

Implications of exposing mungbean (Vigna radiata L.) plant to higher CO2 concentration on seed quality

Understanding the crop response to elevated carbon dioxide (e[CO₂]) condition is important and has attracted considerable interest owing to the variability and crop-specific response. In mungbean, reports are available regarding the effect of e[CO₂] on its growth, physiology and yield. However, no information are available on the germination and vigour status of seeds produced at e[CO₂]. Therefore, in the present investigation, mungbean (Virat) was grown in the open top chamber during summer season of 2018 and 2019 to study the implications of e[CO₂] (600 ppm) on quality of the harvested seeds (germination and vigour). The exposure of mungbean plant to e[CO₂] had no major impact on seed quality as the percent viability (normal seedling + hard seeds) was not reduced. However, in one season (2018), the seed germination (normal seedling) was slightly reduced from 72 to 68%, attributed majorly to an increase in the hard seeds (from 13 to 19%), a predominant form of seed dormancy in mungbean. The changes in seed germination were apparent only in first year of the experiment. Accelerated ageing test (AAT) and storage studies revealed no differences in the vigour of seeds produced at ambient and e[CO₂] environments. Also, the seeds from e[CO₂] had low protein and sugar but recorded higher starch content than the seeds from ambient [CO₂].

Association mapping for important agronomic traits in wild and cultivated Vigna species using cross-species and cross-genera simple sequence repeat markers

The genus Vigna is an agronomically important taxon, with many of its species inhabiting a wide range of environments and offering numerous useful genes for the improvement of the cultivated types. The present study aimed to detect the genomic regions associated with yield-attributing traits by genome-wide association mapping. A diverse panel of 98 wild and cultivated Vigna accessions (acc.) belonging to 13 different species was evaluated for yield and related traits during the kharif season of 2017 and 2018. The panel was also genotyped using 92 cross-genera and cross-species simple sequence repeat markers to study the population genetic structure and useful market-trait associations. The PCA and trait correlation established relationships amongst the traits during both seasons while 100-seed weight (HSW) had a positive correlation with pod length (PL), and days to first flowering (DFF) with days to maturity (DM). The population genetic structure analysis grouped different acc. into three genetically distinct sub-populations with SP-1 comprising 34 acc., SP-2 (24 acc.), and SP-3 (33 acc.) and one admixture group (7 acc.). Mixed linear model analysis revealed an association of 13 markers, namely, VR018, VR039, VR022, CEDG033, GMES0337, MBSSR008, CEDG220, VM27, CP1225, CP08695, CEDG100, CEDG008, and CEDG096A with nine traits. Seven of the aforementioned markers, namely, VR018 for plant height (PH) and terminal leaflet length (TLL), VR022 for HSW and pod length (PL), CEDG033 for DFF and DM, MBSSR008 for DFF and DM, CP1225 for CC at 30 days (CC30), DFF and DM, CEDG100 for PH and terminal leaflet length (TLL), and CEDG096A for CC30 and chlorophyll content at 45 days were associated with multiple traits. The marker CEDG100, associated with HSW, PH, and TLL, is co-localized in gene-encoding histone-lysine N-methyltransferase ATX5. Similarly, VR22, associated with PL and HSW, is co-located in gene-encoding SHOOT GRAVITROPISM 5 in mungbean. These associations may be highly useful for marker-assisted genetic improvement of mungbean and other related Vigna species.

Genetic mapping of QTLs for drought tolerance in chickpea (Cicer arietinum L.)

Chickpea yield is severely affected by drought stress, which is a complex quantitative trait regulated by multiple small-effect genes. Identifying genomic regions associated with drought tolerance component traits may increase our understanding of drought tolerance mechanisms and assist in the development of drought-tolerant varieties. Here, a total of 187 F8 recombinant inbred lines (RILs) developed from an interspecific cross between drought-tolerant genotype GPF 2 (Cicer arietinum) and drought-sensitive accession ILWC 292 (C. reticulatum) were evaluated to identify quantitative trait loci (QTLs) associated with drought tolerance component traits. A total of 21 traits, including 12 morpho-physiological traits and nine root-related traits, were studied under rainfed and irrigated conditions. Composite interval mapping identified 31 QTLs at Ludhiana and 23 QTLs at Faridkot locations for morphological and physiological traits, and seven QTLs were identified for root-related traits. QTL analysis identified eight consensus QTLs for six traits and five QTL clusters containing QTLs for multiple traits on linkage groups CaLG04 and CaLG06. The identified major QTLs and genomic regions associated with drought tolerance component traits can be introgressed into elite cultivars using genomics-assisted breeding to enhance drought tolerance in chickpea.

Development of High Yielding Fusarium Wilt Resistant Cultivar by Pyramiding of “Genes” Through Marker-Assisted Backcrossing in Chickpea (Cicer arietinum L.)

