基于accD基因序列的牛至遗传多样性研究

Study on Genetic Diversity of Origanum Vulgare L.Based on accD Gene Sequence

目的基于acc D基因序列分析不同产地牛至的遗传结构与分化,考察其遗传多样性。方法以8个居群69份样品为材料,试剂盒法提取植物基因组DNA,同源克隆法获得acc D序列,Sanger测序法双向测序,利用DNAsp、Arlequin等软件进行多态性分析,MEGA软件计算遗传距离并构建NJ发育树。结果牛至acc D长度为1432-1436 bp,存在10个单倍型与16个变异位点,单倍型多态性为0.595,核苷酸多样性为0.15750;牛至居群遗传分化较高(Gst=0.36751,Nst=0.46976,Fst=0.67627),基因流较低(Nm=0.43),居群间变异(67.62%)是主要的变异来源。系统发育关系显示10种单倍型形成3大分支,主要以H2为中心形成发散状的系统结构,种群未发生扩张。结论牛至居群存在较高的遗传多样性与遗传分化,可能主要与生境片段化、种群隔离及生活史特征相关,本研究为牛至种质资源的保护和开发利用提供理论基础。

Objective To analyze the genetic structure and differentiation of O.vulgare from different origins based on the accD gene sequence,and to investigate its genetic diversity.Methods Using 69 samples from 8 populations as materials,plant genomic DNA was extracted by kit method,accD sequence was obtained by homologous cloning method,and Sanger sequencing method was used for bidirectional sequencing.The DNAsp and Arlequin software were used for polymorphism analysis,and MEGA software was used to calculate genetic distance and construct NJ developmental tree.Results The results showed that the sequence length of accD was 1432-1436 bp,with 10 haplotypes and 16 variation sites.The haplotype diversity was 0.595,and the nucleotide diversity was 0.15750.O.vulgare populations had higher genetic differentiation(Gst=0.36751,Nst=0.46976,Fst=0.67627)and lower gene flow(Nm=0.43),which Inter-populations variation(67.62%)was the main source of variation.The phylogenetic relationship showed that the 10 haplotypes formed 3 major branches which mainly forming a divergent phylogenetic structure with H2 as the center,and the population had not expanded.Conclusion O.vulgare populations had high genetic diversity and genetic differentiation,which was mainly related to habitat fragmentation,population isolation and life history characteristics.This study provides a theoretical basis for the protection,development and utilization of O.vulgare germplasm resources.