Genetic Analysis of QTL Mapping for Developmental Behaviors of Plant Height and QTL × Water Regimes Interactions in Wheat(Triticum aestivum L.) | 小麦株高发育动态QTL定位及其与水分环境互作遗传分析

chinois. 株高是影响小麦产量的重要农艺性状，对生境水分极为敏感。为探讨小麦不同发育时期株高数量性状遗传与水分环境互作，本研究利用抗旱性强的冬小麦(Triticum aestivum L.)品种陇鉴19与水地高产品种Q9086杂交，重组近交系( RIL)群体120个株系为供试材料，测定两试验环境(甘肃镇远和兰州)雨养(干旱胁迫, DS)和灌溉条件下不同发育时期株高，采用条件复合区间作图法进行株高发育动态数量遗传位点(quantitative trait loci, QTL)分析。共检测到26个条件加性QTL(A-QTL)和56对上位性QTL(AA-QTL)。在A-QTL中，Qph.acs-1A-1、Qph.acs-4B-2、Qph.acs-5A-1、Qph.acs-5D-1、Qph.acs-6B-2和Qph.acs-7D-1在开花期前能重复表达，且有相对较高的贡献率(H2(A))(7.39%~31.04%)。AA-QTL主要由非显著加性效应的位点间互作形成，贡献率(H2(AA))在1.38~24.27%之间，这些AA-QTL效应对后期株高有显著影响。有61.54%的A-QTL和58.93%的AA-QTL分别参与了水分环境互作，在雨养条件下普遍具有降低株高的效应。条件A-QTL的加性效应在拔节期最大，随后逐渐降低，更多的体现出上位性效应。说明控制小麦株高发育的数量性状基因易与水分环境发生互作，且在小麦不同发育阶段有不同的时空表达模式。本研究结果可为小麦抗旱遗传研究与分子改良提供基础资料。

anglais. Plant height is one of important agronomy traits affecting wheat yield with very high sensitivity of water environment. Known better the quantitative genetic and its interactions with water environments of plant height (PH) development in common wheat, conditional quantitative trait loci (QTLs) were studied for PH using a recombinant inbred lines (RIL) with 120 progeny lines, derived from a cross between Longjian 19 (drought tolerant) and Q9086(water sensitive)(Triticum aestivum L.). The PH phenotypes at different stages were evaluated under rainfed (drought stress, DS) and well-watered (WW) conditions in Zhenyuan and Lanzhou, Gansu Province, respectively. Conditional QTLs analyses were performed by a mixed linear model approach. The total of 26 additive QTLs (A-QTLs) and 56 pairs of epistatic QTLs (AA-QTLs) were detected for conditional PH of wheat at different growth stages in two locations. In all A-QTLs, six major loci, Qph.acs-1A-1, Qph.acs-4B-2, Qph.acs-5A-1, Qph.acs-5D-1, Qph.acs-6B-2 and Qph.acs-7D-1, were identified in repetition at pre-flowering stages, showed higher genetic contribution percentage (H2(A)) ranged from 7.39% to 31.04%. All of AA-QTLs for PH were mainly composed of interactions between different QTLs with non-significantly additive effects, explaining H2(AA) ranged from 1.38% to 24.27%. Those AA-QTLs significantly influenced the PH at later growth stages. 61.54% of A-QTLs and 58.93% of AA-QTLs were greatly interacted with water regimes. Under rainfed, genetic effects of water environmental interaction could decrease the PH. At the jointing stage, additive effects of conditional A-QTLs for PH showed higher than that of other stages. And then, additive effects were gradually decreased but more emphasized of epistatic effects. The result indicated that quantitative genes controlled the PH development could be easily interacted with water environments, proceeding to some temporal-spatial expressions at different growth stages in wheat. The information in this study can be useful for the molecular genetic improvement of drought tolerance in wheat.