Edzesi Wisdom M, Dang Xiaojing, Liang Lijun, Liu Erbao, Zaid Imdad U, Hong Delin
State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University Nanjing, China.
Front Plant Sci. 2016 Jun 7;7:787. doi: 10.3389/fpls.2016.00787. eCollection 2016.
Mining elite alleles for grain size and weight is of importance for the improvement of cultivated rice and selection for market demand. In this study, association mapping for grain traits was performed on a selected sample of 628 rice cultivars using 262 SSRs. Grain traits were evaluated by grain length (GL), grain width (GW), grain thickness (GT), grain length to width ratio (GL/GW), and 1000-grain weight (TGW) in 2013 and 2014. Our result showed abundant phenotypic and genetic diversities found in the studied population. In total, 2953 alleles were detected with an average of 11.3 alleles per locus. The population was divided into seven subpopulations and the levels of linkage disequilibrium (LD) ranged from 34 to 84 cM. Genome-wide association mapping detected 10 marker trait association (MTAs) loci for GL, 1MTAs locus for GW, 7 MTAs loci for GT, 3 MTAs loci for GL/GW, and 1 MTAs locus for TGW. Twenty-nine, 2, 10, 5, and 3 elite alleles were found for the GL, GW, GT, GL/GW, and TGW, respectively. Optimal cross designs were predicted for improving the target traits. The accessions containing elite alleles for grain traits mined in this study could be used for breeding rice cultivars and cloning the candidate genes.
挖掘控制水稻粒型和粒重的优良等位基因对于改良栽培稻以及满足市场需求的品种选育具有重要意义。本研究利用262个SSR标记，对628份水稻品种组成的样本进行了粒型性状的关联分析。于2013年和2014年对粒长（GL）、粒宽（GW）、粒厚（GT）、长宽比（GL/GW）和千粒重（TGW）等粒型性状进行了评价。结果表明，供试群体具有丰富的表型和遗传多样性。共检测到2953个等位基因，每个位点平均有11.3个等位基因。群体被划分为7个亚群，连锁不平衡（LD）水平范围为34至84 cM。全基因组关联分析检测到10个与粒长相关的标记-性状关联（MTA）位点、1个与粒宽相关的MTA位点、7个与粒厚相关的MTA位点、3个与长宽比相关的MTA位点和1个与千粒重相关的MTA位点。分别在粒长、粒宽、粒厚、长宽比和千粒重中发现了29个、2个、10个、5个和3个优良等位基因。预测了改良目标性状的最佳杂交设计。本研究中挖掘到的含有粒型性状优良等位基因的材料可用于水稻品种选育和候选基因克隆。
