从18SrDNA序列初探散胞盘菌亚科属间亲缘关系(英文)

PRELIMINARY NOTES ON PHYLOGENETIC RELATIONSHIPS IN THE ENCOELIOIDEAE INFERRED FROM 18S rDNA SEQUENCES

散胞盘菌亚科Encoelioideae建于1932年，为盘菌纲Discomycetes锤舌菌目Leotiales锤舌菌科（广义）Leotiaceae的成员，它包括腐生、植物寄生、真菌上生的盘状子囊菌，现含18属，其中若干为单种属。传统分类从形态学角度将外囊盘表层细胞松散结合或者表面覆盖短的菌丝延伸物视为此亚科的主要特征，宏观上，其成员的共性表现为外囊盘被表面糠皮状、鳞屑状或霜状。迄今，学者们从未对散孢盘菌亚科这一性状是否反映属间亲缘关系进行过任何探讨，国际基因库中亦无此亚科的可利用序列。为了探明此性状在系统演化过程中的作用以及散胞盘菌亚科的属间亲缘关系，我们对此亚科中绿散胞盘菌Chlorencoelia、复柄盘菌属Cordierites、散胞盘菌属Encoelia、霍氏盘菌属Holwaya、拟爪毛盘菌属Unguiculariopsis、 以及丝绒盘菌属Velutarina代表种的18S rDNA片段进行了序列测定，受实验材料所限，每属只获得了一个种的18S rDNA序列。为了分析和比较，还对同一科内锤舌菌亚科Leotioideae中绿杯菌属Chlorociboria一个种的相关序列进行了测定。在构建系统树的过程中，核盘菌科的核盘菌Sclerotinia sclerotiorum被选为外群；从基因库中调入属于同一个目的地舌菌科和锤舌菌亚科几个属的代表即胶鼓菌属Bulgaria、锤舌菌属Leotia、?

The Encoelioideae containing about 18 genera is saprobic, plant-parasitic and mycoparasitic. Morphologically, members of the subfamily share the most common characteristic of loosely interconnected ectal excipular cells or short hyphal protrusions but show diversities in other details. In order to answer the question of phylogeny within the subfamily, 18S rDNA of species in Chlorencoelia, Cordierites, Encoelia, Holwaya, Unguiculariopsis, and Velutarina were sequenced. Sequences of a few other selected inoperculate discomycetes in the Leotiaceae and Geoglossaceae from GenBank were also introduced and Sclerotinia sclerotiorum was chosen as the outgroup. Our preliminary molecular phylogenetic analysis based on 18S rDNA sequences of the above taxa showed that the Encoelioideae is not monophyletic and four lineages can be recognized. Holwaya together with Bulgaria is the sister group of Leotia and Microglossum. Cordierites closely related to Encoelia is the sister group of Chlorociboria and Neobulgaria with low bootstrap value. Unguiculariopsis and Velutarina are clustered together with very high bootstrap value. Chlorencoelia is not closely associated with any genera tested in the subfamily.