Gahlaut Vijay, Jaiswal Vandana, Tyagi Bhudeva S, Singh Gyanendra, Sareen Sindhu, Balyan Harindra S, Gupta Pushpendra Kumar
Department of Genetics and Plant Breeding, Ch. Charan Singh University, Meerut, India.
ICAR-Indian Institute of Wheat and Barley Research, Karnal, India.
PLoS One. 2017 Aug 9;12(8):e0182857. doi: 10.1371/journal.pone.0182857. eCollection 2017.
In bread wheat, QTL interval mapping was conducted for nine important drought responsive agronomic traits. For this purpose, a doubled haploid (DH) mapping population derived from Kukri/Excalibur was grown over three years at four separate locations in India, both under irrigated and rain-fed environments. Single locus analysis using composite interval mapping (CIM) allowed detection of 98 QTL, which included 66 QTL for nine individual agronomic traits and 32 QTL, which affected drought sensitivity index (DSI) for the same nine traits. Two-locus analysis allowed detection of 19 main effect QTL (M-QTL) for four traits (days to anthesis, days to maturity, grain filling duration and thousand grain weight) and 19 pairs of epistatic QTL (E-QTL) for two traits (days to anthesis and thousand grain weight). Eight QTL were common in single locus analysis and two locus analysis. These QTL (identified both in single- and two-locus analysis) were distributed on 20 different chromosomes (except 4D). Important genomic regions on chromosomes 5A and 7A were also identified (5A carried QTL for seven traits and 7A carried QTL for six traits). Marker-assisted recurrent selection (MARS) involving pyramiding of important QTL reported in the present study, together with important QTL reported earlier, may be used for improvement of drought tolerance in wheat. In future, more closely linked markers for the QTL reported here may be developed through fine mapping, and the candidate genes may be identified and used for developing a better understanding of the genetic basis of drought tolerance in wheat.
在面包小麦中，对9个重要的干旱响应农艺性状进行了QTL区间作图。为此，以Kukri/Excalibur衍生的双单倍体（DH）作图群体在印度的4个不同地点种植了3年，种植环境包括灌溉和雨养环境。使用复合区间作图（CIM）进行的单基因座分析检测到98个QTL，其中包括针对9个个体农艺性状的66个QTL，以及针对相同9个性状的干旱敏感性指数（DSI）的32个QTL。双基因座分析检测到4个性状（抽穗天数、成熟天数、灌浆持续时间和千粒重）的19个主效QTL（M-QTL）和2个性状（抽穗天数和千粒重）的19对上位性QTL（E-QTL）。单基因座分析和双基因座分析中有8个QTL是共同的。这些QTL（在单基因座和双基因座分析中均已鉴定）分布在20条不同的染色体上（4D除外）。还鉴定出了5A和7A染色体上的重要基因组区域（5A携带7个性状的QTL，7A携带6个性状的QTL）。涉及本研究中报道的重要QTL以及先前报道的重要QTL的聚合的标记辅助轮回选择（MARS）可用于提高小麦的耐旱性。未来，可通过精细作图开发与本文报道的QTL更紧密连锁的标记，并鉴定候选基因，以更好地理解小麦耐旱性的遗传基础。