Pusa 391, a mega desi chickpea variety with medium maturity duration is extensively cultivated in the Central Zone of India. Of late, this variety has become susceptible to Fusarium wilt (FW), which has drastic impact on its yield. Presence of variability in the wilt causing pathogen, Fusarium oxysporum f.sp. ciceri (foc) across geographical locations necessitates the role of pyramiding for FW resistance for different races (foc 1,2,3,4 and 5). Subsequently, the introgression lines developed in Pusa 391 genetic background were subjected to foreground selection using three SSR markers (GA16, TA 27 and TA 96) while 48 SSR markers uniformly distributed on all chromosomes, were used for background selection to observe the recovery of recurrent parent genome (RPG). BC1F1 lines with 75–85% RPG recovery were used to generate BC2F1. The plants that showed more than 90% RPG recovery in BC2F1 were used for generating BC3F1. The plants that showed more than 96% RPG recovery were selected and selfed to generate BC3F3. Multi-location evaluation of advanced introgression lines (BC2F3) in six locations for grain yield (kg/ha), days to fifty percent flowering, days to maturity, 100 seed weight and disease incidence was done. In case of disease incidence, the genotype IL1 (BGM 20211) was highly resistant to FW in Junagarh, Indore, New Delhi, Badnapur and moderately resistant at Sehore and Nandyal. GGE biplot analysis revealed that IL1(BGM20211) was the most stable genotype at Junagadh, Sehore and Nandyal. GGE biplot analysis revealed that IL1(BGM 20211) and IL4(BGM 20212) were the top performers in yield and highly stable across six environments and were nominated for Advanced Varietal Trials (AVT) of AICRP (All India Coordinated Research Project on Chickpea) in 2018–19. BGM20211 and BGM 20212 recorded 29 and 28.5% average yield gain over the recurrent parent Pusa 391, in the AVT-1 and AVT-2 over five environments. Thus, BGM20211 was identified for release and notified as Pusa Manav/Pusa Chickpea 20211 for Madhya Pradesh, Gujarat and Maharashtra, Southern Rajasthan, Bundhelkhand region of Uttar Pradesh states by the Central Sub-Committees on Crop Standards, Notification and Release of Varieties of Agricultural Crops, Ministry of Agriculture and Farmers Welfare, Government of India, for commercial cultivation in India (Gazette notification number S.O.500 (E) dt. 29-1-2021).Such pyramided lines give resilience to multiple races of fusarium wilt with added yield advantage.

Genome-Wide Analysis of Late Embryogenesis Abundant Protein Gene Family in Vigna Species and Expression of VrLEA Encoding Genes in Vigna glabrescens Reveal Its Role in Heat Tolerance

Late embryogenesis abundant (LEA) proteins are identified in many crops for their response and role in adaptation to various abiotic stresses, such as drought, salinity, and temperature. The LEA genes have been studied systematically in several crops but not in Vigna crops. In this study, we reported the first comprehensive analysis of the LEA gene family in three legume species, namely, mung bean (Vigna radiata), adzuki bean (Vigna angularis), and cowpea (Vigna unguiculata), and the cross-species expression of VrLEA genes in a wild tetraploid species, Vigna glabrescens. A total of 201 LEA genes from three Vigna crops were identified harboring the LEA conserved motif. Among these 55, 64, and 82 LEA genes were identified in mung bean, adzuki bean, and cowpea genomes, respectively. These LEA genes were grouped into eight different classes. Our analysis revealed that the cowpea genome comprised all eight classes of LEA genes, whereas the LEA-6 class was absent in the mung bean genome. Similarly, LEA-5 and LEA-6 were absent in the adzuki bean genome. The analysis of LEA genes provides an insight into their structural and functional diversity in the Vigna genome. The genes, such as VrLEA-2, VrLEA-40, VrLEA-47, and VrLEA-55, were significantly upregulated in the heat-tolerant genotype under stress conditions indicating the basis of heat tolerance. The successful amplification and expression of VrLEA genes in V. glabrescens indicated the utility of the developed markers in mung bean improvement. The results of this study increase our understanding of LEA genes and provide robust candidate genes for future functional investigations and a basis for improving heat stress tolerance in Vigna crops.

Insights into the genetic diversity of an underutilized Indian legume, Vigna stipulacea (Lam.) Kuntz., using morphological traits and microsatellite markers

Vigna stipulacea (Lam.) Kuntz., commonly known as Minni payaru is an underutilized legume species and has a great potential to be utilized as food crop. To evaluate and select the best germplasm to be harnessed in the breeding programme, we assessed the genetic diversity of V. stipulacea (94 accessions) conserved in the Indian National Genebank, based on morphological traits and microsatellite markers. Significant variation was recorded for the morphological traits studied. Euclidean distance using UPGMA method grouped all accessions into two major clusters. Accessions were identified for key agronomic traits such as, early flowering (IC331436, IC251436, IC331437); long peduncle length (IC553518, IC550531, IC553557, IC553540, IC550532, IC553564); and more number of seeds per pod (IC553529, IC622865, IC622867, IC553528). To analyse the genetic diversity among the germplasm 33 SSR primers were used anda total of 116 alleles were detected. The number of alleles varied from two to seven, with an average of 3.52 per loci. The polymorphic information content values varied from 0.20 to 0.74, with a mean of 0.40. The high number of alleles per locus and the allelic diversity in the studied germplasm indicated a relatively wider genetic base of V. stipulacea. Phylogenetic analysis clustered accessions into seven clades. Population structure analysis grouped them into five genetic groups, which were partly supported by PCoA and phylogenetic tree. Besides, PCoA and AMOVA also decoded high genetic diversity among the V. stipulacea accessions. Thus, morphological and microsatellite markers distinguished V. stipulacea accessions and assessed their genetic diversity efficiently. The identified promising accessions can be utilized in Vigna improvement programme through introgression breeding and/or can be used for domestication and enhanced utilization of V. stipulacea.

