Variability for grain protein content among germplasm accessions and advanced breeding lines in dolichos bean (Lablab purpureus L. Sweet var. Lignosus Prain)

Abstract

Protein energy malnutrition (PEM) is prevalent in south-east Asian countries including India. Breeding and introduction of grain protein-rich varieties of legumes such as dolichos bean is considered as cost-effective approach to combat PEM. Exploitation of genetic variability within germplasm accessions (GAs) and/or breeding populations is the short-term strategy for identification and delivery of protein-rich dolichos bean cultivars to cater to the immediate needs of the farmers and target population. A set of 118 dolichos bean genotypes consisting of 96 GAs and 20 advanced breeding lines (ABLs) and two released varieties (RVs) was field evaluated in augmented deign for dry grain yield per plant and their grain protein contents were estimated. The grain protein content among the genotypes ranged from 18.82 to 24.5% with a mean of 21.73%. The magnitude of estimates of absolute range, standardized range, and phenotypic coefficient of variation (PCV) for grain protein content was higher among GAs than those among ABLs + RVs. However, average grain protein contents of GAs were comparable to those of ABLs + RVs. Nearly 50% of the genotypes (mostly GAs) had significantly higher grain protein content than those of RVs, HA 3 and HA 4. The grain protein contents of the genotypes were poorly correlated with grain yield per plant. These results are discussed in relation to strategies to breed grain protein-rich dolichos bean cultivars.