基于DNA拓扑异构酶II基因部分序列的侧耳属系统发育分析

对侧耳属（Pleurotus）14个种的14个菌株，亚侧耳属（Hohenbuehelia）1个种和离褶伞属（Lyophyllum）1个种的DNA拓扑异构酶II（EC 5.99.1.3）部分序列进行扩增分析。以灰盖鬼伞（Coprinus cinereus）、新型隐球酵母（Cryptococcus neoformans）和玉米黑粉菌（Puccinia polysora）等担子菌为外群，采用最大距离法、最大简约法和最大似然法构建侧耳属的系统发育树。结果表明：作为外群的三个物种独立于所有供试材料；侧耳属菌株作为一大类与供试的离褶伞属和亚侧耳属分开。侧耳属14个种又可细分成六支：可能为侧耳属起源最早的P. flabellatus、P. salmoneostramineus和P. djamor组成一组；P. tuberregium和P. pulmonarius均自成一组；P. abalonus和P. cystidiosus均产生束梗孢，聚为同组；P. eryngii var. eryngii、P. eryngii var. ferulae和P. nebrodensis为一组；另一组由P. ostreatus、P. columbinus、P. cornucopiae和P. citrinopileatus组成。按照侧耳属物种菌丝类型的不同，构建的系统发育树将该属14个种进行系群划分，单、二系菌丝分属于各个不同的分支中，说明单、二系菌丝均为多系起源，与用28S rDNA序列进行系统分析的结果一致。

Phylogenetic Relationship of Pleurotus Species based on Partial Sequences of DNA Topoisomerase II

Partial sequences of DNA topoisomerase II (EC 5.99.1.3) were amplified from 14 strains each representing one species in the genus of Pleurotus (Jacq.:Fr.) P. Kummer, one species from Hohenbuehelia, and one species from Lyophyllum. The phylogenetic relationship was inferred with clustering algorithm of distance matrix, maximum parsimony and maximum likelihood, and the functional outside group contained three species of Coprinus cinereus, Cryptococcus neoformans and Puccinia polysora in Basidiomycetes. In all the phylogenetic trees, the Pleurotus species were clustered in one clade separated from the other two taxonomically more distant species, and the outside group species were placed undependably. Within Pleurotus clade, the 14 strains were further divided into six groups. One cluster contains the earliest differentiated species including P. flabellatus, P. salmoneostramineus and P. djamor. P. tuberregium and P. pulmonarius each forms an independent branch. The two synnemata-producing fungi, P. abalonus and P. cystidiosus, are grouped together. One group has P. eryngii var. eryngii, P. eryngii var. ferulae and P. nebrodensis, and the last one comprises P. ostreatus, P. columbinus, P. cornucopiae and P. citrinopileatus. Further examination based on the mycelium morphology revealed that most of the monophyletic groups contain both monomitic and dimitic hyphae species, suggesting that this structure is polyph yletic origin, which matches the result by using 28S rDNA.