基于matK和rbcL序列的石斛属植物亲缘关系研究

Genetic relationship analysis of Dendrobium plants based on chloroplast matK and rbcL gene

采集了中国6个省份的铁皮石斛种质资源共22份,通过叶绿体基因matK和rbcL进行克隆测序,同时结合已报道的近缘物种matK序列33个和rbcL序列30个进行系统进化分析及分子鉴定。序列结果显示:matK基因序列平均长度为1708 bp,GC含量32%,保守位点768个,简约信息位点871个;rbcL基因序列平均长度1332 bp,GC含量42.9%,保守位点802个,简约信息位点24个。遗传多样性分析表明:matK序列单倍型数量(H)32个,单倍型多态性水平(Hd)0.842,核苷酸多态性(π)0.27016;rbcL序列H为10个,Hd为0.664,π为0.02611;序列分析及遗传多样性显示matK序列的分析结果具有更大的遗传多样性。遗传聚类结果显示不同产地的铁皮石斛与已有报道的石斛属各聚一支,相同产地铁皮石斛的聚类结果也与其地理分布基本一致。matK序列作为石斛属系统进化关系及亲缘关系分析具有更高的遗传多样性;中国6个省份铁皮石斛种质资源在进化上也具有一定的地域性特征。

Dendrobium officinale is a Chinese herbal medicine and mainly cultivated artificially with multiple botanical origins.A total of 22 D.officinale samples were collected from six different localities of China.The chloroplast genes matK and rbcL form 22 samples were amplified using PCR,and the purified PCR products were sequenced.These samples sequences with 33 matK and 30 rbcL sequences of different Dendrobium species were analyzed on sequence features,genetic variation and phylogenetic relationships.The average length of matK sequences were 1708 bp,and average GC content was 32%with 768 conserved(polymorphic)sites and 871 parsimony informative sites;the average length of matK sequences were 1332 bp,and average GC content was 42.9%,802 conserved(polymorphic)sites and 24 parsimony informative sites.In genetic diversity,the haplotypes(H)of matK sequence was 32,values of haplotype polymorphism(Hd)was 0.842,and nucleotide diversity(π)was 0.27016.For rbcL sequence,H was 10,Hd was 0.664,andπwas 0.02611.The genetic diversity of the populations of D.officinale was very high.In the phylogenetic trees,both gene matK and rbcL presented almost in all samples as a group with the D.officinale and consistent with their geographical distributions.In conclusion,the matK sequence had higher genetic diversity for phylogenetic analysis of Dendrobium.There was obvious regional characteristics in evolution for germplasm resources of D.officinale in six different provinces of China.