来源于人工合成小麦的TaGW2-6A等位变异类型的鉴定及分析

Identification and Function Analysis of TaGW2-6A Allelic Variations in Synthetic Wheat

位于6A染色体上的TaGW2基因与小麦粒重呈正相关作用,在其启动子区存在Hap-6A-A和Hap-6A-G等位变异。本研究通过分析重组自交系群体(IMTI)亲本W7984和Opata中TaGW2-6A基因启动子区差异,开发特异性分子标记,并分析来源于人工合成小麦的TaGW2-6A等位变异不同倍性小麦品种中的分布及其对千粒重的影响。结果表明:与普通小麦Opata相比,人工合成小麦W7984启动子区存在7个碱基插入。利用特异性分子标记TaGW2-6Asp可以将来源于W7984的等位变异TaGW2-6Aw和来源于Opata的等位变异TaGW2-6Ao明显区分。在14份二倍体,24份四倍体和24份人工合成小麦中仅存在TaGW2-6Aw等位变异。在重组自交系中两种等位变异的千粒重差异不明显,而在青海省育成品种中TaGW2-6Aw的千粒重平均值高于TaGW2-6Ao,并且差异显著。说明从人工合成小麦中筛选出的TaGW2-6Aw是优异等位变异,可运用于小麦高产品种的选育过程。

TaGW2-6A on chromosome 6A have a positive effect on thousand-grain weight.There were two SNPs（Hap-6A-A and Hap-6A-G） in the promoter region.In this study,the promoter regions of TaGW2-6A gene promoter differences in W7984 and Opata of recombinant inbred lines（IMTI） population was analyzed to develop a specific molecular markers.Then the distribution of TaGW2-6A allelic variations derived from synthetic hexaploid wheat in different ploidy wheat varieties was detected and the effects of TaGW2-6A allelic variations on thousand-grain weight was analyzed.The results showed that there were 7 nucleotides inserted in the W7984 promoter region of synthetic wheat compared with common wheat Opata.The TaGW2-6Aw allelic variation derived from W7984 and the TaGW2-6Ao allelic variation derived from Opata could be clearly distinguished by using the specific molecular marker TaGW2-6Asp.There only existed the TaGW2-6Aw allelic variation in 14 diploid,24 tetraploid and 24 artificially synthesized hexaploid wheats.The average of thousand-grain weight of two allelic variations was not significant in IMTI population.However,the average of thousand-grain weight in TaGW2-6Aw was higher than that with TaGW2-6Ao in breeding cultivars derived from Qinghai province withsignificant difference.Results suggested that TaGW2-6Aw derived from synthetic hexaploid wheat might be a good allelic variation and could be used for breeding high yield cultivars.