粒毛盘菌属及其相关属的分子系统学研究*

晶杯菌科的分类目前主要基于子囊盘外囊盘被表面毛状物的形态学特征,在系统演化关系上十分不清楚。本研究利用18SrRNA基因核苷酸序列分析方法探讨该科粒毛盘菌属及其相关属间的系统发育关系。以Saccharomycescerevisiae为外群的严格合意树和最简约树表明,粒毛盘菌属与其相关的属形成三个分支。Lachnumhyalopus,L.nudipes和L.virgineum代表一个分支。L.brasiliense,L.sclerotii,L.singerianum,Albotrichaguangxiensis,Calycellinapopulina.,Cistellagrevillei,Hyaloscyphaaureliella,Lachnellulacalyciformis,Parachnopezizaguangxiensis和Trichopezizasulphurea聚在一起(支持率为57%),为另一个分支。上述两个姊妹分支的支持强度为76%。与Lachnum在形态上有些相似的Cistella和Lachnum聚在一起的支持强度为51%。传统上纳入Arachnopezizoideae的Parachnopeziza与该亚科的模式属Arachnopeziza的关系较远。Arachnopezizaaurata是供试的14个种中距离最远的一个,位于系统发育树的最外侧,与上述两个分支的亲缘关系较远,这对Arachnopezizoideae在晶杯菌科中的地位提出了质疑。

PHYLOGENETIC RELATIONSHIPS OF LACHNUM AND RELATED GENERA INFERRED FROM PARTIAL SEQUENCES OF 18S rDNA

Current classification of the Hyaloscyphaceae is based mainly on morphological characteristics, which does not reveal the phylogenetic relationships among genera in the family. Investigation of the phylogenetic relationships of Lachnum and some related genera by using sequence analysis of partial 18S rDNA was carried out and the results indicated that Lachnum and its allies are possibly not monophyletic and that three lineages were recognized. Lachnum hyalopus and its closely related species, L. nudipes and L. virgineum, represent one group. L. brasiliense, L. sclerotii, L. singerianum, Albotricha guangxiensis, Calycellina populina, Cistella grevillei, Hyaloscypha aureliella, Lachnellula calyciformis, Parachnopeziza guangxiensis, and Trichopeziza sulphurea constitute another one with a low bootstrap value (57%). As currently defined, Lachnum is probably paraphyletic or polyphyletic. Lachnum and Cistella somewhat similar in morphological features were grouped together with 51% bootstrap value and might be close. Parachnopeziza previously placed in the Arachnopezizoideae seemed not close to Arachnopeziza, the type genus of that subfamily. Of the 14 species examined, the most distant species is Arachnopeziza aurata, which suggests that the Arachnopezizoideae might not be closely related to other members of the Hyaloscyphaceae.