Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstr 3, 06466, Gatersleben, Germany.
Theor Appl Genet. 2012 Aug;125(3):561-75. doi: 10.1007/s00122-012-1853-3. Epub 2012 Apr 5.
High temperature (>30 °C) at the time of grain filling is one of the major causes of yield reduction in wheat in many parts of the world, especially in tropical countries. To identify quantitative trait loci (QTL) for heat tolerance under terminal heat stress, a set of 148 recombinant inbred lines was developed by crossing a heat-tolerant hexaploid wheat (Triticum aestivum L.) cultivar (NW1014) and a heat-susceptible (HUW468) cultivar. The F(5), F(6), and F(7) generations were evaluated in two different sowing dates under field conditions for 2 years. Using the trait values from controlled and stressed trials, four different traits (1) heat susceptibility index (HSI) of thousand grain weight (HSITGW); (2) HSI of grain fill duration (HSIGFD); (3) HSI of grain yield (HSIYLD); and (4) canopy temperature depression (CTD) were used to determine heat tolerance. Days to maturity was also investigated. A linkage map comprising 160 simple sequence repeat markers was prepared covering the whole genome of wheat. Using composite interval mapping, significant genomic regions on 2B, 7B and 7D were found to be associated with heat tolerance. Of these, two (2B and 7B) were co-localized QTL and explained more than 15 % phenotypic variation for HSITGW, HSIGFD and CTD. In pooled analysis over three trials, QTL explained phenotypic variation ranging from 9.78 to 20.34 %. No QTL × trial interaction was detected for the identified QTL. The three major QTL obtained can be used in marker-assisted selection for heat stress in wheat.
高温（>30°C）在籽粒灌浆期是世界上许多地区，尤其是热带国家小麦减产的主要原因之一。为了鉴定耐热性在高温胁迫下的数量性状位点（QTL），通过杂交一个耐热性六倍体小麦（Triticum aestivum L.）品种（NW1014）和一个耐热性（HUW468）品种，开发了一组 148 个重组自交系。在田间条件下，通过两年的两个不同播种期对 F5、F6 和 F7 代进行评估。利用受控和胁迫试验的性状值，确定了四个不同的性状（1）千粒重的耐热性指数（HSITGW）；（2）灌浆持续时间的耐热性指数（HSIGFD）；（3）产量的耐热性指数（HSIYLD）；（4）冠层温度下降（CTD）来确定耐热性。还研究了成熟天数。利用复合区间作图法，在小麦全基因组上发现了与耐热性相关的 2B、7B 和 7D 上的显著基因组区域。其中，两个（2B 和 7B）被共定位 QTL，并解释了 HSITGW、HSIGFD 和 CTD 超过 15%的表型变异。在三个试验的汇总分析中，QTL 解释的表型变异范围从 9.78%到 20.34%。未检测到鉴定的 QTL 与试验之间的互作。获得的三个主要 QTL 可用于小麦耐热性的标记辅助选择。