Association Mapping for Yield Attributing Traits and Yellow Mosaic Disease Resistance in Mung Bean [Vigna radiata (L.) Wilczek]

Mung bean [Vigna radiata (L.) Wilczek] is an important short-duration grain legume widely known for its nutritional, soil ameliorative, and cropping system intensification properties. This study aims at evaluating genetic diversity among mung bean genotypes and detecting genomic regions associated with various yield attributing traits and yellow mosaic disease (YMD) resistance by association mapping. A panel of 80 cultivars and advanced breeding lines was evaluated for 10 yield-related and YMD resistance traits during kharif (monsoon) and summer seasons of 2018-2019 and 2019-2020. A total of 164 genome-wide simple sequence repeat (SSR) markers were initially screened, out of which 89 were found polymorphic which generated 317 polymorphic alleles with an average of 3.56 alleles per SSR locus. The number of alleles at each locus varied from 2 to 7. The population genetic structure analysis grouped different genotypes in three major clusters and three genetically distinct subpopulations (SPs) (i.e., SP-1, SP-2, and SP-3) with one admixture subpopulation (SP-4). Both cluster and population genetic structure analysis categorized the advanced mung bean genotypes in a single group/SP and the released varieties in other groups/SPs, suggesting that the studied genotypes may have common ancestral history at some level. The population genetic structure was also in agreement with the genetic diversity analysis. The estimate of the average degree of linkage disequilibrium (LD) present at the genome level in 80 mung bean genotypes unveiled significant LD blocks. Over the four seasons, 10 marker-trait associations were observed significant for YMD and four seed yield (SY)-related traits viz., days to flowering, days to maturity, plant height, and number of pods per plant using the mixed linear model (MLM) method. These associations may be useful for marker-assisted mung bean yield improvement programs and YMD resistance.

Understanding G × E Interaction for Nutritional and Antinutritional Factors in a Diverse Panel of Vigna stipulacea (Lam.) Kuntz Germplasm Tested Over the Locations

Micronutrient malnutrition or hidden hunger is a serious challenge toward societal well-being. Vigna stipulacea (Lam.) Kuntz (known locally as Minni payaru), is an underutilized legume that has the potential to be a global food legume due to its rich nutrient profile. In the present study, 99 accessions of V. stipulacea were tested for iron (Fe), zinc (Zn), calcium (Ca), protein, and phytate concentrations over two locations for appraisal of stable nutrient-rich sources. Analysis of variance revealed significant effects of genotype for all the traits over both locations. Fe concentration ranged from 29.35-130.96 mg kg-1 whereas Zn concentration ranged from 19.44 to 74.20 mg kg-1 across both locations. The highest grain Ca concentration was 251.50 mg kg-1 whereas the highest grain protein concentration was recorded as 25.73%. In the case of grain phytate concentration, a genotype with the lowest value is desirable. IC622867 (G-99) was the lowest phytate containing accession at both locations. All the studied traits revealed highly significant genotypic variances and highly significant genotype × location interaction though less in magnitude than the genotypic variance. GGE Biplot analysis detected that, for grain Fe, Zn, and Ca concentration the 'ideal' genotypes were IC331457 (G-75), IC331610 (G-76), and IC553564 (G-60), respectively, whereas for grain protein concentration IC553521 (G-27) was the most "ideal type." For phytate concentration, IC351407 (G-95) and IC550523 (G-99) were considered as 'ideal' and 'desirable,' respectively. Based on the desirability index, Location 1 (Kanpur) was identified as ideal for Fe, Zn, Ca, and phytate, and for grain protein concentration, Location 2 (New Delhi) was the ideal type. A significant positive correlation was detected between grain Fe as well as grain Zn and protein concentration considering the pooled analysis over both the locations where as a significant negative association was observed between phytate and protein concentration over the locations. This study has identified useful donors and enhanced our knowledge toward the development of biofortified Vigna cultivars. Promoting domestication of this nutrient-rich semi-domesticated, underutilized species will boost sustainable agriculture and will contribute toward alleviating hidden hunger.

