崔学强 唐璇 黄昌艳 邓杰玲 李秀玲 卢家仕 张自斌

摘  要：以48份石斛兰种质资源为对象，采用iPBS分子标记技术对其遗传多样性进行分析并构建DNA指纹图谱。结果表明：从83条iPBS引物中筛选出7条扩增条带清晰、多态性高、重复性好的引物;利用筛选出的引物对48份石斛兰基因组DNA进行PCR扩增，共获得279条谱带，其中多态性条带279条，多态性比例为100%;采用GenAlEx 6.5软件计算48份石斛兰的平均观测等位基因数（Na）为2.000，平均有效等位基因数（Ne）为1.202，平均Neis遗传多样性指数（He）为0.153，平均Shannon信息多样性指数（I）为0.274，48份石斛兰表现出丰富的遗传多样性;采用NTSYS-pc 2.1软件计算得到48份石斛兰间的遗传相似系数为0.6667～0.9211，基于遗传相似系数进行UPGMA聚类，在相似系数0.75处，可将48份石斛兰划分为7个类群。利用2对引物构建的DNA指纹图谱可单独鉴别出48份石斛兰种质资源，该图谱可为石斛兰分类与鉴定提供科学依据。

关键词：石斛兰;iPBS分子标记;遗传多样性;DNA指纹图谱

Abstract： The genetic diversity of 48 Dendrobium germplasm resources was analyzed and DNA fingerprint was constructed by the iPBS molecular marker technique. The results showed that seven primers with clear amplification bands， high polymorphism and good repeatability were selected from 83 iPBS primers. The selected primers were used to amplify the genomic DNA of 48 Dendrobium germplasm resources by PCR， and a total of 279 bands were generated， of which 279 were polymorphic bands， and the polymorphic ratio was 100%. By GenAlEx 6.5 software， average value of observed allele number， effective number of alleles， Nei's gene diversity and Shannon's information index was 2.000， 1.202， 0.153 and 0.274， respectively， indicating that a high level of genetic diversity among the 48 Dendrobium germplasm resources. The genetic similarity coefficient among the 48 Dendrobium germplasm resources ranged from 0.6667 to 0.9211 by NTSYS-pc 2.1 software. UPGMA clustering based on genetic similarity coefficient revealed the 48 Dendrobium germplasm resources could be divided into seven groups when genetic similarity was 0.75. The DNA fingerprint map constructed with two pairs of primers could separately identify the 48 Dendrobium germplasm resources， which could provide a scientific basis for the classification and identification of Dendrobium.

Keywords： Dendrobium; iPBS molecular marker; genetic diversity; DNA fingerprinting

石斛蘭（Dendrobium）是兰科（Orchidaceae）石斛属植物的总称，全球约2000个原生种，中国原产80余种[1]。石斛兰因其花色鲜艳，花姿优美，花期长，具芳香气味，而与卡特兰（Cattleya）、蝴蝶兰（Phalaenopsis）、文心兰（Oncidium）并列为观赏价值最高的“四大观赏洋兰”[2]。部分石斛兰还是我国传统的名贵中药材，其中铁皮石斛（Dendrobium officinale）、金钗石斛（Dendrobium nobile）、鼓槌石斛（Dendrobium chrysotoxum）、流苏石斛（Dendrobium fimbriatum）等均被收录在《中国药典》中[3-4]。目前，石斛兰已被广泛栽培于世界各地，经过育种家开展的新品种的选育工作，已有不少经典石斛兰品种流行于市场。中国开展石斛兰新品种选育较晚，目前市场上流行的品种大部分都是从国外引进的品种。……