In the area of global warming, heat stress, particularly at the seedling stage, is a major problem that affects the production and productivity of mustard that are grown in cooler climates. Fifty five (ten parents and forty five F1’s) mustard genotypes were evaluated under three environments created by different dates of sowing i.e. timely sown, late sown and very late sown during Rabi 2022-23.The experimental materials were evaluated in Randomized block design with three replications under three date of sowing i.e. timely sown, late sown and very late sowing. In the present study, the heat susceptibility index value of parents and crosses for yield and its contributing characters were calculated and genotypes were classified into four different categories i.e. highly heat tolerant, heat tolerant, moderately heat tolerant and heat susceptible. From the result of heat susceptibility index (HSI), parent LAXMI was found most desirable parents in both late and very late date of sowing. Among the cross BPR 543-2 x PM 25, showed the superiority under heat stress environment for seed yield and more than two characters. These parents and crosses could be utilized as a promising breeding material for the development of heat stress tolerant mustard varieties.

Mustard, heat susceptibility index (HSI) and heat stress

The heat susceptibility index (HSI) values of all genotypes have been ranked for each character as per the criterion mentioned above. The overall ranking that the LAXMI was found most desirable parents in both late and very late dates of sowing. Among the cross, BPR 543-2 x PM 25 showed superiority under a heat stress environment for seed yield and more than two characters.

Anita, Deepak Gupta, S.S. Punia, D.K. Gothwal, Manohar Ram, G.K. Mittal and Anil Kumar (2023). Evaluation of Heat Tolerance Genotypes in Indian Mustard [Brassica juncea (L.) Czern & Coss] based on Heat Susceptibility Index. Biological Forum – An International Journal, 15(11): 230-236.