Genetic diversity and population genetic structure analysis of an extensive collection of wild and cultivated Vigna accessions

Vigna is a large, pan-tropic and highly variable group of the legumes family which is known for its > 10 cultivated species having significant commercial value for their nutritious grains and multifarious uses. The wild vignas are considered a reservoir of numerous useful traits which can be deployed for introgression of resistance to biotic and abiotic stresses, seed quality and enhanced survival capability in extreme environments. Nonetheless, for their effective utilization through introgression breeding information on their genetic diversity, population structure and crossability is imperative. Keeping this in view, the present experiment was undertaken with 119 accessions including 99 wild Vigna accessions belonging to 19 species and 18 cultivated genotypes of Vigna and 2 of Phaseolus. Total 102 polymorphic SSRs were deployed to characterize the material at molecular level which produced 1758 alleles. The genotypes were grouped into four major clusters which were further sub-divided in nine sub-clusters. Interestingly, all cultivated species shared a single cluster while no such similarities were observed for the wild accessions as these were distributed in different groups of sub-clusters. The co-dominant allelic data of 114 accessions were then utilized for obtaining status of the accessions and their hybrid forms. The model-based population structure analysis categorized 114 accessions of Vigna into 6 genetically distinct sub-populations (K = 6) following admixture-model based simulation with varying levels of admixture. 91 (79.82%) accessions resembled their hierarchy and 23 (20.18%) accessions were observed as the admixture forms. Maximum number of accessions (25) were grouped in sub-population (SP) 6 and the least accessions were grouped in SP3 and SP5 (11 each). The population genetic structure, therefore, supported genetic diversity analysis and provided an insight into the genetic lineage of these species which will help in effective use of germplasm for development of cultivars following selective prebreeding activities.

Microsatellite-based association mapping for agronomic traits in mungbean (Vigna radiata L. Wilczek)

Mungbean (Vigna radiata L. Wilczek) is one of the most important warm season food legumes which contributes significantly towards nutritional security and environmental sustainability. Marker-trait association (MTA) for agronomic characters offer opportunities to deploy marker-assisted breeding for genetic amelioration of crops. This investigation was carried out with an objective to decipher population genetic structure of diverse Vigna accessions and detect microsatellite loci linked to major agronomic traits for mungbean improvement. The study was initiated with 290 diverse Vigna accessions including wild and cultivated accessions. A mungbean yellow mosaic India virus (MYMIV)-resistant association mapping panel was constructed to minimize the effect of yellow mosaic disease on crop performance. Among these, 117 accessions including 55 cultivated and 63 wild accessions were found highly resistant to MYMIV. After multi-environment phenotyping, a panel of 70 MYMIV-resistant mungbean accessions was subjected to analysis for assessing the population genetic structure as well as MTA for important agronomic traits. There was sufficient genetic variation among the 70-mungbean genotypes as depicted by 91 microsatellite markers. Population genetic structure analysis grouped the genotypes into five subpopulations. The locus GMES0162 (LG4) was strongly associated with days to first flowering, whereas loci CEDG 035 (LG8), DMB SSR001 (LG6), DMB SSR008 (LG4) and CEDG 168 (LG11) were associated with pod number. These marker-trait associations will be helpful in genetic improvement of mungbean through molecular breeding.

Association mapping for mungbean yellow mosaic India virus resistance in mungbean (Vigna radiata L. Wilczek)

The present study aimed to detect the marker-trait association of a selected diverse panel of 127 mungbean genotypes against mungbean yellow mosaic India virus (MYMIV). Virus-specific primers pairs viz., AC-abut/AV-abut and BC-abut/BV-abut confirmed the involvement of MYMIV in yellow mosaic disease development and the same was validated through restriction digestion analysis. 256 genome-wide microsatellite markers were screened on a test panel in which 93 polymorphic markers were used in association studies. Population structure analysis led to formation of six distinct subpopulations. 1097 alleles were detected among 127 test genotypes whereas number of alleles ranged 2-22 and PIC values ranged 0.27-0.92%, indicating ample amount of variation at genome level. 15 microsatellite markers were detected as associated with MYMIV resistance, among them three microsatellites explained 11-14% phenotypic variation. The specific regions close to CEDG293, DMB-SSR008 and DMB-SSR059 associated with MYMIV resistance were detected, located on linkage group 2, 4 and 9 and may prove useful in marker-assisted mungbean improvement programme for enhancing MYMIV resistance.

