CHOICE OF DESIRABLE INDICES FOR EFFECTIVE DISCRIMINATION AND SELECTION OF TERMINAL DROUGHT STRESS TOLERANT DOLICHOS BEAN (Lablab purpureus L. Sweet) GENOTYPES
Loading...
Date
2018-08-01
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Agricultural Sciences, Bangalore
Abstract
Direct selection under moisture stress free (MSF) environments for high
economic product yield (EPY) and for its stability (with minimal reduction in EPY)
under moisture stress (MS) is an effective strategy to breed crop plants for drought
tolerance (DT). Indices that integrate EPY under MSF and MS have been used for
screening and selection of moisture stress tolerant genotypes in several crops. The present
study was aimed at identifying desirable indices from among those reported for effective
discrimination and selection of terminal moisture stress (TMS) tolerant dolichos bean
genotypes. Two experiments were conducted. The 33 genotypes of the first experiment
and 13 genotypes of the second experiment were evaluated under two moisture regimes
(MR), namely, MSF and TMS environments in separate trials following Randomized
Block Design. The genotypes of both the experiments performed differentially across the
two MR for both dry pod and seed yield plant-1. Based on the criteria of both correlation
and discriminating ability of the indices, only three indices namely, stress tolerance index
(STI), modified1 STI (K1STI) and modified2 STI (K2STI) were found desirable to
identify TMS tolerant genotypes of both the experiments. Based on rank sum method,
involving the three indices F3 selections no. 16 & 27 and landraces (GL 6, GL 66, GL
447 and Kadalavare), HA 12-3 and HA 4 were found TMS tolerant. Thus, the three
indices STI, K1STI and K2STI are effective for identifying TMS tolerant genotypes with
high grain yield under MSF and TMS environments in dolichos bean.