EVALUATION OF SPRING WHEAT GENOTYPES FOR TERMINAL HEAT STRESS

Plant breeders exploit available germplasm for the development and improvement of different wheat genotypes. Cell membrane thermostability (CMT) and relative water content (RWC) are good selection criteria for effective selection against heat tolerance. This investigation, 120 spring wheat genotypes were evaluated for the effect of heat stress. Among the 120 spring wheat genotypes, five were identified as heat-tolerant (HT) genotypes, whereas five were found to be heat-susceptible (HS) genotypes on the basis of their relative values of CMT, RWC, and grain yield per plant (GYP). In this experiment, 120 spring wheat genotypes were used to evaluate heat tolerance in an open field (normal) and in a tunnel (heat stress). Analysis of variance depicted highly significant differences among genotypes under both environments. Higher values of CMT and RWC along with GYP were associated with heat tolerance and vice versa. The best-performing HT genotypes under both environmental conditions were V-13248, V-13013, AARI-11, MIRAJ-08, and V-12103. They could be used as donors for heat stress tolerance in breeding program. Among the 120 wheat genotypes, ND643, V-12082, V-12056, WBLL1, and V-12066 were proven to be HS genotypes in both environments. Given that the identified superior HT genotypes can cope with heat stress, they can be utilized for developing HT genotypes. In addition to grain yield, CMT and RWC are good markers for the development of HT wheat genotypes.