Phylogeny of the genus Chrysanthemum L.: evidence from single-copy nuclear gene and chloroplast DNA sequences.

摘要: Chrysanthemum L. (Asteraceae-Anthemideae) is a genus with rapid speciation. It comprises about 40 species, most of which are distributed in East Asia. Many these narrowly and habitat-specific. Considerable variations morphology ploidy found this genus. Some species have been the subjects many studies, but relationships between its allies phylogeny remain poorly understood. In present study, 32 species/varieties from 11 allied genera were analyzed using DNA sequences single-copy nuclear CDS gene seven cpDNA loci (psbA-trnH, trnC-ycf6, ycf6-psbM, trnY-rpoB, rpS4-trnT, trnL-F, rpL16). The trees both suggest that 1) not monophyletic taxon, affinity Ajania so close two should be incorporated taxonomically; 2) Phaeostigma more closely related to Chrysanthemum+Ajania than other generic allies. According pollen data, purpurea member Phaeostigma. Species differentiation appears correlated geographic environmental conditions. Chinese can divided into groups, C. zawadskii group indicum group. former northern China latter southern China. polyploid such as argyrophyllum, may originated allopolyploidization involving divergent progenitors. Considering all evidence previous we conclude ecological factors well hybridization polyploidy play important roles divergence speciation Chrysanthemum.