DERIVATION OF XANTHOCYPARIS AND JUNIPERUS FROM WITHIN CUPRESSUS: EVIDENCE FROM SEQUENCES OF nrDNA INTERNAL TRANSCRIBED SPACER REGION

摘要

Sequences of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA were used to infer relationships of Cupressoideae. Fitzroya cupressoides, a genus in the Callitroideae, was used for rooting purposes. Thujopsis and Thuja form a clade,as do Fokienia and Chamaecyparis. Both Cupressus nootkatensis and C. funebris are more closely related to Cupressus than to Chamaecyparis. The Old World species of Cupressus form a clade that is sister to the clade containing Juniperus, Xanthocyparis, and the New World species of Cupressus. Juniperus and Xanthocyparis are each monophyletic and are probably derived from within Cupressus. We herein refer Xanthocyparis vietnamensis and X. nootkatensis to Cupressus.