Current Perspectives on Introgression Breeding in Food Legumes

Food legumes are important for defeating malnutrition and sustaining agri-food systems globally. Breeding efforts in legume crops have been largely confined to the exploitation of genetic variation available within the primary genepool, resulting in narrow genetic base. Introgression as a breeding scheme has been remarkably successful for an array of inheritance and molecular studies in food legumes. Crop wild relatives (CWRs), landraces, and exotic germplasm offer great potential for introgression of novel variation not only to widen the genetic base of the elite genepool for continuous incremental gains over breeding cycles but also to discover the cryptic genetic variation hitherto unexpressed. CWRs also harbor positive quantitative trait loci (QTLs) for improving agronomic traits. However, for transferring polygenic traits, "specialized population concept" has been advocated for transferring QTLs from CWR into elite backgrounds. Recently, introgression breeding has been successful in developing improved cultivars in chickpea (Cicer arietinum), pigeonpea (Cajanus cajan), peanut (Arachis hypogaea), lentil (Lens culinaris), mungbean (Vigna radiata), urdbean (Vigna mungo), and common bean (Phaseolus vulgaris). Successful examples indicated that the usable genetic variation could be exploited by unleashing new gene recombination and hidden variability even in late filial generations. In mungbean alone, distant hybridization has been deployed to develop seven improved commercial cultivars, whereas in urdbean, three such cultivars have been reported. Similarly, in chickpea, three superior cultivars have been developed from crosses between C. arietinum and Cicer reticulatum. Pigeonpea has benefited the most where different cytoplasmic male sterility genes have been transferred from CWRs, whereas a number of disease-resistant germplasm have also been developed in Phaseolus. As vertical gene transfer has resulted in most of the useful gene introgressions of practical importance in food legumes, the horizontal gene transfer through transgenic technology, somatic hybridization, and, more recently, intragenesis also offer promise. The gains through introgression breeding are significant and underline the need of bringing it in the purview of mainstream breeding while deploying tools and techniques to increase the recombination rate in wide crosses and reduce the linkage drag. The resurgence of interest in introgression breeding needs to be capitalized for development of commercial food legume cultivars.

Physiological Traits for Shortening Crop Duration and Improving Productivity of Greengram (Vigna radiata L. Wilczek) Under High Temperature

Greengram is an important protein-rich food legume crop. During the reproductive stage, high temperatures cause flower drop, induce male sterility, impair anthesis, and shortens the grain-filling period. Initially, 116 genotypes were evaluated for 3 years in two locations, and based on flowering, biomass, and yield attributes, they were grouped into four major clusters. A panel of 17 contrasting genotypes was selected for their heat tolerance in high-temperature greenhouses. The seedlings of the selected genotypes were exposed to heat shock in the range 37°C-52°C and their recovery after heat shock was assessed at 30°C. The seedlings of EC 398889 turned completely green and rejuvenated, while those of LGG 460 failed to recover, therefore, EC 398889 and LGG 460 were identified as heat-tolerant and heat-sensitive genotypes, respectively. Except for EC 398889, the remaining genotypes could not survive after heat shock. Fresh seeds of EC 398889 and LGG 460 were planted in field and pollen fertility and sucrose-synthase (SuSy) activity in grains were assessed at high temperatures. The pollen germination and SuSy activity were normal even at temperatures beyond 40°C in EC 398889 and high SuSy activity enabled faster grain filling than in LGG 460. The precise phenotyping demonstrated significant differences in the light-temperature response of photosynthesis, chlorophyll fluorescence imaging of quantum yield (Fv/Fm), and electron transport rate (ETR) between heat-tolerant (EC 398889) and heat-sensitive (LGG 460) genotypes. Molecular profiling of selected accessions showed polymorphism with 11 SSR markers and the markers CEDG147, CEDG247, and CEDG044 distinguished tolerant and sensitive groups of accessions.

Biotic and Abiotic Constraints in Mungbean Production-Progress in Genetic Improvement

Mungbean [Vigna radiata (L.) R. Wilczek var. radiata] is an important food and cash legume crop in Asia. Development of short duration varieties has paved the way for the expansion of mungbean into other regions such as Sub-Saharan Africa and South America. Mungbean productivity is constrained by biotic and abiotic factors. Bruchids, whitefly, thrips, stem fly, aphids, and pod borers are the major insect-pests. The major diseases of mungbean are yellow mosaic, anthracnose, powdery mildew, Cercospora leaf spot, halo blight, bacterial leaf spot, and tan spot. Key abiotic stresses affecting mungbean production are drought, waterlogging, salinity, and heat stress. Mungbean breeding has been critical in developing varieties with resistance to biotic and abiotic factors, but there are many constraints still to address that include the precise and accurate identification of resistance source(s) for some of the traits and the traits conferred by multi genes. Latest technologies in phenotyping, genomics, proteomics, and metabolomics could be of great help to understand insect/pathogen-plant, plant-environment interactions and the key components responsible for resistance to biotic and abiotic stresses. This review discusses current biotic and abiotic constraints in mungbean production and the challenges in genetic improvement.

Association of ITGAM, TNFSF4, TNFAIP3 and STAT4 gene polymorphisms with risk of systemic lupus erythematosus in a North Indian population

