小麦高密度遗传图谱构建及抗旱相关生理性状的遗传解析

Genetic Map Construction and Genetic Dissection of DroughtTolerant Related Physiological Traits in Wheat

生理调控是小麦应对干旱胁迫的主要途径,解析小麦抗旱相关生理性状的遗传基础,发掘利用分子标记将为小麦抗旱性的高效改良提供有力支撑。本研究以加倍单倍体(DH)群体(旱选10号×鲁麦14)的150个株系为材料,利用小麦660K SNP芯片及SSR标记构建高密度遗传图谱,解析不同水分环境下孕穗期及灌浆中期小麦冠层温度(CT)、叶绿素含量(SPAD value)和植被覆盖指数(NDVI)的遗传基础。遗传图谱覆盖小麦21条染色体,分为30个连锁群,总长度4082.44 c M,标记间平均距离为2.20 c M。共检测到抗旱相关生理性状QTL 86个,分布于除3D以外的20条染色体上。冠层温度、叶绿素含量和植被覆盖指数的QTL数目分别为30、40和34个;17个QTL具有一因多效性,其中4个QTL与冠层温度和植被覆盖指数相关,8个QTL与冠层温度和叶绿素含量相关,7个QTL与叶绿素含量和植被覆盖指数相关,位于4D染色体的QPT52与3种性状均相关。本研究为小麦抗旱基因挖掘及分子育种提供了参考信息和技术支撑。

Physiological regulation is an essential way against drought stress in common wheat;dissecting the genetic basis of drought-tolerant related physiological traits, and developing molecular markers can provide strong support for efficient improvement of drought tolerance in wheat. In this study, 150 doubled haploid （DH） lines derived from a cross of Hanxuan 10 × Lumai 14 were genotyped by Wheat 660K SNP Array and SSR （ simple sequence repeat） markers for constructing a high density genetic map. The genetic basis of canopy tem- perature（CT） ,chlorophyll content（ SPAD value）and normalized difference vegetation index（NDVI） under different water regimes at booting and mid-grain fill stages were dissected. A genetic map covering 21 chromosomes was con- structed,which included 30 linkage groups and spanned 4082.44 cM, with an average interval distance of 2. 20 cM. Eighty-six QTL were identified on all chromosomes except for 3D. The numbers of QTL for CT, SPAD value and NDVI are 30,40 and 34 ,respectively. Seventeen QTL showed pleiotropic effects ,among which ,four were related to CT and NDVI, eight for CT and SPAD value, seven for SPAD value and NDVI. QPT52 located on chromosome 4D was re- lated to all three physiological traits. The present study provided reference information and technical supports for drought-tolerant gene discovery and molecular breeding in wheat.