Taxonomic and evolutionary studies in the genus Usnea(Parmeliaceae, lichenized Ascomycota) focusing on the symbiotic relationship with photobiont.

点击翻译按钮获取中文摘要

The symbiotic relationship between mycobiont and photobiont in the lichen genus Usnea was examined based on the molecular phylogenetic trees. Mycobiont clades were fundamentally consisted of 3 subgenera and 2 sections within the genus. Several clades were also found within the clades of infrageneric taxonomic groups. Photobionts of Usnea belong to 9 clades within the genus Trebouxia. Most of the infrageneric groups of the mycobiont select each particular clade of photobiont. However, some of mycobiont clades share a same photobiont clade. Further examinations of other lichen photobionts in addition to those of Usnea suggest that symbiotic relationship in lichens may be due to sharing and selection of common alga within the habitat rather than strict cospeciation or global geographical difference of algal partners.