Several susceptibility genes have been associated with systemic lupus erythematosus (SLE) across different populations worldwide. However, data on association between genetic polymorphisms and SLE from Indian population is scarce. We aimed to replicate the association of single nucleotide polymorphisms (SNPs) in ITGAM, TNFSF4, TNFAIP3 and STAT4 genes with susceptibility to SLE in a North Indian population. Three hundred and ninety-four SLE patients and 583 unrelated healthy controls of the same ethnic background were enrolled. All samples were genotyped for SNPs in ITGAM (rs1143679), TNFSF4 (rs2205960), TNFAIP3 (rs5029939) and STAT4 (rs7574865) using TaqMan genotyping assay. At allele level, significant association with susceptibility to SLE was detected with polymorphisms in ITGAM (A vs. G, odds ratio (OR) = 1.73, 95% confidence interval (CI) = 1.30–2.30, p < 0.001), TNFSF4 (T vs. G, OR = 1.33, 95% CI = 1.08–1.64, p < 0.01), TNFAIP3 (G vs. C, OR = 1.91, 95% CI = 1.27–2.85, p < 0.01) and STAT4 (T vs. G, OR = 1.38, 95% CI = 1.13–1.69, p < 0.01). All four SNPs were associated with SLE under a dominant model with an OR of 1.47 (95% CI = 1.07–2.04, p < 0.05) for ITGAM, 1.30 (95% CI = 1.01–1.69, p < 0.05) for TNFSF4, 1.90 (95% CI = 1.25–2.90, p < 0.01) for TNFAIP3 and 1.38 (95% CI = 1.06–1.78, p < 0.05) for STAT4. Under a recessive model, significant association was found with ITGAM (OR = 4.87, 95% CI = 2.17–10.91, p < 0.001), TNFSF4 (OR = 1.84, 95% CI = 1.13–3.00, p < 0.05) and STAT4 (OR = 1.82, 95% CI = 1.19–2.77, p < 0.01). In conclusion, single nucleotide polymorphisms in ITGAM, TNFSF4, TNFAIP3 and STAT4 genes are associated with susceptibility to SLE in a North Indian population.

Marker-assisted introgression of resistance to fusarium wilt race 2 in Pusa 256, an elite cultivar of desi chickpea

Fusarium wilt caused by F. oxysporum f. sp. ciceris causes extensive damage to chickpea (Cicer arietinum L.) in many parts of the world. In the central part of India, pathogen race 2 (Foc 2) causes severe yield losses. We initiated molecular marker-assisted backcrossing (MABC) using desi cultivar, Vijay, as a donor to introgress resistance to this race (Foc2) in Pusa 256, another elite desi cultivar of chickpea. To confirm introgression of resistance for this race, foreground selection was undertaken using two SSR markers (TA 37 and TA110), with background selection to observe the recovery of recurrent parent genome using 45 SSRs accommodated in 8 multiplexes. F₁ plants were confirmed with molecular markers and backcrossed with Pusa 256, followed by cycles of foreground and background selection at each stage to generate 161 plants in BC₃F₂ during the period 2009-2013. Similarly, 46 BC₃F₁ plants were also generated in another set during the same period. On the basis of foreground selection, 46 plants were found homozygotes in BC₃F₂. Among them, 17 plants recorded >91% background recovery with the highest recovery percentage of 96%. In BC₃F₁ also, 14 hybrid plants recorded a background recovery of >85% with the highest background recovery percentage of >94%. The identified plants were selfed to obtain 1341 BC₃F₃ and 2198 BC₃F₂ seeds which were screened phenotypically for resistance to fusarium wilt (race 2) besides doing marker analysis. Finally, 17 BC₃F₄ and 11 BC₃F₃ lines were obtained which led to identification of 5 highly resistant lines of Pusa 256 with Foc 2 gene introgressed in them. Development of these lines will help in horizontal as well as vertical expansion of chickpea in central part of India.

Marker-assisted introgression of resistance to fusarium wilt race 2 in Pusa 256, an elite cultivar of desi chickpea

Fusarium wilt caused by F. oxysporum f. sp. ciceris causes extensive damage to chickpea (Cicer arietinum L.) in many parts of the world. In the central part of India, pathogen race 2 (Foc 2) causes severe yield losses. We initiated molecular marker-assisted backcrossing (MABC) using desi cultivar, Vijay, as a donor to introgress resistance to this race (Foc2) in Pusa 256, another elite desi cultivar of chickpea. To confirm introgression of resistance for this race, foreground selection was undertaken using two SSR markers (TA 37 and TA110), with background selection to observe the recovery of recurrent parent genome using 45 SSRs accommodated in 8 multiplexes. F₁ plants were confirmed with molecular markers and backcrossed with Pusa 256, followed by cycles of foreground and background selection at each stage to generate 161 plants in BC₃F₂ during the period 2009-2013. Similarly, 46 BC₃F₁ plants were also generated in another set during the same period. On the basis of foreground selection, 46 plants were found homozygotes in BC₃F₂. Among them, 17 plants recorded >91% background recovery with the highest recovery percentage of 96%. In BC₃F₁ also, 14 hybrid plants recorded a background recovery of >85% with the highest background recovery percentage of >94%. The identified plants were selfed to obtain 1341 BC₃F₃ and 2198 BC₃F₂ seeds which were screened phenotypically for resistance to fusarium wilt (race 2) besides doing marker analysis. Finally, 17 BC₃F₄ and 11 BC₃F₃ lines were obtained which led to identification of 5 highly resistant lines of Pusa 256 with Foc 2 gene introgressed in them. Development of these lines will help in horizontal as well as vertical expansion of chickpea in central part of India.

