Mungbean (Vigna radiata L. Wilczek) is a short-duration legume crop cultivated for seeds that are rich in protein and carbohydrates. Mungbeans contain phytic acid (PA), an anti-nutritional factor that is the main storage form of organic phosphorus in seeds. It is a strong inhibitor against the absorption of nutrients including iron, zinc, calcium and magnesium in monogastric animals. Genotypes with low phytic acid (lpa) in seed may show increased assimilation of nutrients and be useful in breeding lpa cultivars. The present study was conducted to identify lpa sources, genetic variation, heritability, and association with seed coat color, inorganic phosphorus (IP), and seed size in 102 mungbean genotypes including released varieties, land races, mutants, and wild species grown in two seasons: summer 2011 and rabi 2012. PA and IP in dry seeds were estimated by modified colorimetric method and Chen's modified method, respectively. PA, IP, and 100-seed weight differed significantly in the two seasons. PA content in 102 genotypes ranged from 5.74 to 18.98 mg g −1 and 5.85 to 20.02 mg g −1 in summer 2011 and rabi 2012, respectively. High heritability was found for PA (0.87 and 0.86) and seed size (0.82 and 0.83) but low heritability for IP (0.61 and 0.60). A negative correlation was found between PA and seed size (r = −0.183 and −0.267). Yellow and green seed coat genotypes contained significantly less PA than black seed coat genotypes. Cluster analysis revealed the distinctness of wild species, land races and cultivated varieties on the basis of PA content. The genotypes YBSM (6.001 mg g −1 ) and JL-781 (6.179 mg g −1 ) showed lowest PA. These lpa sources can be used to develop high-yielding mungbean cultivars with low phytic acid.

With 1 figure and 3 tables Abstract Mungbean yellow mosaic virus (MYMV) causes one of the most destructive diseases in mungbean. The objectives of this study were to determine the inheritance of MYMV resistance and to identify the role of each resistance gene. Six crosses between resistant and susceptible genotypes were attempted. An infector row technique was used for evaluating parents, F1 and F2 plants for MYMV resistance. Segregating populations were classified into four reactions viz. susceptible (S), moderately susceptible (MS), moderately resistant (MR) and highly resistant (R) based on the distribution and severity of symptoms. The F1 plants from all six crosses and the susceptible parents showed S reactions, while resistant parents showed R reactions. The segregation of resistance responses in F2 populations in ratios of 9 S : 3 MS : 3 MR : 1 R suggested that the resistance was governed by two recessive genes. When one gene was present in the homozygous recessive condition in different plants, it conferred MR and MS reactions. When both genes were present together in the homozygous recessive condition, plants produced resistant reactions (R).

Yellow mosaic disease (YMD) caused by mungbean yellow mosaic virus (MYMV) is the most important disease of mungbean, causing great yield loss. The present investigation was carried out to study the inheritance and identify molecular markers linked with MYMV resistance gene by using F 1 , F 2 and 167 F 2 : 8 recombinant inbred lines (RILs) developed from the cross 'TM-99-37' (resistant) 9 Mulmarada (susceptible). The F 1 was susceptible, F 2 segregated in 3S:1R phenotypic ratio and RILs segregated in 1S:1R ratio in the field screening indicating that the MYMV resistance gene is governed by a single recessive gene. Of the 140 RAPD primers, 45 primers showing polymorphism in parents were screened using bulked segregant analysis. Three primers amplified specific polymorphic fragments viz. OPB-07 600, OPC-06 1750 and OPB-12 820 . The marker OPB-07 600 was more closely linked (6.8 cM) with a MYMV resistance gene as compared to OPC-06 1750 (22.8 cM) and OPB-12 820 (25.2 cM). The resistance-specific fragment OPB-07 600 was cloned, sequenced and converted into a sequence-characterized amplified region (SCAR) marker and validated in twenty genotypes with different genetic backgrounds.

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