不同灌溉模式下小麦穗粒数QTL定位分析

为了挖掘在多水分环境中能够稳定表达的小麦穗粒数QTL，以洛旱2号和潍麦8号及其衍生的302 个F_8:9重组自交系(RIL)为材料，分别在3个干旱和3个正常灌溉模式下，对穗粒数QTL进行定位分析，结果检测到24个加性QTLs，位于16个位点，分布于2B、3A、3B、3D、4A、4B、5A、5B、6B和7B共10条染色体上，单个QTL可解释3.70%～20.43%的表型变异。在充分灌溉条件下的三个环境（E1、E2和E3）中，共有14个QTLs，11个位点被检测到；在限制水分的三个环境（E4、E5和E6）中共有10个QTLs，6个位点被检测到。在所有检测到的16个位点中，有9个位点只在灌溉环境下被检测到，有5个位点只在旱作环境下被检测到，有2个位点在灌溉和旱作环境下同时被检测到。位于3A染色体上标记Xbarc012和 Xgpw2266之间的 Qknps-WL-3A，同时在E1、E4、E5和E6环境中被检测到，其中三个环境可解释大于10%的表型变异，且在所有的旱作环境中能够稳定表达，可以作为分子标记辅助选择的候选位点，用于辅助选育节水高产小麦新品种。

QTL Mapping for Kernel Number per Spike in Wheat under Different Irrigation Modes

In order to explore genes associated with kernel number per spike(KNPS) that stably expressed in different irrigation modes , the QTLs for KNPS were evaluated by the population of 302 recombinant inbred lines(RILs) derived from a cross between a drought-tolerant cultivar Luohan 2 and a water-sensitive cultivar Weimai 8 in three restrict watering and three irrigation environments. Totally 24 additive QTLs for KNPS were identified and distributed on chromosomes 2B, 3A, 3B, 3D, 4A, 4B, 5A, 5B, 6B and 7B, respectively, explaining 3.7% to 20.43% phenotypic variations. Of them, 14 additive QTLs located at 11 sites and 10 QTLs located at 6 sites in three irrigation environments and three drought stress environments, respectively. Among all the 16 sites detected, 9 sites were detected in the irrigation environment only, and 5 sites were detected in the dry farming environment only, and 2 sites were detected in the irrigation and dry farming environments simultaneously. Qknps-WL-3A, located between Xbarc012 and Xgpw2266 on 3A chromosome, was detected in E1, E4, E5, E6, simultaneously. Besides, it can explain more than 10% phenotypic variation in three environments and can be detected in all the three water stress environments. Therefore, it can be used as a candidate marker in molecular marker assisted breeding for new water-saving and high-yielding varieties.