Mapping the Genes Controlling Inulin Content in Wheat
As a widely consumed staple food, wheat (Triticum aestivum) is a good vehicle for inulin, a complex carbohydrate which improves gastrointestinal microfauna populations thereby increasing the body’s ability to take up micronutrients and improving the immune system. This set of studies was conducted to determine the amount of variation for inulin content in wheat, the trait’s heritability and the level of environmental effects on this trait, and to find quantitative trait loci for inulin content. Amongst 87 varieties, inulin content ranged from 0.04% to 1.46% of dry weight with a median value of 0.70%, demonstrating that there is significant genetic variation for inulin content. When 20 varieties were grown in 6 different locations, inulin content was found to have a low heritability (H2=0.198999), and GxE effects were a significant factor in predicting inulin content. From a population consisting of 101 doubled-haploid lines created from a cross between AC Reed and Grandin, composite interval mapping detected major QTLs on chromosomes 2BL-2 and 5BS which explained 20.15% and 15.28% of the variation for inulin content, respectively. The results of these studies indicate that, although the heritability is relatively low, there is sufficient genetic variation for improving inulin content in a wheat breeding program and that marker-assisted selection would be useful.