Effect of Genotype × Environment interaction for agro-physiological traits in thermo-tolerant early maturing Indian mustard (Brassica juncea L. Czern and Coss) genotypes under heat stress condition

Abstract

Brassica juncea is the predominant oilseed brassica in the Indian subcontinent. It accounts for about 80 per cent of the total area under rapeseed-mustard cultivation in India. A study was carried out at the research farm of ICAR-Directorate of Rapeseed-Mustard Research, Bharatpur during rabi 2018-19, 2019-20 and 2020-21 to study effect of Genotype × Environment interaction and genetic variability of early maturing thermo-tolerant genotypes of Indian mustard (Brassica juncea L. Czern & Coss). G x E interaction was significant for all the characters viz., days to flowering, days to maturity, seed yield (kg/ha), membrane stability index (%), excised leaf- water loss (%), relative water content (RWC %), and water retention capacity of leaves (%) except 1000-seed weight. G x E interaction (linear) was also significant for all these eight characters, indicating substantial amount of predictable G x E interaction. Genotype DRMRHT-13-13-5-4 attained minimum days to maturity (122.88) alongwith regression coefficient near to unity and S2 di near to zero considered as stable. While the genotype DRMRHT-13-13-5-5 attained minimum days to maturity (124.44) alongwith regression coefficient near to unity exhibit average stability. Genotype DRMRHT-13-13-5-4, DRMRHT-13-13-5-5 and DRMRHT-13-22-10 could be included in breeding programme where objective is to develop high yielding and heat tolerant stable genotypes over the environment.