Title

雌雄異株稀有植物傘花木(Eurycorymbus caraleriei)自然居群的等位酶遺傳多樣性研究

Translated Titles

Allozymic Genetic Diversity in Eurycorymbus caraleriei (Levi.) Rehd. et Hand.-Mazz., an Endemic and Dioecious Tree in China

Authors

朱紅豔(Hong-Yan Zhu);康明(Ming Kang);葉其剛(Qi-Gang Ye);黃宏文(Hong-Wen Huang)

Key Words

傘花木 ; 孑遺植物 ; 單屬種植物 ; 居群遺傳結構 ; 遷地保育 ; Eurycorymbus caraleriei Levl. Rehd. et Hand.-Mazz. ; Relic plant species ; Monospecies genus ; Population genetic structure ; Ex situ conservation

PublicationName

植物科學學報

Volume or Term/Year and Month of Publication

23卷4期(2005 / 08 / 01)

Page #

310 - 318

Content Language

簡體中文

Chinese Abstract

傘花木(Eurycorymbus caraleriei)為中國特有的第三紀孑遺單種屬植物,雌雄異株。採用超薄平板微型聚丙烯酰胺等電聚焦電泳方法對其5個自然居群和1個人工遷地保護居群的等位酶變異進行了初步研究。對7個酶系統中14個位點的等位酶居群遺傳多樣性及遺傳結構分析結果表明:傘花木具有較高水平的遺傳多樣性,其每位點平均等位基因數A=1.6,平均多態位點比率P=42.9%,平均預期遺傳雜合度H(下標 e)=0.216;各居群的遺傳多樣性無顯著性差異,但都表現為嚴重偏離Hardy-Weinberg平衡的雜合子過量;其遺傳變異主要發生在居群內(93.1%),居群間分化較小(G(下標 st)=0.069),居群間遺傳一致度較高(I=0.965~1.000)。推斷這可能是由於其古老孑遺性、雌雄異株、混和傳粉方式的生物學特性以及其長壽命的生活史等原因所導致;同時,居群間的較高基因流(Nm=3.128)也可能起到很大的作用。還使用UPGMA聚類方法推斷了武漢植物園遷地保護的野外居群來源,在對遷地保護居群的評價中發現遷地保護居群僅保存了該物種基因型多樣性的16%,在此基礎上提出了今後進一步的保育策略。

English Abstract

Allozymic variation of five natural populations and one ex situ population of Eurycorymbus caraleriei (Levl.) Rehd. et Hand.-Mazz. was analyzed using isoelectric focusing in thin-layer polyacrylamide slab gels. Fourteen loci of seven enzyme systems were scored for the analysis of population genetic diversity and structure. A high genetic diversity was observed in this dioecious species, with mean number of alleles per locus A=1.6, mean percentage of polymorphic loci P=42.9% and average expected heterozygosity H(subscript e),=0.216. An excess of heterozygous genotypes was found in all populations, which resulted in a significant deviation from the Hardy-Weinberg equilibrium. The low value of the relative magnitude of genetic differentiation among populations (G(subscript st)=0.069) suggests little genetic differentiation and a sufficient gene flow (Nm=3.128) occurred among natural populations. UPGMA cluster analysis using Nei's (1978) unbiased genetic distance revealed that the ex situ population was firstly clustered with Shimen population, suggesting the ex situ collection is probably form Shimen population. Although the gene diversity in ex situ collection was found for accounting for about 85% of the total genetic variation in the species, genotype diversity retained in ex situ collection only covered about 16% of the total of the species. As the result, we strongly recommend that more genotypes should be collected from natural populations to maintain the genetic integrity of the species in ex situ collection.

Topic Category 生物農學 > 植物學