Achievements and prospects of genomics-assisted breeding in three legume crops of the semi-arid tropics

Advances in next-generation sequencing and genotyping technologies have enabled generation of large-scale genomic resources such as molecular markers, transcript reads and BAC-end sequences (BESs) in chickpea, pigeonpea and groundnut, three major legume crops of the semi-arid tropics. Comprehensive transcriptome assemblies and genome sequences have either been developed or underway in these crops. Based on these resources, dense genetic maps, QTL maps as well as physical maps for these legume species have also been developed. As a result, these crops have graduated from 'orphan' or 'less-studied' crops to 'genomic resources rich' crops. This article summarizes the above-mentioned advances in genomics and genomics-assisted breeding applications in the form of marker-assisted selection (MAS) for hybrid purity assessment in pigeonpea; marker-assisted backcrossing (MABC) for introgressing QTL region for drought-tolerance related traits, Fusarium wilt (FW) resistance and Ascochyta blight (AB) resistance in chickpea; late leaf spot (LLS), leaf rust and nematode resistance in groundnut. We critically present the case of use of other modern breeding approaches like marker-assisted recurrent selection (MARS) and genomic selection (GS) to utilize the full potential of genomics-assisted breeding for developing superior cultivars with enhanced tolerance to various environmental stresses. In addition, this article recommends the use of advanced-backcross (AB-backcross) breeding and development of specialized populations such as multi-parents advanced generation intercross (MAGIC) for creating new variations that will help in developing superior lines with broadened genetic base. In summary, we propose the use of integrated genomics and breeding approach in these legume crops to enhance crop productivity in marginal environments ensuring food security in developing countries.

Characterization of a new begomovirus and a beta satellite associated with the leaf curl disease of French bean in northern India

Begomoviruses are emerging as serious threat to many crops throughout the world particularly in tropical and sub-tropical regions. A leaf curl disease with symptoms typical of infection by many begomoviruses was observed in French bean (Phaseolus vulgaris) at Kanpur, India, during 2010-2012. The disease caused downward leaf curling and made the plants unproductive. The disease was transmitted from infected to healthy plants through whitefly (Bemisia tabaci). The products of five samples digested with EcoRI yielded DNA fragments of about 2.7 kb. The complete sequence of the Fb1 sample comprised 2,741 nucleotides with genome organization typical of begomoviruses having two ORFs in virion-sense and five ORFs in complementary-sense separated by an intergenic region with begomovirus conserved nonanucleotide sequence, TAATATTAC. The complete DNA-A sequence homology was most closely related to Cotton leaf curl Bangalore virus with 80 % nucleotide sequence identity. Based on the demarcation criteria for identifying a begomovirus species, Fb1 is considered as a distinct begomovirus species, named French bean leaf curl virus and designated as FbLCV-[IN:Knp:12]. The complete sequence of associated satellite DNA-β comprises 1,379 nucleotides with single ORF and has 80 % identity with Papaya leaf curl beta satellite. There was no evidence of recombination in DNA-A of FbLCV and associated beta satellite DNA molecule.

Intracranial Ricocheting of Bullet from Anterior Clinoid Process

Gunshot wounds to the head are usually mortal injuries. We present a unique case of intracranial ricocheting of bullet without neurological deficits. Patient was treated conservatively with antibiotics for one week and prophylactic anticonvulsants for six weeks. Patient is doing well at six months follow up. Repeat X-ray skull showed that bullet was lying in the occipital region. It is recommended that deep seated bullets should be left behind as any attempt to remove that bullet may increase the morbidity and mortality. However close follow up of these patients is very important as these patients may come back with brain abscess.JNMA J Nepal Med Assoc. 2008 Jul-Sep;47(171):145-146.

Intracranial ricocheting of bullet from anterior clinoid process

Gunshot wounds to the head are usually mortal injuries. We present a unique case of intracranial ricocheting of bullet without neurological deficits. Patient was treated conservatively with antibiotics for one week and prophylactic anticonvulsants for six weeks. Patient is doing well at six months follow up. Repeat X-ray skull showed that bullet was lying in the occipital region. It is recommended that deep seated bullets should be left behind as any attempt to remove that bullet may increase the morbidity and mortality. However close follow up of these patients is very important as these patients may come back with brain abscess.

Anaesthetic Management of Tracheal Agenesis

Tracheal agenesis is a rare but uniformly fatal congenital condition that obstetricians, neonatologists or anaesthesiologists may encounter as an unexpected emergency. Ventilation with bag and mask or through an endotracheal tube placed in the oesophagus may be the only options left for immediate survival and evaluation. Ventilation and maintenance of adequate oxygenation can be difficult during surgical interventions. We report a case of neonate in which ventilation and anaesthesia were maintained through an endotracheal tube in the oesophagus and frequent episodes of drop in oxygen saturation were observed during surgery. Anaesthetic management, airway and other issues are discussed.JNMA J Nepal Med Assoc. 2008 Jul-Sep;47(171):142-144.

