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ARS Home » Plains Area » Manhattan, Kansas » Center for Grain and Animal Health Research » Hard Winter Wheat Genetics Research » Research » Publications at this Location » Publication #323092

Title: Single nucleotide polymorphism tightly linked to a major QTL on chromosome 7A for both kernel length and kernel weight in wheat

Author
item SU, ZHENGI - Kansas State University
item JIN, SUJUAN - Kansas State University
item YUE, LU - Kansas State University
item ZHANG, GUORONG - Kansas State University
item Chao, Shiaoman
item Bai, Guihua

Submitted to: Molecular Breeding
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2016
Publication Date: 5/5/2016
Publication URL: https://handle.nal.usda.gov/10113/63224
Citation: Su, Z., Jin, S., Yue, L., Zhang, G., Chao, S., Bai, G. 2016. Single nucleotide polymorphism tightly linked to a major QTL on chromosome 7A for both kernel length and kernel weight in wheat. Molecular Breeding. 36: 15. doi:10.1007/s11032-016-0436-4.

Interpretive Summary: Thousand-kernel weight (TKW) is one of the major components of grain yield in wheat. This study mapped a gene for high TKW on chromosome 7A of wheat cultivar ‘Clark’. This gene explained 19.7% of variation for TKW and also showed a major effect on kernel length, one of the major components of TKW. Two closely linked markers to the gene were validated in a diversity panel of 200 U.S. winter wheat accessions and converted into breeder-friendly markers that can be easily used in breeding to improve wheat TKW.

Technical Abstract: Thousand-kernel weight (TKW) is one of the major components of grain yield in wheat (Triticum aestivum). Identifying major quantitative trait loci (QTLs) for TKW and developing diagnostic markers are prerequisite for success in marker-assisted selection (MAS) to improve wheat yield through breeding. This study mapped a major QTL, designated as TaTKW-7AL, for increasing TKW on the long arm of chromosome 7A of ‘Clark’ to a 1.3 cM interval between single nucleotide polymorphism (SNP) markers IWB13913 and IWA5913. This QTL explained 19.7% of phenotypic variation for TKW. A QTL for increasing kernel length (KL), one of the major components of TKW, was mapped in the same interval as TaTKW-7AL, suggesting increased TKW by the QTL in ‘Clark’ is most likely due to the increased KL. Association analysis on a diversity panel of 200 U.S. winter wheat accessions also identified a haplotype of three SNP markers (IWB13913, IWB6693 and IWA5913) that were tightly associated with the both KL and TKW. The analysis of allele frequencies of the haplotype in the diversity panel suggested that the favored allele of TaTKW-7AL has not been strongly selected for in practice, and has potential to be used to improve grain yield in breeding. Two user-friendly flanking KASPar markers, IWB13913 and IWA5913, were developed for MAS of TaTKW-7AL.