- 期刊
瀕絕物種烏來杜鵑的族群內遺傳變異研究
Study of AllozymeVariation within Population of Endangered Species-Rhododendron kanehirai Wilson
摘要
烏來杜鵑（Rhododendron kanehirai Wilson）天然族群已因原生育地破壞而消失，區外保育（ex situ conservation）為本種復育工作的第一步。研究其遺傳變異度之高低，復為更迫切之工作。本報告採取保存於臺灣省林業試驗所苗圃中收集的烏來杜鵑60個單株為樣品，逐個進行同功酶檢測，結果發現在15種酵素中，多型對偶基因僅存於PER, SKDH, PGI-2, LAP-2等4個基因座上。多型基因百分比為16.7%。其中除PER普遍呈多型性存於族群內之外，其餘各式多型基因分別分佈在10株個體中。依照此初步數據判斷，本種的復育在方法上，應先行繁殖這10株保有基因多型性的殘存個體，以維持其族群比例（population ratio）。並且在增加數量的過程中能保持足夠的有效族群大小（effective population size (Ne)），以免在復育過程中，因選擇不當，盲目繁殖大量同質個體造成基因僵化（fixed），反致加速該物種之滅絕。
並列摘要
Rhododendron kanehirai Wilson is an endemic species of Taiwan. It occurs only on steep banks along the Pei-Shih creek in restricted areas of northern Taiwan. R. kanehirai has been extincted due to the habitat destruction-the construction of the Emerald Reservoir. By 1992, the number of individuals of this species reduced below 100 and remained only in a nursery in Taiwan Forestry Research Institute in Taipei. Artificial by means of cuttings from these survivors is primarily, and in Taiwan exclusively way for propagation. However, for restoration of this species, to investigate the genetic variation within small population will be important. In this report, starch gel electrophoresis was used to study the isozyme phenotypes of 60 individuals of R. kanehirai. Four of the eighteen surveyed genetic markers (SKDH, PGI, PER and LAP) represent polymorphisms. Genetic variation is low of this species (He= 0.064). Mean number and effective number of alleles per locus (A=1.20; Ae=1.07) are also low. Allozyme data of this report indicates that restricted gene flow and genetic drift in small and isolated population may reduce genetic variability. These results are discussed in terms of the strategies for ex situ conservation and population restoration.