Evaluation of Bread Wheat Genotypes for Water Stress Tolerance Using Agronomic Traits

Abstract

Water stress is one of the major environmental constraints on wheat grain yield worldwide. One way to overcome this limitation is to evolve genetically stress-tolerant wheat genotypes that produce sustainable grain yields in water-scarce conditions. A field experiment was carried out to investigate the genetic diversity of 34 advanced wheat genotypes (<i>Triticum aestivum</i> L.) and two commercial check varieties (Khirman and TD-1) for grain yield and yield-associated agronomic traits in moisture stress (MS) and well-watered (WW) conditions. Plants were grown in residual moisture in rice fallow land in rainfed conditions without supplementary irrigation, i.e., MS conditions, while two rounds of irrigations were applied for the WW control conditions. Analysis of variance indicated a highly significant (<i>p</i> < 0.05) variation among genotypes for all the observed agronomic traits in MS and WW conditions. In the MS group, the exotic line IBWSN-1010, mutant line MASR-64, and doubled haploid line DH-12/7 produced the highest grain yield compared to all the contesting wheat genotypes, including check varieties. Grain yield per plot was positively correlated (<i>r</i> = 0.93) with biological yield per plot in MS conditions. Principal component analysis showed total variations of 21.9%, 20.4%, and 10.1% explained by PC-1, PC-2, and PC-3 in MS, and 22.9%, 14.8%, and 12.1% for PC-1, PC-2, and PC-3 in WW conditions. Our study provides valid information for the selection of newly evolved wheat genotypes and will be useful in future breeding programs.