小麦TaSnRK2.10的多态性及与农艺性状的关联

Polymorphism of TaSnRK2.10 and Its Association with Yield-Related Traits in Wheat

【目的】蔗糖非发酵蛋白激酶(SnRK)是一类丝氨酸/苏氨酸蛋白激酶,在植物信号传递途径中发挥着重要作用。研究小麦TaSnRK2.10的多态性,开发其功能标记,并进行标记-表型性状关联分析,为利用分子标记进行遗传改良和种质创新提供依据。【方法】以30份多态性较高的六倍体普通小麦及其野生近缘种的二倍体和四倍体为材料,通过测序分析TaSnRK2.10-A的序列多态性;利用中国春缺-四体材料对该基因进行染色体定位;利用RIL群体(偃展1号×内乡188)对基因进行遗传定位;根据TaSnRK2.10-A序列多态性,开发分子标记,以262份普通小麦构成的自然群体为材料分析基因单倍型与表型性状的关联特性。【结果】克隆了小麦TaSnRK2.10的A、D基因组序列,在由30份多态性较高的小麦材料组成的自然群体中,没有检测到来自D基因组的TaSnRK2.10-D序列多态性;TaSnRK2.10-A全长4 688 bp,包括启动子1 934 bp、5′-UTR 343 bp、编码区2 319 bp及3′-UTR 92bp。在基因全长序列中共检测到15个SNP、2个InDel。其中,启动子区有8个SNP,5′-UTR有2个,编码区有5个。位于编码区的5个SNP中,2个存在于外显子,其中一个是非同义突变。2个InDel均位于编码区。根据序列多态性分别设计了启动子区的分子标记PM1和PM2,以及基因编码区的分子标记GM1和GM2。利用中国春缺-四体材料将TaSnRK2.10-A定位于小麦染色体4A,利用RIL群体将TaSnRK2.10-A定位在染色体4A的标记Xwpt7001和WMC48之间,与2个侧翼标记的遗传距离分别为5.1 cM和25.7 cM。利用开发的4个分子标记,将自然群体的262份材料分为4种单倍型,分别与千粒重、单株穗数和每穗小穗数显著相关或极显著相关,HapⅡ和HapⅢ是提高千粒重的优异单倍型。4 184 bp位点为C时,为高千粒重的优异等位变异。【结论】小麦TaSnRK2.10-A位于染色体4A。HapⅡ和HapⅢ是提高千粒重的优异单倍型,HapⅣ是提高单株穗数的优异单倍型,4 184 bp位点的胞嘧啶(C)是优异等位变异。

[Objective]The sucrose non-fermenting protein kinase （SnRK） is a kind of Ser/Thr protein kinase found widely in plants and participates a variety of transductions in signaling pathway in plants. TaSnRK2.10 is an important SnRK2 member involved in response to various abiotic stresses in wheat （Triticum aestivum L.）. The objective of this study is to detect the single nucleotide polymorphism （SNP） of TaSnRK2.10, develop and map its functional markers, analyze the relationship between its haplotypes and phenotypic traits, and provide a basis for the genetic improvement and germplasm enhancement by molecular marker assisted selection in wheat. [Method] Thirty hexaploid wheat accessions with high polymorphism and their diploid and tetraploidwild relative species were selected to detect the nucleotide polymorphism in TaSnRK2.10-A gene by sequencing. A set of Chinese Spring nulli-tetrasomic lines and the recombinant inbred lines （RIL） derived from a cross of“Yanzhan 1 × Neixiang 188”were used to map TaSnRK2.10-A on chromosome. Based on the polymorphism in the sequence of TaSnRK2.10-A molecular markers were developed. The relevance between TaSnRK2.10-A haplotypes and phenotypic traits was analyzed using a natural population consisted of 262 historical wheat accessions. [Result] The sequences of TaSnRK2.10 on genomes A and D were cloned, named as TaSnRK2.10-A and TaSnRK2.10-D. There was no SNP detected in the sequence of TaSnRK2.10-D, but the full length of TaSnRK2.10-A was 4 688 bp with 15 SNPs and 2 InDels. Among them, 8 SNPs were identified in the promoter region, 2 SNPs in 5′-UTR region, and 5 SNPs in the coding region with 2 SNPs in exon. One of SNPs in exon was non-synonymous mutation. Four markers were developed. They were PM1 and PM2 for the promoter region, GM1 and GM2 for the coding region. TaSnRK2.10-A was mapped in the intervals between markers Xwpt7001 and WMC48 on chromosome 4A, with 5.1 cM and 25.7 cM from the flanking markers. In the natural populations consisted of 262 accessions, four haplotypes of TaSnRK2.10-A were detected by four markers that were associated with 1000-grain weight, spike per plant and spikelet per spike. The HapⅡand HapⅢof TaSnRK2.10-A are considered as potential superior haplotypes for the improvement of 1000-grain weight. The base C at the site of 4 184 bp is a superior allele for high 1000-grain weight.[Conclusion]The present research mapped TaSnRK2.10-A on the chromosome 4A. The HapⅡand HapⅢof TaSnRK2.10-A are considered as potential superior haplotypes for the improvement of 1000-grain weight, while HapⅣis a potential superior haplotype for spike per plant. The cytosine （C） at the position of 4 184 bp is the superior allele.