Mapping of QTLs for resistance to Fusarium head blight in wheat.

摘要

Fusarium head blight (FHB) of wheat, caused mainly by Fusarium graminearum Schwabe (telemorph Gibberella zeae), causes reduced yield and lowered grain quality. Identification of resistance sources and understanding the genetic basis of the resistance is beneficial to wheat breeding for FHB resistance. Two recombinant inbred wheat populations were developed by single-seed descent from the crosses ‘Ning 894037 x Alondra’ and ‘Patterson x F201R’, respectively. The phenotypic evaluation of the RI population Ning 894037 x Alondra displayed a continuous distribution with two peaks, suggesting a gene with large effect controlling the resistance coupled with some genes with relatively small effects. SSR marker analysis revealed three chromosomal regions associated with FHB resistance in this population, located on chromosomes 3B, 2D and 6B. The QTL on 3B accounted for 42.5% of the phenotypic variation. The three QTLs collectively explained 51.6% of the phenotypic variation. SSR marker analysis also provides evidence that the 3BS QTL in Sumai 3 was derived from Taiwan Wheat instead of the Italian line ‘Funo’, which was thought to be the donor of FHB resistance from previous pedigree analysis. In the RI population of Patterson x F201R, the phenotypic distribution is bell-shaped, suggesting quantitative inheritance of FHB resistance. Four chromosomal regions associated with resistance to FHB were identified in this population with SSR markers. The QTLs on chromosomes 1B and 3A have relatively large effects and accounted for 18.7% and 13.0% of the phenotypic variation, respectively. The four QTLs jointly accounted for 32.7% of phenotypic variation. The mapping results showed the genetic diversity of resistance genes in Ning 894037 and F201R, which represent the Chinese and European resistant sources, respectively. SSR markers closely linked to FHB resistance QTLs in these two parent lines may be helpful in breeding programs using marker assisted selection.