冬小麦低温处理叶片细胞膜透性的QTL定位

Mapping QTL for Cell Membrane Permeability of Leaf Treated by Low Temperature in Winter Wheat

为探索冬小麦抗寒性的分子机制,以168个花培3号×豫麦57的双单倍体株系为作图群体,利用已构建含有324个SSR标记的遗传图谱,对电导法测定低温(-18℃)处理后的叶片膜透性进行QTL定位。利用完全区间作图法,在3种环境下共检测到21个与叶片膜透性相关的加性QTLs,分布于1B、2A、3A、3B、5B、6A、6B、6D、7B和7D染色体上,其中4个位点(qCMP-1B-1、qCMP-3B-2、qCMP-5B-1和qCMP-5B-4)遗传贡献率大于10%,属主效基因,其余QTL的遗传贡献率较小,属微效基因。3种环境条件下在5B染色体的Xgwm213-Xswes861.2区间检测到共同位点,与Xswes861.2的遗传距离为0cM,其中qCMP-5B-1(环境1)和qCMP-5B-4(环境3)的贡献率高达17.5%和14.0%。研究结果对于小麦抗寒标记选择和抗寒育种具有应用价值。

To understand the genetic mechanism of cold resistance in winter wheat, we mapped quantitative trait loci （QTLs） for cell membrane permeability of leaf treated by low temperature using compound interval method based on an existing linkage map containing 324 simple sequence repeat （SSR） markers. The map population, which was consisted of 168 double haploid lines from the cross Huapei 3 x Yumai 57, was planted in three sites, and the cell membrane permeability of leaf treated by low temperature （-18℃） was determined with electric conductometry. A total of 21 additive QTLs associated with cell membrane permeability of leaf were detected in three environments, which were distributed on chromosomes 1B, 2A, 3A, 3B, 5B, 6A, 6B, 6D, 7B, and 7D. Four loci （qCMP-1B-1, qCMP-3B-2, qCMP-5B-1, and qCMP-5B-4） with phenotypic contributions higher than 10% were re- garded as major genes, and the remaining QTLs were minor genes with phenotypic contributions lower than 10%. A common locus in the Xgwm213-Xswes861.2 interval on chromosome 5B was detected in the three environments, with 0 cM genetic dis- tance from Xswes861.2. The loci, designated qCMP-5B-1 in environment 1 and qCMP-5B-4 in environment 3, explained 17.5% and 14.0% with phenotypic variations, respectively. The result of the present study was useful for marker-assisted selection and breeding for cold resistance of wheat.