Genome-wide association study of pre-harvest sprouting traits in wheat.

To understand the genetic mechanism of wheat pre-harvest sprouting (PHS) in wheat breeding, it is significant to explore marker loci and candidate genes associated with PHS resistance using intact spikes. In this study, a total of 207 wheat varieties (lines) from China and 16,686 SNP markers were analyzed in wheat whole genome. The mixed liner model (Q + K) was used to analyze PHS phenotypic data in three environments. Genome-wide association study showed that there were abundant phenotypic variations in different environments and wheat varieties (lines). The coefficient of variation was 0.34 and 0.25, the polymorphic information content of value (PIC) was from 0.01 to 0.38, and the attenuation distance of whole genome LD was 3 Mb. The population structure and principal component analysis revealed that 207 wheat varieties (lines) could be divided into three subgroups. GWAS results indicated that 34 SNP markers were detected, which were significantly associated with pre-harvest sprouting at P < 0.001. They were located on chromosomes 3A, 3B, 4A, 4B, 5D, 6A, 6B, 6D, 7B, and 7D, and each explained 5.55%-11.63% of phenotypic variation. There were 16 markers loci detected in more than two environments, and the marker Np_Ex_c14101_22,012,676 on 6B chromosome detected in E1, E2, and average environment. Meanwhile, 13 candidate genes were screened out by mining association loci with large phenotypic effect value and stable inheritance. TraesCS3A01G589400LC, TraesCS6B01G138600/TraesCS6B01G516700LC/TraesCS6B01G548900LC, TraesCS6D01G103600, and TraesCS7B01G200100 could affect seed dormancy by regulating the sensitivity of endogenous ABA in plants. The F-box proteins were encoded by TraesCS3B01G415900LC, TraesCS6A01G144700LC, and TraesCS6B01G294800, which played major roles in plant hormone signal transduction, light signal transduction, and flower organ development. TraesCS6A01G108800, TraesCS6B01G138200/TraesCS6B01G293700 encoded Myb transcription factor family. These candidate genes are important genes related to wheat sprouting. [ABSTRACT FROM AUTHOR]