基于ISSR标记的卡特兰种质资源遗传多样性分析

Analysis of Genetic Diversity of Cattleya Germplasms by Using ISSR Markers

【目的】分析卡特兰属(Cattleya)植物的遗传多样性并评价其亲缘关系,为卡特兰的品种鉴别、分类、遗传图谱构建及分子育种打下基础。【方法】采用ISSR分子标记技术,从100条ISSR引物中筛选出扩增条带清晰、多态性高、重复性好的引物对18份卡特兰种质资源进行PCR扩增,并利用GenAlEx 6.51计算各种间的遗传多样性参数;采用NTSYS 2.1的非加权算术平均聚类(UPGMA)法进行聚类分析。【结果】利用筛选出的6条引物对供试材料进行PCR扩增获得153条谱带,多态性条带比率达100%;遗传多样性参数中,平均观测等位基因数(Na)为2.000个,平均有效等位基因数(Ne)为1.207个,平均Nei’s遗传多样性指数(He)为0.157,平均Shannon信息多样性指数(I)为0.281;卡特兰种质资源间的遗传相似系数在0.6514~0.8991;UPGMA聚类分析结果表明,在相似系数0.749处,可将18份卡特兰种质资源划分为6个类群。【结论】卡特兰种质资源间具有丰富的遗传多样性;UPGMA聚类分析结果与传统的形态学分类结果基本一致,18份卡特兰种质资源分别隶属于卡特亚属、波浪边亚属、类匈伯加亚属、镰刀形花亚属、因特美地亚属、藕茎花亚属和圈聚花兰属7个属。

【Objective】The genetic diversity of Cattleya germplasmswas studied to evaluate the relationship between the various species or varieties and to lay the theoretical foundation for identification,classification,genetic map construction and molecular breeding of Cattleya.【Method】Based on 18Cattleya germplasm resources as the test materials,primers with clear amplified bands,high polymorphism and positive repeatability were selected among the 100 primers for genetic diversity analysis of the samples.GenA1 Ex 6.51 software was utilized for calculating genetic diversity parameters.Clustering analysis was conducted with NTSYS 2.1 UPGMA method.【Result】PCR amplification with 6 primers generated 153 bands,by all of which were polymorphic(100%).Genetic diversity parameters were estimated,average value of observed allele number(Na),number of effective alleles(Ne),Nei′s gene diversity(He)and Shannon′s information index(I)were 2.000,1.207,0.157 and 0.281,respectively.Genetic similarity coefficients ranged between 0.6514 and 0.8991.18 Cattleya germplasm resources were divided into 6 groups at the similarity coefficient of 0.749 based on UPGMA cluster analysis.【Conclusion】The results of ISSR-PCR analysis showed that there were abundant genetic diversity among Cattleya germplasm resources.UPGMA cluster analysis results are basically consistent with the traditional morphological classification results.The 18 Cattleya germplasm resources were divided into 7 genera,which were Cattleya,Crispae,Schomburgkoidea,Falcata,Intermedia,Rhizantha and Guarianthe.