Genetic variability for root dynamics in sorghum [Sorghum bicolor (L.) Moench] for drought tolerance

Abstract

Plant root related traits offer the potential for increasing soil water accessibility, particularly in water-limitedconditions. In the present study, 52 genotypes consisting of 41 improved lines (33 RILs and eight NILs developed fordrought adaptation) and 11 released varieties (landraces and elite cultivars) were evaluated for 10 root-related traits at thereproductive stage in PVC pipes in the greenhouse with two replications under well-watered (WW) and water stress (WS)conditions. Moisture stress reduced root volume, root fresh weight and shoot length whereas it increased root length, rootdry weight, root:shoot length ratio, number of roots, total root length, root length density and root weight density. Geneticvariability and correlation analysis revealed that root length, root volume, root fresh weight, total root length and root:shootlength ratio could be used as a selection criterion for drought tolerance at the reproductive stage. Based on the performanceof the genotypes, six genotypes RL 167, RL 34, RV 48, BJV 362, Phule Suchitra and SPV 86 were identified as bestperforming (root related traits) lines only under water stress condition and STG 44 was identified for both water stress andwell-watered conditions