Origins of polyploidy in coast redwood (Sequoia sempervirens (D. DON) ENDL.) and relationship of coast redwood to other genera of Taxodiaceae

摘要

Coast redwood (Sequoia sempervirens (D. DON) ENDL.) is the only conifer which is a hexaploid. It is not known when the polyploid Sequoia evolved from its diploid ancestors and which are its putative progenitors, living or extinct. The polyploid nature of the coast redwood, whether autopolyploid, auto-allopolyploid, segmental allopolyploid, or allopolyploid also remains an unresolved problem.