Genome-Wide Association Study Reveals Novel Genomic Regions Associated With High Grain Protein Content in Wheat Lines Derived From Wild Emmer Wheat

Jia Liu; Lin Huang; Changquan Wang; Yaxi Liu; Zehong Yan; Zhenzhen Wang; Lan Xiang; Xiaoying Zhong; Fangyi Gong; Youliang Zheng; Dengcai Liu; Bihua Wu

doi:10.3389/fpls.2019.00464

Genome-Wide Association Study Reveals Novel Genomic Regions Associated With High Grain Protein Content in Wheat Lines Derived From Wild Emmer Wheat

Front Plant Sci. 2019 Apr 16:10:464. doi: 10.3389/fpls.2019.00464. eCollection 2019.

Authors

Jia Liu^{1

2}, Lin Huang^{1

2}, Changquan Wang³, Yaxi Liu^{1

2}, Zehong Yan^{1

2}, Zhenzhen Wang¹, Lan Xiang¹, Xiaoying Zhong¹, Fangyi Gong¹, Youliang Zheng^{1

2}, Dengcai Liu^{1

2}, Bihua Wu^{1

2}

Affiliations

¹ Triticeae Research Institute, Sichuan Agricultural University, Chengdu, China.
² Key Laboratory of Crop Genetic Resources and Improvement, Ministry of Education, Sichuan Agricultural University, Chengdu, China.
³ College of Resources, Sichuan Agricultural University, Chengdu, China.

Abstract

Grain protein content (GPC) and yield are of two important traits in wheat, but their negative correlation has hampered their simultaneous improvement in conventional breeding. Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is an important genetic resource for wheat quality improvement. In this study, we report a genome-wide association study (GWAS) using 13116 DArT-seq markers to characterize GPC in 161 wheat lines derived from wild emmer. Using a general linear model, we identified 141 markers that were significantly associated with GPC, and grouped into 48 QTL regions. Using both general linear model and mixed linear model, we identified four significant markers that were grouped into two novel QTL regions on chromosomes 2BS (QGpc.cd1-2B.1) and 7BL (QGpc.cd1-7B.2). The two QTLs have no negative effects on thousand kernel weight (TKW) and should be useful for simultaneous improvement of GPC and TKW in wheat breeding. Searches of public databases revealed 61 putative candidate/flanking genes related to GPC. The putative proteins of interest were grouped in four main categories: enzymes, kinase proteins, metal transport-related proteins, and disease resistance proteins. The linked markers and associated candidate genes provide essential information for cloning genes related to high GPC and performing marker-assisted breeding in wheat.

Keywords: GPC; GWAS; common wheat; wide hybridization; wild emmer wheat.