Wheat Productivity Improvement through Spike Fertility as Selection Criteria under Terminal Drought Stress Conditions

Wheat is an essential cereal crop and a staple food. Low rainfall, extreme temperatures events and un-predictable rainfall distribution are some of the major challenges in wheat productivity under highland regions of Balochistan. Genotypes performing best in one dry year may fail in other year. To develop stable and high yielding wheat varieties under terminal drought conditions, a study was conducted to test wheat using different phenological and morphological traits including spike fertility at anthesis (SF-A) and maturity (SF-M). The experiment was conducted at BARDC, Quetta using 22 genotypes in three replications. The days to heading (DTH) show that late genotypes were susceptible to drought stress with negative correlation with almost all traits. Our results show that wheat genotype BARDC-20 produced maximum yield of 0.458 kg with 1.64 kg biomass yield (BY) and 26.5 harvest index (HI). The spike fertility data was measured which is quotient of spike dry weight at anthesis (SF-A) and grain number. Results show maximum SF-A for genotype BARDC-4 with 52.7 SF through high correlation of SF-A with grain yield (0.43) and (0.62) with GNM. Maximum grain number per meter 6579 was observed for BARDC-9. GY was highly correlated with biomass 0.57 and Harvest index 0.78. Thousand kernel weight data also showed 0.37 correlation while GNM and TKW had low correlation. PC analysis depicted that the first three components revealed 70.6% variation. PCA analysis results show that GY is associated with HI, BY while SF-A is associated with number of tillers, GNM and TKW and both groups are having close relationship. SF-A and GNM could be promising traits for indirect selection under terminal drought stress which can improve grain yield production.