384个面包小麦基因型研究：定位7个可溶性阿拉伯木聚糖位点 遗传力约0.67
《科学报告》11月14日发表的一项全基因组关联研究揭示了面包小麦可溶性阿拉伯木聚糖纤维的遗传结构。研究由 Alabdullah、Kosik、Leverington-Waite 等人完成，论文于8月12日投稿、10月30日被接受。
阿拉伯木聚糖（AX）是小麦淀粉胚乳中主要的纤维成分，其中水提取级分（WE-AX）对健康尤其有益。研究团队组建了由384个西欧商业育种计划的现代优良小麦基因型组成的「优良纤维 panel」，在英国两个田间环境中测定全麦粉的 WE-AX 含量，作为白面粉中可溶性 AX 的替代指标。
全麦 WE-AX 表现出显著的数量变异，基因型均值基础上的广义遗传力约为0.67，两个地点之间的相关性为中等正相关（r = 0.51）。研究使用6,791个单核苷酸多态性（SNP）进行关联分析，共定位到7个与 WE-AX 含量相关的位点。
效应最强、最稳定的位点位于1B和6B染色体上，此前已被报道与 AX 调控有关；效应较小、有时依赖环境的位点位于3A、5B和7A染色体。携带更多有利等位基因的基因型，其 WE-AX 均值普遍更高。作者表示，这些已在优良种质中分离的有利等位基因，可作为培育可溶性膳食纤维含量更高小麦的潜在目标。
384 Bread Wheat Genotypes: Seven Loci for Soluble Arabinoxylan Found, Heritability About 0.67
A genome-wide association study published in Scientific Reports on November 14 reveals the genetic architecture of soluble arabinoxylan fibre in bread wheat. The work, by Alabdullah, Kosik, Leverington-Waite and colleagues, was received on August 12 and accepted on October 30.
Arabinoxylan (AX) is the dominant fibre component in wheat starchy endosperm, and its water-extractable fraction (WE-AX) is particularly beneficial to health. The team assembled an Elite Fibre Panel of 384 elite modern wheat genotypes from Western European commercial breeding programmes, and quantified WE-AX in wholemeal, as a proxy for soluble AX in white flour, across two UK field environments.
Wholemeal WE-AX showed substantial quantitative variation, with a broad-sense heritability of about 0.67 on a genotype-mean basis and a moderate positive correlation between sites (r = 0.51). Association analyses using 6,791 single nucleotide polymorphisms (SNPs) identified seven loci associated with WE-AX content.
The strongest and most stable effects mapped to major loci on chromosomes 1B and 6B, previously implicated in AX regulation, while additional loci of smaller and sometimes environment-dependent effect were detected on chromosomes 3A, 5B and 7A. Genotypes carrying more favourable alleles generally had higher mean WE-AX. The authors said the favourable alleles already segregating within elite germplasm are potential targets for breeding wheat with enhanced soluble dietary fibre.
来源：《科学报告》
发布：GSM·美国（发布链接）
图片来源：图：一片面包小麦（Triticum aestivum）田。作者：Teknad，CC0，维基共享资源。 / Photo: A bread wheat (Triticum aestivum) field. Credit: Teknad, CC0, via Wikimedia Commons.
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