Quantitative trait loci for water-soluble carbohydrates and associations with agronomic traits in wheat

• DOI: 10.1071/ar08067
• Publication Date: 2008-09-18T06:47:06Z
• Authors: G. J. Rebetzke; A. F. van Herwaarden; C. Jenkins; M. Weiss; D. Lewis; S. Ruuska; L. Tabe; N. A. Fettell; R. A. Richards
• Keywords: Anthesis; Trait; Transgressive segregation

Several environmental factors including drought and disease can reduce leaf area photosynthesis during grain-filling to decrease grain yield kernel weight of cereal crops. Water-soluble carbohydrates (WSC) accumulated around anthesis be mobilised assist in filling developing grains when post-anthesis assimilation is low. Cultivar differences support opportunities select for high WSC but little known the extent or nature genetic control this trait wheat. Three wheat mapping populations (Cranbrook/Halberd, Sunco/Tasman, CD87/Katepwa) were phenotyped other agronomic traits across multiple environments. The range concentration (WSC-C) was large among progeny contributing moderate-to-high narrow-sense heritabilities within environments (h2 = 0.51–0.77). Modest genotype × environment interaction reduced correlation means (rp 0.37–0.78, P < 0.01) heritability on a line-mean 0.55–0.87) basis. Transgressive segregation complex, with 7–16 QTLs being identified WSC-C each population. Heritability smaller 0.32–0.54) mass per unit (WSC-A), reflecting residual variance estimating biomass. Fewer significant (4–8) population, while sizes individual effects varied between repeatable genomic regions common those associated plant height (e.g. Rht-B1) and/or date Ppd1). Genotypes commonly shorter, flowered earlier, produced significantly (P fewer tillers than low WSC-C. This resulted similar yields, lower final biomass, m2, greater dry partitioning grain, weight, less screenings compared genotypes. By contrast, lines WSC-A more fertile maturity number, yield, yet size genotypes WSC-A. data an important role assuring stable size. However, small many independent may limit their direct use marker-aided selection breeding programs. We suggest using molecular markers enrich favourable alleles before costly phenotypic partially inbred families