Genetic variation for root architectural traits in response to phosphorus deficiency in mungbean at the seedling stage

Abstract

Roots enable the plant to survive in natural environment by providing anchorage and acquisition of water and nutrients. In this study, 153 mungbean genotypes were studied to compare root architectural traits under normal and low phosphorus conditions. Significant variations, medium to high heritability, near normal distribution and significant correlations were observed for studied root traits. Total root length (TRL) was positively correlated with total surface area (TSA), total root volume (TRV), total root tips (TRT) and root forks. The first two principal components explained the 79.19 % and 78.84% of the total variation under normal and low phosphorus conditions. TRL, TSA and TRV were major contributors of variation and can be utilized for screening of phosphorus uptake efficiency at seedling stage. Released Indian mungbean varieties were found to be superior for root traits than other genotypic groups. Based on comprehensive phosphorus efficiency measurement, IPM-288, TM 96-25, TM 96-2, M 1477, PUSA 1342 were found to be best five highly efficient genotypes whereas M 1131, PS-16, Pusa Vishal, M 831, IC 325828 were highly inefficient genotypes. These identified highly efficient lines are valuable genetic resources for phosphorus uptake efficiency that could be used in mungbean breeding programme.