小麦籽粒阿魏酰阿拉伯木聚糖含量QTL定位

QTL Mapping of Ferulic Acid Arabinoxylan Content in Wheat Grain

阿拉伯木聚糖(arabinoxylan,AX)是小麦中重要的膳食纤维组分,对面制品加工品质和营养品质有重要影响。阿魏酰阿拉伯木聚糖(ferulic acid arabiaxylan,FAX)含量是决定小麦AX质量的关键因素。挖掘小麦中FAX含量相关的QTL位点及紧密连锁标记,可为FAX基因的克隆及功能标记开发提供参考。本研究选用小麦藁城8901/周麦16重组自交系(recombinant inbred line,RIL)群体结合90K SNP芯片,应用复合区间作图法(composite interval mapping,CIM),对小麦籽粒FAX含量进行QTL定位。在小麦全基因组范围内共检测到5个在多个环境下稳定存在的QTL,位于2AS、2BS、2DL、3AS和6AS染色体,分别命名为QFax.xjau-2AS、QFax.xjau-2BS、QFax.xjau-2DL、QFax.xjau-3AS和QFax.xjau-6AS.2,单个QTL可解释6.2%~18.2%的表型变异。其中QFax.xjau-3AS解释表型变异最大(18.2%)。QFax.xjau-2AS、QFax.xjau-3AS和QFax.xjau-6AS的优异等位基因来源于周麦16,QFax.xjau-2BS和QFax.xjau-2DL的优异等位基因来源于藁城8901。本研究发现的5个与FAX含量相关的稳定QTL,其紧密连锁标记可以用于高FAX含量MAS育种,为小麦FAX含量遗传解析提供参考。

Arabinoxylan （AX） is an important dietary fiber component in wheat, which has an important influence on processing and nutritional quality of flour products. Ferulic acid Arabiaxylan （FAX） content is the key factor to determine the quality of wheat AX. QTL loci related to the content of FAX in wheat and their closely linked markers could be used as a reference for cloning and development of functional markers of FAX gene. In the study, a recombinant inbred line （RIL） population derived from a Gaocheng8901/Zhoumai16 cross grown in two environments, combining with the wheat 90K SNP chip, was examined for FAX content in wheat grains by quantitative trait loci （QTL） mapping and composite interval mapping （CIM）. Five stable QTLs for FAX content were identified on chromosomes 2AS, 2BS, 2DL, 3AS and 6AS in the wheat genome, named as QFax.xjau 2AS, QFax.xjau-2BS, QFcax.xjau-2DL, QFax.xjau-3AS and QFax.xjau-6AS. Each QTL could explain the phenotypic variance of 6.2% -18.2%. QFax.xjau-3AS had the largest phenotypic variation （18.2%）. The favorable alleles of QFax.xjau-2AS,QFax.xjau-3AS and QFax.xjau-6AS were derived from Zhoumail6, the favorable alleles of QFax.xjau-2BS and QFax.xjau-2DL were derived from Gaocheng8901. Five stable QTLs for FAX content were identified whose closely linked markers could be used for breeding MAS of high FAX content and providing a reference for the genetic analysis of FAX content in wheat.