小麦Kr基因片段的克隆及序列分析

小麦远缘杂交不亲和性受Kr基因控制.为研究不同基因型小麦Kr基因的序列特征,从中国小麦微核心种质中选择蚂蚱麦、小白芒、托克逊1号、中国春、洋麦、郑麦9023等6种基因型小麦为试验材料,采用同源克隆方法,分离小麦Kr基因并分析其序列特征.结果表明,6种基因型小麦中有3种扩增出Kr基因片段,3条DNA序列长度均为414 bp,序列同源性为99.8％,仅在2个核苷酸位点处存在SNPs.Blast分析表明,该序列与小麦S位点受体激酶基因相同区域的序列同源性达85％,初步预测小麦Kr基因可能与植物自交不亲和基因一样,能促进柱头乳突细胞积累胼胝质,影响外源花粉的竞争力,最终导致小麦远缘杂交不亲和.

Cloning and Sequence Analysis of Kr Gene Fragment in Wheat

The incompatibility of distant hybridization in wheat is controlled by Kr genes.In order to research the sequence features of different genotypes of Kr genes,six genotypes from Chinese wheat micro-core collection,such as Mazhamai,Xiaobaimang,Tuokexunyihao,Chinese spring,Yangmai,Zhengmai9023,were used to clone Kr genes with the homology cloning method.The results showed that one amplified Kr gene fragment was cloned from three genotype wheat and these three DNA fragments were 414 bp in length with 99.8% of the sequence homology and only two SNPs in homologous regions.Blast analysis indicated that the sequence homology is 85% between Kr gene and S-locus receptor kinase gene in the same regions.Thus,the Kr gene was preliminarily speculated to possess similar function with plant self-incompatibility gene,which promoted cellulae mastoideaes to accumulate calloses in chapiters,and influenced the competitive ability of exogenous male pollens,which eventually resulting in the incompatibility of distant hybridization in wheat.