Genome-wide association study and quantitative trait loci mapping of seed dormancy in common wheat (Triticum aestivum L.).

Affiliation

Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, China. [Email]

Abstract

UNASSIGNED : Totally, 23 and 26 loci for the first count germination ratio and the final germination ratio were detected by quantitative trait loci (QTL) mapping and association mapping, respectively, which could be used to facilitate wheat pre-harvest sprouting breeding. Weak dormancy can cause pre-harvest sprouting in seeds of common wheat which significantly reduces grain yield. In this study, both quantitative trait loci (QTL) mapping and genome-wide association study (GWAS) were used to identify loci controlling seed dormancy. The analyses were based on a recombinant inbred line population derived from Zhou 8425B/Chinese Spring cross and 166 common wheat accessions. Inclusive composite interval mapping detected 8 QTL, while 45 loci were identified in the 166 wheat accessions by GWAS. Among these, four loci (Qbifcgr.cas-3AS/Qfcgr.cas-3AS, Qbifcgr.cas-6AL.1/Qfcgr.cas-6AL.1, Qbifcgr.cas-7BL.2/Qfcgr.cas-7BL.2, and Qbigr.cas-3DL/Qgr.cas-3DL) were detected in both QTL mapping and GWAS. In addition, 41 loci co-located with QTL reported previously, whereas 8 loci (Qfcgr.cas-5AL, Qfcgr.cas-6DS, Qfcgr.cas-7AS, Qgr.cas-3DS.1, Qgr.cas-3DS.2, Qbigr.cas-3DL/Qgr.cas-3DL, Qgr.cas-4B, and Qgr.cas-5A) were likely to be new. Linear regression showed the first count germination ratio or the final germination ratio reduced while multiple favorable alleles increased. It is suggested that QTL pyramiding was effective to reduce pre-harvest sprouting risk. This study could enrich the research on pre-harvest sprouting and provide valuable information of marker exploration for wheat breeding programs.

Keywords

90K SNP array,Dormancy,Genome-wide association study (GWAS),Pre-harvest sprouting,Quantitative trait loci (QTL) mapping,