QTL mapping of kernel oil concentration with high-oil maize by SSR markers.

摘要

High-oil maize as a value added crop has received increased interest recently. In this study, quantitative trait loci (QTL) and their genetic effects influencing kernel oil concentration were investigated using Beijing High Oil (BHO) germplasm. An F2 population with 450 individuals was derived from a cross between a high-oil inbred By804 selected from a high-oil population (BHO Cycle 13) and an important normal inbred B73. The single kernel oil concentration of F2 and F3 seeds was determined using NMR (Nuclear Magnetic Resonance). 150 co-dominant SSR markers were selected to construct a genetic linkage map, 1759.1 cM (centimorgan distance) long with an average interval of 11.65 cM. In all, 20 QTL associated with kernel oil concentration were mapped in a 3-54 LOD threshold value. Six QTL were jointly detected in the F2 and F3 seeds, accounting for 30% of the total mapped QTL, while 14 QTL were detected singly. The proportion of phenotypic variation explained by a single QTL ranged from 2.31% to 17.51%. There were four QTL in both the F2 seeds and F3 seeds, accounting for more than 5% of the phenotypic variation. Most of the single QTL either with F2 or F3 seeds explained less 5% of the phenotypic variation. 35% of QTL identified in this study had identical or similar chromosomal locations to those previously identified with IHO (Illinois High Oil) germplasm. The most favorable allele, oilcl-1, detected on chromosome 1 in this study, was not the most favorable allele identified with IHO. These suggests that more diverse germplasm should be analyzed to detect additional QTL for oil concentration, or to find the more favorable alleles at common QTL.