|Kolb, F. L.|
Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/11/2007
Publication Date: 12/10/2007
Citation: Yu, J., Bai, G., Zhou, W., Dong, Y., Kolb, F. 2007. Quantitative Trait Loci for Fusarium Head Blight Resistance in Chinese Wheat Landrace Wangshuibai. Phytopathology.98:87-94 Interpretive Summary: Fusarium head blight (FHB) in wheat, also called head scab, can significantly reduce both grain yield and quality of wheat. Growing FHB resistant cultivars can significantly reduce the disease losses. Wangshuibai is a Chinese landrace that has a high level of FHB-resistance. To understand the genetic mechanism of FHB resistance in Wangshuibai, genetic factors that control FHB resistance were investigated using molecular markers. We identified 5 genetic factors for resistance to initial fungal infection (type I), and 7 factors each for resistance to spread within a spike (type II) and for low deoxynivalenol (a mycotoxin produced by the pathogen) accumulation in infected grain (type III). Type I resistance was less stable than type II and type III resistance. Currently used FHB resistance sources are mainly from Sumai and its derivatives, so resistance in Wangshuibai has the potential to supplement currently used resistances.
Technical Abstract: Fusarium head blight (FHB), caused by Fusarium graminearum, can significantly reduce both grain yield and quality of wheat. Growing FHB resistant cultivars is an effective means to reduce the losses caused by the disease. Currently used FHB resistance sources are mainly Sumai 3 and its derivatives. Use of FHB resistance sources other than Sumai 3 may enrich the genetic diversity of FHB resistance sources. Wangshuibai is an FHB-resistant Chinese landrace unrelated to Sumai 3. To map quantitative trait loci (QTLs) for resistance to initial infection (type I), FHB symptoms spread within a spike (type II), and deoxynivalenol accumulation in infected grain, 139 F6 derived recombinant inbred lines (RILs) were developed from a cross between Wangshuibai and an FHB-susceptible cultivar, Wheaton. More than 1300 simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers were analyzed in this population. The broad-sense heritabilities were low for type I resistance (0.36), but high for type II resistance (0.75), and for low DON content (0.71). Five QTLs for type I resistance were detected, on chromosomes 3BS, 4B, 5DL, 3AS, and 5AS; seven QTLs for type II resistance were located, on chromosomes 3BS, 1A, 5AS, 5DL, 7AL, and 3DL; and seven QTLs for low DON content were detected, on chromosomes 3BS, 5AS, 1A, 5DL, 1BL, and 7AL. These QTLs jointly explained up to 31.7%, 64%, and 52.8% of the phenotypic variation for the three types of FHB resistance, respectively. The QTLs on the distal end of 3BS, 5AS and 5DL contributed to all three types of resistance. Two QTLs, on 7AL and 1A, as well as one QTL near the centromere of 3BS (3BSc) showed effects on both type II resistance and low DON content. The result suggested that selection for type II resistance may simultaneously improve type I resistance and lower DON content as well. The QTLs for FHB resistance identified in Wangshuibai have potential to be used to pyramid FHB resistance QTLs from different sources.