Phylogenetic and biogeographic implications of chloroplast DNA variation in Picea

摘要

Purified chloroplast DNA (cpDNA) extracts from 31 species ofPiceaand two species ofPinus (P. sylvestrisandP. cembra) were digested with eight restriction endo‐nucleases, separated by electrophoresis and scored for restriction fragment length polymorphisms. The resulting data was analyzed phenetically and cladistically. The phenetic analysis indicated lower levels ofcpDNAdifferentiation withinPiceathan withinPinusand lower levels of differentiation among Eurasian than among North‐AmericanPiceaspecies. The cladistic analysis, usingPinus sylvestrisas an outgroup, suggested monophyly forPiceaand resolved several monophyletic groups among the 31 species ofPicea. An assessment of biogeographic events, based on the cladogram, suggests thatPiceaoriginated in North‐America and that the colonization of Eurasia occurred through separate, intercontinental migra