Identification of Novel Allelic Diversity Linked to Drought in Synthetic Hexaploid Wheat (SHW)

Abstract

Amongst the cereal crops sown all around the world wheat is most important because it is the primary source of food for over 50% world population. Climatic changes are projected to have a significant impact on temperature and precipitation profiles of Indo Pak- zone effecting grain production of wheat. Drought is one of the leading causes responsible for the reduction of yield ~3 0%) . To fulfill the food demand scientists are trying to develop such varieties of wheat that can cope with drought stress and provide good yield. Newly developed Synthetic derivatives of wheat were produced by crossing Synthetic hexapolids and advance cultivars of wheat. Synthetic wheat varieties with dense and deep root system were reported to perform well under drought stress. This experiment was devised to check the performance under three different water regimes. i.e irrigated, rainfed and water with holding. Genotypes were evaluated against yield and drought related parameters. Drought indices were estimated to identify genotypes that give better yield under water stress. Statistical analysis showed that genotypes which exhibited good yield and tolerate drought were SD-131, SD-164, SD-158, SD-63, SD-192 and SD-153. These genotypes have more TKW, and TY and ST!. Genotypes that showed reduction in yield under stress condition were SD195, SD-218, SD-205, and SD-39. These lines are under process of genotyping at genotyping plate form in Australia using 90K SNP chip on Illurnina plate form. Selected lines will be sent to National wheat disease and yield trail next year for varietal release. Introduction Crop experiences stresses of different types: one out of which is drought stress. Drought tolerance is a complex mechanism, therefore the biochemical, phenological, physiological and the genetic processes regarding drought tolerance are also complex (Reynolds et al., 2005). The current and future research is focusing on increasing wheat production and improving wheat quality with least use of agrochemicals (Shewry, 2009).