Genetic variation for phytic acid content in mungbean (Vigna radiata L. Wilczek)

AbstractMungbean (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 18.98mgg−1 and 5.85 to 20.02mgg−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 (6.001mgg−1) and JL-781 (6.179mgg−1) showed lowest PA. These lpa sources can be used to develop high-yielding mungbean cultivars with low phytic acid