title: Effective marker alleles associated with type 2 resistance to Fusarium head blight infection in fields.
abstract: Molecular markers associated with known quantitative trait loci (QTLs) for type 2 resistance to Fusarium head blight (FHB) in bi-parental mapping population usually have more than two alleles in breeding populations. Therefore, understanding the association of each allele with FHB response is particularly important to marker-assisted enhancement of FHB resistance. In this paper, we evaluated FHB severities of 192 wheat accessions including landraces and commercial varieties in three field growing seasons, and genotyped this panel with 364 genome-wide informative molecular markers. Among them, 11 markers showed reproducible marker-trait association (p < 0.05) in at least two experiments using a mixed model. More than two alleles were identified per significant marker locus. These alleles were classified into favorable, unfavorable and neutral alleles according to the normalized genotypic values. The distributions of effective alleles at these loci in each wheat accession were characterized. Mean FHB severities increased with decreased number of favorable alleles at the reproducible loci. Chinese wheat landraces and Japanese accessions have more favorable alleles at the majority of the reproducible marker loci. FHB resistance levels of varieties can be greatly improved by introduction of these favorable alleles and removal of unfavorable alleles simultaneously at these QTL-linked marker loci.
authors.affiliation: Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University , Yangzhou, Jiangsu 225009 China.
authors.forename: Tao
authors.initials: T
authors.lastname: Li
authors.affiliation: Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University , Yangzhou, Jiangsu 225009 China.
authors.forename: Meng
authors.initials: M
authors.lastname: Luo
authors.affiliation: Department of Agronomy, Kansas State University , Manhattan, KS 66506 , USA.
authors.forename: Dadong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University , Yangzhou, Jiangsu 225009 China.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Jiangsu Provincial Key Laboratory of Crop Genetics and Physiology/Co-Innovation Center for Modern Production Technology of Grain Crops; Key Laboratory of Plant Functional Genomics of Ministry of Education; Wheat Research Center, Yangzhou University , Yangzhou, Jiangsu 225009 China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Agronomy, Kansas State University, Manhattan, KS 66506, USA; USDA-ARS Hard Winter Wheat Genetics Research Unit, Manhattan, KS 66506USA.
authors.forename: Guihua
authors.initials: G
authors.lastname: Bai
keywords: Fusarium head blight; allelic effects; association analysis; breeding population; molecular markers; wheat