基于叶绿体基因组变异位点的兰属(兰科)植物资源遗传多样性的分子鉴定新方法  

A Novel Method for Molecular Identification of Genetic Diversity of Plant Resources in Cymbidium Sw. (Orchidaceae) Based on Taxon-Specific Variable Nucleotide Characters from Complete Chloroplast Genome

作　　者：刘美辰 左云娟 靳晓白 杨志荣[5] 索志立[6] 

机构地区：[1]北京市食品检验研究院(北京市食品安全监控和风险评估中心),北京 [2]中国科学院东南亚生物多样性研究中心,云南 勐腊 [3]中国科学院西双版纳热带植物园综合保护中心,云南 勐腊 [4]国家植物园,北京 [5]中国科学院植物研究所国家植物标本馆,北京 [6]中国科学院植物研究所系统与进化植物学国家重点实验室,北京

出　　处：《计算生物学》2024年第2期13-28,共16页Hans Journal of Computational Biology

摘　　要：准确鉴定物种遗传多样性是植物资源保护和可持续利用的基础。兰属Cymbidium Sw.是单子叶植物,具有极高的观赏、药用和科研价值。由于形态特征受到发育阶段和环境条件的影响,不同学者对形态特征的理解和判断也存在差异,基于形态特征的兰属植物的鉴定存在困难。我们利用兰属的3个种的叶绿体基因组序列中的物种特有的1285个核苷酸变异位点作为分子性状编制分子鉴定检索表,成功鉴定供试样品。物种特有变异位点的数量和核苷酸构成存在种间差异。西藏虎头兰Cymbidium tracyanum L. Castle (1185)的特有变异位点的数量最多,分别是秋墨兰Cymbidium haematodes Lindl. (53)和莲瓣兰Cymbidium tortisepalum Fukuy. (47)的特有变异位点的数量的22倍和25倍。西藏虎头兰的特有变异位点中,A (31.39%)或T (30.97%)的比例明显高于C (20.08%)或G (17.55%)。莲瓣兰的特有变异位点中,A (21.28%)的比例略低于T (25.53%)、C (27.66%)或G (25.53%)的比例,T、C或G的比例差异较小。秋墨兰的特有变异位点中,C (32.08%)的比例明显高于T (18.87%)的比例,A (26.42%)和G (22.64%)的比例间于C的比例和T的比例之间,差异不大。结果显示,叶绿体基因组的单核苷酸变异位点信息,可用于兰属植物资源遗传多样性的分子鉴定。调查了中国过去120多年来兰属植物标本的收集和馆藏现状,讨论了存在的问题与对策。本研究对于兰属植物的分类修订、种质资源的保护和利用具有重要价值。Accurate identification of genetic diversity is essential for conservation and sustainable utilization of plant resources. Plants of Cymbidium Sw. are extremely valuable for ornamental and medicinal uses as well as for scientific research. Since morphological characteristics are subjected to influences of developmental stages and environmental conditions, and there are differences among researchers in understanding and judgement on the morphological features, difficulties may occur in identification of Cymbidium plants. In this paper, 1285 taxon-specific variable nucleotide characters in the complete plastome of 3 species of Cymbidium were used as molecular traits to identify the plant genetic resource diversity of this plant genus and to compile a molecular classification key for the first time. There are differences in aspects of the amount and the base composition of variable nucleotide characters among the species. The amount of taxon-specific variable nucleotide characters in Cymbidium tracyanum L. Castle (1185) is the highest, being 22 times that of C. haematodes Lindl. (53) and 25 times that of C. tortisepalum Fukuy. (47). In C. tracyanum, the proportion of A (31.39%) or T (30.97%) is significantly higher than that of C (20.08%) or G (17.55%). The proportion of A (21.28%) is lower than that of T, C or G (25.53%~27.66%) in C. tortisepalum. In C. haematodes, the proportion of C (32.08%) is higher than that of T (18.87%), the proportion of A (26.42%) or G (22.64%) is between those of C and T which have minor differences in value. Our results indicated that taxon-specific variable nucleotide characters from the plastomes could be used for distinguishing different species successfully in Cymbidium. The status of Cymbidium plant specimens collected in the past over 120 years in China is investigated and problems and possible strategies are discussed. This study is valuable for taxonomic revision, conservation and utilization of Cymbidium plant germplasm resources.

关 键 词：兰科 兰属 植物资源多样性 叶绿体基因组 核苷酸变异位点 分子鉴定 

分 类 号：R71[医药卫生—妇产科学]