| 摘要: |
| 采用随机扩增多态性DNA(RAPD)方法对孑遗植物台湾杉分布于湖北星斗山的野生和栽培居群共42个个体进行了遗传多样性分析。从60个随机引物中筛选出13个引物,共扩增出155条清晰谱带,多态位点百分率为72.9%。野生居群和栽培居群的多态位点百分率分别为65.81%和59.35%; Nei's基因多样性分别为0.2001和0.1911; Shannon's信息指数分别为0.3120和0.2946。野生居群的遗传多样性高于栽培居群,表明这些原生古树的后代出现了一定程度的遗传衰退。用UPGMA方法对42个单株聚类可知,来自野生群体的个体和来自栽培群体的个体明显地各聚为一类。尽管孑遗物种台湾杉在湖北仅有一个野生群体,且为零星分布,总个体数40多株,但仍保持较高的遗传多样性水平,这说明遗传多样性不是导致其种群濒危的主要原因,导致台湾杉种群濒危的原因可能与台湾杉自然种群及群落所处生境的直接破坏及其本身生物学和生态学特性所导致的自然更新不良有着密切的联系。 |
| 关键词: 台湾杉 濒危树种 RAPD 遗传多样性 |
| DOI： |
| 分类号:Q941 |
| Fund project: |
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| Analysis of genetic diversity of Taiwania cryptomerioides in Xingdoushan, Hubei Province |
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YANG Qin-Jun, CHEN Guang-Fu, LIU Xiu-Qun, CHEN Long-Qing*
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Key Laboratory of Horticultural Plant Biology, Ministry of Education/College of Horticulture
and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China
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| Abstract: |
| In this project,RAPD markers were used to investigate the level of genetic diversity of 42 individuals in the wild and cultivated populations of Taiwania cryptomerioides,which distributed in Xingdoushan National Natural Reserve of Hubei Province. 13 primers were selected from the tested 60 random primers and 155 DNA fragments were scored. The percentage of polymorphic loci of the wild and cultivated populations were 65.81% and 59.35%,respectively. Nei's gene diversity and Shannon's information measure(H)of the wild population were 0.2001 and 0.3120,respectively; while the corresponding values of the cultivated one were 0.1911 and 0.2946,respectively. The genetic diversity of the wild population was higher than that of the cultivated one. The results showed that the cultivated population had a certain extent genetic recession. In the UPGMA dendrogram based on Nei's genetic distance,the individuals from the wild and cultivated populations clustered respectively. Preliminary study showed that T.cryptomerioides maintained a relatively high level of genetic diversity,though there were nearly 40 wild trees distributing fragmently in Hubei Province. This meant that the main cause threatening its natural population was not the low genetic diversity. The endangered status of this taxon was mainly attributed to the habitat deterioration and disturbance,and the poor natural regeneration ability caused by its own biological and ecological characteristics. |
| Key words: Taiwania cryptomerioides endangered tree RAPD genetic diversity |
