Correlation and Heat Susceptible Index Analysis for High Temperature Tolerance in Indian Mustard (Brassica juncea L.)

摘要

An investigation was carried out to visualize the effect of high temperature at terminal stage on reproductive phase, seed filling and associated traits on seed yield in 25 promising mustard (Brassica juncea L.) genotypes. The genotypes were grown inrandomized block design with three replications in two environments i.e. timely sown crop in the 3rd week of October and late sown in the 3rd week of November. Late sown cultivars faced heat stress during seed filling stage resulting in lower yield. Significant genotypic differences existed for all the characters at two dates of sowing and environment had 'a profound impact on the reproductive behavior and seed filling which in turn was associated with yield reduction under terminal heat stress. Significant association of biomass along with the increase in magnitude of association in late sown indicates it to be an important selection trait. Impact of heat stress was least on shriveled seeds in cultivar JGM-03-02 and on fully developed seeds in NRCD509, ORYJ(M)-10-2, RK-03-02 and RL2047. Overall CS-1900-14, PBR1188, PBR-300, PR-2004-2, SKM425 and SKM450 had moderate tolerance for seed filling. Based on the various characters, RL-2047 and RGN-152 were identified as highly tolerant, 10 genotypes as moderately tolerant and 13 as susceptible to terminal high temperature.