Genetic variation of Taxus cuspidata SIEB. et Zucc. in Korea

摘要

Japanese yew (Taxus cuspidate SIEB. et ZUCC.) is a shade-tolerant, dioecious gymnosperm native to Korea, Japan, Manchuria and eastern Siberia. Five natural populations of T. cuspidata in Korea were investigated using starch-gel electrophoresis in an attempt to determine the extent and distribution of genetic variation. The level of genetic diversity (A = 1.7, P-95 = 45.7%, P-99 = 60%, H-o = 0.172, and H-e = 0.168) and the degree of genetic differentiation (G(ST) = 0.067) were comparable to those of other conifers with similar life-histories and ecological traits. Five natural Japanese yew populations seemed to be in equilibrium with the expectations of HARDY-WEINBERG. Isolation by distance was detected. NEI's genetic distance, D, was positively correlated with geographic distance (r = 0.794, p = 0.006). Nm, the number of migrants per generation, was 3.48 and 2.87, depending on estimation procedure, and is similar to values in wind-pollinated conifers. Individual trees widely scattered around natural populations appeared to be critical to the maintenance of genetic variation in Japanese yew. Implications for the conservation of genetic diversity of T. cuspidata are discussed.