Selection for increased water soluble carbohydrate concentration in wheat

Water soluble carbohydrate concentration in stem bases has been shown to contribute to stability of grain yield of wheat under terminal water deficit. Initial studies have indicated moderate broad sense heritability, however marker assisted selection could facilitate greater genetic gain for this complex trait.Water soluble carbohydrate is subject to the dynamics of supply from photosynthesis and demand from maturing grains and other sinks, but is also influenced by phenology, plant size, stem diameter, and canopy senescence, under the influence of declining water availability during grain fill. This study examined genetic contributions to expression of water soluble carbohydrate concentration, and its relationship to yield expression in contrasting conditions, using GÃ'E, and investigated the application of GWAS and genomic selection to genetic improvement.GÃ'E expression was complex, though it was possible to interpret sequentially via consideration of yield component expression. As expected, GWAS did not identify any major loci explaining substantial genetic variance. Genomic prediction models provided a robust whole genome analysis which assisted understanding of genetic control of this complex trait.The results are discussed in terms of refinement of breeding strategies for wheat cultivars with improvedcapacity to tolerate terminal water deficit with greater yield stability.