Impact of Soil Drought on Yield and Leaf Sugar Content in Wheat: Genotypic and Phenotypic Relationships Compared Using a Doubled Haploid Population.

Improving yield stability under water-limited conditions is a key objective of wheat breeding programmes. One trait of particular interest is carbohydrate accumulation and remobilisation. This study assessed the genetic basis of aspects of yield and flag leaf sugar contents under drought and well-watered conditions using mapping in a population of 90 doubled haploid lines derived from the cross Chinese Spring × SQ1. As well as soluble sugar content, glucose, fructose, sucrose, and maltose, the traits grain yield (Yld), biomass (Bio), and thousand grain weight (TGW) were also analysed. Analysis of variance showed that genotype, environment and their interactions significantly influenced all the traits studied, with environmental effects explaining up to 74.4% of the total variation. analysis identified 40 for Yld, TGW, and Bio as well as 53 for soluble carbohydrates, accounting for up to 40% of phenotypic variation. coincident for more than one trait were identified on 21 chromosome regions, associated with carbohydrate metabolism and yield performance under drought, particularly on chromosomes 2D, 4A, 4B, 5B, 5D, 6B, and 7A. Candidate genes for several yield-related were identified. These results provide useful genetic markers for the development of more drought-resistant wheat cultivars.