Genome-Wide Association Study of Grain Architecture in Wild Wheat Aegilops tauschii.
Genome-Wide Association Study of Grain Architecture in Wild Wheat Aegilops tauschii.
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DOI：
10.3389/fpls.2017.00886
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发表时间：
2017
影响因子：
5.6
通讯作者：
Chhuneja P
中科院分区：
文献类型：
--
作者：
Arora S;Singh N;Kaur S;Bains NS;Uauy C;Poland J;Chhuneja P
节节麦(Aegilopstauschii)是普通小麦的D-基因组祖先，在产量、生物和非生物胁迫耐受性、品质和营养等具有潜在经济意义的性状上具有巨大的多样性。在本研究中，Ae.采用全基因组关联研究方法，对节节草种质资源进行了研究，并对其遗传基础进行了剖析。谷物的长度、宽度和重量以177 Ae为单位。3年生的狗尾草种质呈近似正态分布，变异分别为1.74、1.75和2.82倍。利用测序基因分型(GBS)方法对这些品系进行了遗传特征分析，产生了11,489个单核苷酸多态(SNP)标记。遗传多样性分析表明，Ae中存在两个不同的亚群(命名为谱系1和2)。陶斯奇。在GBS标记的基础上，利用114个非冗余材料和5,249个SNP标记进行了遗传相似性计算。共有17个与籽粒大小性状相关的SNPs分布在所有7条染色体上，其中6D、5D和2D具有最显著的标记-性状关联。其中6D_66.4~71.1 cM、1D_143.5~156.7 cM、2D_89.9~92.5 cM等区域与多个性状相关。在一些相关的SNP标记中，确定了与细胞分裂和分化相关的候选基因。进一步验证这些基因座将有助于理解它们在决定当前种质的籽粒大小和等位基因多样性中的作用，以及它们在转移到面包小麦背景下对籽粒大小的影响。
Aegilops tauschii, the D-genome progenitor of Triticum aestivum, encompasses huge diversity for various traits of potential economic importance such as yield, biotic and abiotic stress tolerance, quality and nutrition. In the present study, variation for grain size in Ae. tauschii germplasm was studied and its genetic basis dissected using genome-wide association study (GWAS). Grain length, width, and weight evaluated in 177 Ae. tauschii accessions over 3 years showed near normal distribution with 1.74-, 1.75-, and 2.82-fold variation, respectively. These lines were genetically characterized using genotyping-by-sequencing (GBS) protocol that produced 11,489 single nucleotide polymorphic (SNP) markers. Genetic diversity analysis revealed the presence of two distinct subgroups (designated as lineage 1 and 2) in Ae. tauschii. Based on GBS markers, the genetic similarity was calculated between the accessions and GWAS was conducted using 114 non-redundant accessions and 5,249 SNP markers. A total of 17 SNPs associated with grain size traits distributed over all the seven chromosomes were revealed with 6D, 5D, and 2D harboring most significant marker–trait associations. Some of the chromosomal regions such as 6D_66.4–71.1 cM, 1D_143.5–156.7 cM, and 2D_89.9–92.5 cM had associations with multiple traits. Candidate genes associated with cell division and differentiation were identified for some of the associated SNP markers. Further efforts to validate these loci will help to understand their role in determining grain size and allelic diversity in current germplasm and its effect on grain size upon transfer to bread wheat background.