玉米淀粉合成相关基因ZmSSIIa 的序列变异分析

 玉米淀粉合成酶ZmSSIIa 在淀粉生物合成途径中主要作用是将支链淀粉的分支链由6~10 个延长至12~25 个, 对于玉米籽粒产量和品质具有重要的影响。本研究在86 个优异玉米自交系中对该基因进行基因序列定点捕获, 并获得该基因全长为4836 bp 的核苷酸序列。基因多态性分析发现, 该基因座位上有78 个SNP 和19 个Indel。玉米ZmSSIIa 基因的编码区具有24个SNP, 将该基因划分成9 种编码区单倍型, 并编码7 种ZmSSIIa 蛋白质。供试材料的群体中, ZmSSIIa 基因至少经历8 次重组, 可能对单倍型的分化和连锁不平衡具有重要作用。中性进化测试表明该基因在供试群体中没有明显的人工选择。

Analysis of Sequence Polymorphism for Maize Starch Biosynthesis Related Gene ZmSSIIa

The maize starch synthesis ZmSSIIa elongates amylopectin chains from degree of polymerization 6-10 to degree of polymerization 12-25 in the pathway of starch biosynthesis, and plays important roles in kernel yield and quality. The analysis of sequence polymorphism of maize ZmSSIIa gene will provide information for further detection of beneficial mutants associated with yield and quality. In order to reveal the sequence polymorphism of the maize ZmSSIIa gene, a total of 4836 bp sequence of this locus is captured in 86 elite maize inbred lines through a NimbleGensequence capture array. Analysis of the sequence polymorphism reveals that there are 78 SNPs and 19 Indels in this locus. The coding sequences of the maize ZmSSIIa gene contain 24 SNPs, which divide the coding regions into 9 haploytpes, and 7 different ZmSSIIa proteins are encoded by the tested inbred lines. At least 8 recombination events are found to contribute to the haplotype diversity and linkage disequilibrium between polymorphic sites in the maize ZmSSIIa gene. According to the results of the test of neutral evolution, there is no evidence of artificial selection for this gene in the tested inbred lines.