【作者】 王曼曼；

【导师】 侯成林；

【作者基本信息】 首都师范大学 ， 微生物学， 2009， 硕士

【摘要】 斑痣盘菌目成员在生物学上具有广泛的多样性,其寄主范围很广,包括裸子、被子及蕨类植物,它涉及的寄主植物多达58科,是世界菌物资源中的一个重要组成部分。该目成员的真菌系统学研究历史悠久且错综复杂,国内外关于斑痣盘菌目及相关类群的分子系统进化研究才刚刚起步。本试验通过DNA提取,PCR扩增,序列测定等步骤,共获得62个28S-rDNA序列和17个ITS序列,分别对28S-rDNA序列,ITS序列以及28Sr-DNA与ITS的联合序列进行分析,利用最大简约法和邻接法两种建树方法对针叶树生斑痣盘菌及其相关种的序列构建系统发育树,并以贝叶斯演绎法中的后验概率值(PP)和自展法(bootstrap)评估和分析所构建的系统发育树。具体结论如下:1、传统的斑痣盘菌目成员Naemacyclus sp.526c和Cyclaneusma minus 45与柔膜菌目亲缘关系更近,而形态学属于柔膜菌目的地锤菌科(Cudoniaceae)成员,Cudonia lutea,cudonia circinans,Cudonia sichuanensis,Spathularia flavida与斑痣盘菌目亲缘关系更近。这也与Gernandt et al.(2001)对18S-rDNA序列分析以及Hou(2004)对28S-rDNA序列分析所得出的结论一致。2、针叶树生斑痣盘菌形成一个大的进化支,而生长在阔叶树上的斑痣盘菌虽然在系统树中能够聚集到一起,但未能与针叶树生斑痣盘菌形成的分支完全分开;生长于针叶树不同部位的斑痣盘菌也形成不同的进化分支。3、根据分子生物学方法构建的系统树与根据形态学方法所建立的分类系统有所不同,形态上属于不同种、属或更高级分类单元的成员在本试验所构建的系统树中却能聚集到一起。这可能是由于形态学分类标准存在一些人为因素,两种分类方法所得到的结果也有所区别。如本试验所构建的ITS系统树中,Meloderma desmazieriAF203470,Meloderma desmazieri AF426056,Elytroderma deformans AF203469等种在Lophodermium属成员所形成的进化支中。因此形态学的一些分类标准,如子囊果在寄主组织中的埋生位置,子囊、子囊孢子的形状等单一因子做为属的分类特征并不合适。4、对28S-rDNA序列、ITS序列以及28S-rDNA序列与ITS序列的联合序列进行分析构建的系统树基本一致,而且部分分支得到很高的bootstrap值和后验概率值支持,但很多进化支依然没有得到解决,PP和bootstrap值相对较低,因此需要进一步研究,建议联合使用RPB2,mtSSU等基因序列进行多基因序列分析。更多还原

【Abstract】 Members of the Rhytismatales have a comprehensive biological diversity and a broad host spectrum.Their hosts belong to nearly 58 families,including gymnosperms, angiosperms and ferns.The Rhytismatales are a great important component of the world fungi resources.The history for classification of Rhytismatales is long and complex,but knowledge of molecular phylogeny of this group and the related fungi are limited.In this study,62 28S-rDNA sequences and 17 ITS sequences were gained,three kinds of sequences,28S-rDNA,ITS and their joint sequences were used for analyses of Maximum Parsimony(MP) methods and Neighbor-Joining(NJ) methods by PAUP*4.0b10 software.The posterior probabilities of Bayesian Inference and the bootstrap of Jackknife were used to evaluate the trees.The results were as followed:(1) Traditional members of Rhytismatales,Naemacyclus sp.526c and Cyclaneusma minus 45 were more closely related to Helotiales.According to the morphological studies,members belong to Cudoniaceae,Helotiales,however,Cudonia lutea,cudonia circinans,Cudonia sichuanensis,Spathularia flavida occured on the Rhytismatales clade.This is similar to the analysis of the 28S-rDNA analysis by Hou (2004) and the analysis of 18S-rDNAby Gernandt et al.(2001).(2) Rhytismatales from conifers formed a large clade,and those from broadleaf-hosts gathered together,but still in the conifer clade,The members of Rhytismatales from different host ogans of conifers formed own clade.(3) Molecular Phylgentic analyses results were not congruous with those of traditional classification.The species Meloderma desmazieri AF203470,Meloderma desmazieri AF426056,Elytroderma deformans AF203469 occurred in the Lophodermium clade in ITS trees.Theresore some morphological characters,such as the shape of ascocarps,ascus and ascospores and the position of ascocarps in the host,as were not important at the generic level.(4) The phylogenetic trees based on sequences of ITS,LSU and ITS+LSU rDNA were similar.Some clades have a high boostrap and posterior probability support, while the others with only lower supports.Therefore multigene analysis is proposed,for example,to combine the sequences of ITS,LSU,SSU,RPB2 or mtSSU to make a further study.更多还原