杨梅endo-PG基因单核苷酸多态性(SNP)分析

Single Nucleotide Polymorphism(SNP)Analysis of the Endopolygalacturonase Gene in Chinese Bayberry(Myrica rubra)

Endo-PG基因在果实肉质变化以及后熟软化过程中发挥重要作用。采用PCR直接测序法对45份杨梅试材中endo-PG基因的部分DNA序列进行单核苷酸多态性分析,测序总长度为1 866bp,共发现178个SNP,其中,单现突变位点为60个,简约信息位点为118个,核苷酸多态性值(Pi)为0.27。通过单倍型分析发现在45份杨梅试材中的endo-PG基因存在12种单倍型。基于邻接法NJ构建endo-PG基因系统进化树,结果表明45份杨梅试材被划分为4个组,聚类结果与果实硬度存在一定联系;此外,‘荸荠’等品种存在2种等位基因,且两者差异较大,被划分于不同分组;而‘东魁’等品种纯合度相对较高。

Endo-PGplays an important role in the ripening of Chinese Bayberry（Myrica rubra）fruit by causing its softening and inducing textural changes.45 Chinese Bayberry accessions were tested to detect single nucleotide polymorphisms（SNPs）in the endo-PGgene by PCR-based sequencing of a 1 866 bp long DNA fragment.A total of 178 SNPs were identified,of which 60 were singleton variable sites and another 118 were parsimony informative sites.The nucleotide diversity value（Pi）was 0.27.A total of 12 haplotypes were identified and a dendrogram was constructed for endo-PG using the neighbor-joining（NJ）clustering method.The results indicated that the 45 accessions were clustered into four groups and that the clustering correlated with fruit hardness.Additionally,some cultivars（e.g.＇Biqi＇）were found to have two alleles,conferring pronounced phenotypic differences between allelic combinations and could thus be divided into different groups,while some other cultivars（e.g.＇Dongkui＇）had relatively high homozygosity.