Selection criteria for water stress in wheat (Triticum aestivum L.)

Abstract

Fifty five wheat genotypes (ten parents, 45 F1s) were evaluated both under normal (NC) and water stress (WS) environments for yield and yield contributing traits, grain yield/plant and biological yield in RBD with 3 replications. Drought susceptibility index (DSI) and index of drought resistance (IDR) at 2-leaf stage were worked out. Sufficient genetic variability was in existence for all the characters studied. The combined analysis of variance over environments indicated the presence of variability among the genotypes, differences in environments and the differential response of genotypes over environments as indicated from their significant mean square values, except for harvest index and spike/plant. Grain yield and biological yield showed maximum sensitivity as affected by (NC) and grain weight showed the least. The positive correlation of grain yield with biological yield and harvest index in (NC), negative correlation of grain yield with (DSI) under (NC) and significant positive correlation of grains/spike and grain weight with grain weight/spike under both the environments revealed that selection must be exercised for high biomass, grain weight/spike and harvest index for yield improvement under water stress (WS) conditions. Path coefficient analysis revealed that biological yield and harvest index exhibited high positive direct effects on grain yield under both the environments. Spike/plant and grain weight/spike had mainly indirect effects on grain yield via biological yield under normal condition (NC).