Anaesthetic management of tracheal agenesis

Tracheal agenesis is a rare but uniformly fatal congenital condition that obstetricians, neonatologists or anaesthesiologists may encounter as an unexpected emergency. Ventilation with bag and mask or through an endotracheal tube placed in the oesophagus may be the only options left for immediate survival and evaluation. Ventilation and maintenance of adequate oxygenation can be difficult during surgical interventions. We report a case of neonate in which ventilation and anaesthesia were maintained through an endotracheal tube in the oesophagus and frequent episodes of drop in oxygen saturation were observed during surgery. Anaesthetic management, airway and other issues are discussed.

Full counting statistics as the geometry of two planes

Provided the measuring time is short enough, the full counting statistics (FCS) of the charge pumped across a barrier as a result of a series of voltage pulses are shown to be equivalent to the geometry of two planes. This formulation leads to the FCS without the need for the usual nonequilibrium (Keldysh) transport theory or the direct computation of the determinant of an infinite-dimensional matrix. In the particular case of the application of N Lorentzian pulses, we show the computation of the FCS reduces to the diagonalization of an N x N matrix. We also use the formulation to compute the core-hole response in the x-ray edge problem and the FCS for a square wave pulse-train for the case of low transmission.

Isolated accessory limb of lower eyelid with multiple dermal appendages

We report the first case in the English literature of an isolated occurrence of accessory limb with multiple dermal appendages in a ten-month-old boy. This condition presented at birth as a limb bud below the left eyelid, multiple dermal appendages in the adjacent part of the face below the left orbit and on the upper part of the face. No anomalies of the ocular structures or central nervous system were identified. Accessory limb with multiple dermal appendages, in the absence of a congenital cystic eye, is an extremely rare condition representing a benign aberration in the developing musculoskeletal system. We present the first of such a case and endeavour to explain the embryological basis behind it.

Congenital unilateral lower lip palsy and eventration of diaphragm

Congenital unilateral lower lip palsy is a rare but well-known limited variation of congenital unilateral facial palsy. We report a three-month-old boy with diaphragmatic eventration and isolated lower lip palsy, a combination that to our knowledge, has not been described before. Probable causes of this combination of multiple congenital malformations, in this case, could be due to nonrandom and heterogeneous mutations. The diaphragmatic eventration was treated successfully.

Fryns syndrome: a lethal mesoectodermal birth defect with variable expression in a pair of monozygotic twins

We report a pair of twins with variable expressions of Fryns syndrome, both of whom died in the neonatal period. The syndrome is characterised by craniofacial dysmorphism, diaphragmatic hernia and distal limb hypoplasia. With this report, there are a total of 83 cases reported in the literature and this further serves to illustrate the clinical variability of this disorder.

The Walker-Warburg syndrome with cleft lip and palate

The Walker-Warburg syndrome is a rare and lethal autosomal recessive disorder. We report a newborn male infant with the Walker-Warburg syndrome. He had typical clinical features, including lissencephaly, congenital muscular dystrophy and an ocular abnormality associated with cleft lip and palate without hydrocephalus.

Apert syndrome with septum pellucidum agenesis

Apert syndrome is characterised by craniosynostosis, associated with maxillary hypoplasia, symmetrical syndactyly of the hands and feet, and other systemic malformations including mental retardation. Apert syndrome and septo-optic dysplasia is rarely described. We describe the classical clinical and radiological findings of this syndrome in a 20-year-old woman. Though early surgical intervention is imperative for optimal outcome, in developing countries, it may not be possible to intervene at the right time due to financial constraints.

Evaluation of cerebral vascular reserve by single photon emission tomography in children with congenital hydrocephalus

BACKGROUND/AIMS

Single photon emission tomography scan (SPECT) is used to measure cerebral blood flow (CBF) and also cerebral vascular reserve (CVR) after intravenous acetazolamide (ACZ) challenge. This prospective study was designed to test the utility of CVR in congenital hydrocephalus (CHC).

METHODS

Patients (n = 21, mean age 6.2 m) with CHC underwent a baseline ultrasonography (US), retinal fundus examination (RF), neurological score (NS), and SPECT to evaluate CVR after intravenous ACZ. Monthly US, RF, NS, CBF, and CVR were evaluated.

RESULTS

Ten patients showed good CVR and also had stable NS and RF despite mild to moderate ventriculomegaly and were followed up on conservative treatment. None of these patients in a mean follow-up period of 9.8 months showed deterioration. Eleven patients, who had poor CVR initially, were also treated conservatively. Over a period of 4 months, 8 patients showed a fall in CVR to < 30 % of baseline and a fall in NS despite RF and US remaining the same and hence were operated. Five of these operated cases showed an improvement in CVR and NS over a mean follow-up period of 4 months and the remaining 3 patients failed to show improvement in CVR and NS.

CONCLUSIONS

In CHC, CVR measured by ACZ challenge test is a sensitive parameter as alterations in CVR occur prior to changes in other conventional parameters such as ventriculomegaly and RF. Patients with normal CVR at presentation are unlikely to deteriorate and can safely be managed conservatively. Patients who show a deterioration in CVR should be considered for prompt surgery.