@ARTICLE{TreeBASE2Ref19415,
author = {Syou Kato and Kazuharu Misawa and Fumio Takahashi and Hidetoshi Sakayama and Satomi Sano and Keiko Kosuge and Fumie Kasai and Makoto Watanabe and Jiro Tanaka and Hisayoshi Nozaki},
title = {Intraspecific phylogeny of Chara braunii (Charales) based on chloroplast and nuclear DNA regions},
year = {2011},
keywords = {},
doi = {},
url = {http://},
pmid = {},
journal = {Journal of Phycology},
volume = {},
number = {},
pages = {},
abstract = {Many of the genes that control photosynthesis are carried in the chloroplast. These genes differ among species. However, evidence has yet to be found revealing the involvement of organelle genes in the initial stages of plant speciation. To elucidate the molecular basis of aquatic plant speciation, we focused on the unique plant species Chara braunii that inhabits both shallow and deep freshwater habitats and exhibits habitat-based dimorphism of chloroplast DNA (cpDNA). Here, we examined the ?shallow? and ?deep? subpopulations of C. braunii using two nuclear DNA (nDNA) markers and cpDNA. Genetic differentiation between the two subpopulations was measured in both nDNA and cpDNA regions, although phylogenetic analyses suggested nuclear gene flow between subpopulations. Neutrality tests based on Tajima?s D demonstrated diversifying selection acting on organelle DNA regions. Furthermore, both ?shallow? and ?deep? haplotypes of cpDNA found in cultures originating from bottom soils of three deep environments suggested that migration of oospores (dormant zygotes) between the two habitats occurs irrespective of the complete habitat-based dimorphism of cpDNA from field-collected vegetative thalli. Therefore, the two subpopulations are highly selected by the their different aquatic habitats and show pre-zygotic isolation, which represents an initial process of speciation affected by ecologically based divergent selection of organelle genes.}
}