【作者】 郭云忠；

【导师】 孙广宇；

【作者基本信息】 西北农林科技大学 ， 植物病理学， 2012， 博士

【摘要】 毛壳科Chaetomiaceae真菌是一类分布非常广泛的资源子囊菌。该类真菌大多数种类都能产生纤维素酶、木聚糖酶、漆酶等，降解纤维素和木质素，许多种类具有产生生物活性物质的能力,可有效抵御肿瘤细胞、作为生物防治材料，少数种类能够引起木本植物病害和人的病害，因此，开展毛壳菌分类研究，对有效利用这类资源具有重要的理论意义。本研究在陕西、新疆、北京、甘肃、内蒙、西藏等17个省市的局部地区采集多种植物残体1139份，不同生态环境土壤表层样品及动物粪便196份。采用形态分类和多基因系统发育相结合的研究策略，对采集分离自我国部分地区的毛壳菌资源，进行了较系统的形态学分类，进一步地通过28S rDNA序列、18SrDNA序列、rDNA-ITS序列、EF-1α序列和细胞色素b (cytb)基因序列，从多基因水平开展了分子系统学分析，探索了毛壳科成员属间和种间的系统发育关系，分析了主要形态性状与系统发育之间的关系，同时对形态学分类结果从基因水平进行了验证。本研究主要取得以下研究成果：1、经过分离，获得的139个毛壳菌菌株，根据形态学性状，对这些菌株进行了分类鉴定，结果显示，它们分属毛壳科Chaetomiaceae的毛壳属Chaetomium、无毛毛壳属Achaetomium和棒囊壳属Corynascus的19个种类，其中毛壳属Chaetomium16种，无毛毛壳属Achaetomium2种，棒囊壳属Corynascus1种。共发现新种4个，国内新记录种3个，建立新组合28个。在所分离鉴定出的毛壳菌类群中，球毛壳Ch. globosum为优势种群，占总量的61.87%，其次为旋丝毛壳Ch. bostrychodes和墙毛壳Ch. murorum，分别占7.91%和5.76%。对毛壳属Chaetomium新种北疆毛壳Ch. beijiangensis sp. nov.和赤峰毛壳Ch. chiifengensis sp. nov.；无毛毛壳属Achaetomium新种小孢无毛毛壳A. microsporum sp.nov.和星无毛毛壳A. stellatis sp. nov.进行了鉴定描述。2、采用28S rDNA基因序列、18S rDNA基因序列、rDNA-ITS基因序列、cytb序列和EF-1α基因序列，研究了毛壳科Chaetomiaceae真菌的系统发育关系，证实毛壳属Chaetomium （含法氏壳属Farrowia）、无毛毛壳属Achaetomium、棒囊壳属Corynascus、梭孢壳属Thielavia、毛喙壳属Chaetomidium为毛壳科Chaetomiaceae成员。18S rDNA基因序列、28S rDNA基因序列和rDNA-ITS序列系统发育树一致显示，毛壳属Chaetomium、毛喙壳属Chaetomidium、梭孢壳属Thielavia都不属于单元演化群。表明现行毛壳科Chaetomiaceaee属级单元分类系统不能正确反映其自然演化关系，建议重新建立属间分类标准关系，并对属的界限进行定义。3、多基因序列系统发育树显示：毛壳菌子囊果的形状和子囊孢子的形状与分子系统发育间密切相关，可以作为分属的主要依据；毛壳菌在培养过程中产生的泌溢物及色泽也与系统发育之间有一定的关系；而子囊果孔口的有无、附属丝类型与着生方式及子囊的形态与属级单元间关系不大，不应该作为属级分类的性状。4、综合形态学特征和多基因序列系统发育性状，发现毛喙壳属Chaetomidium和梭孢壳属Thielavia，在子囊果、子囊、子囊孢子、果壁组织类型等方面与毛壳属Chaetomium相似，属于无孔口的毛壳属类型，据此，将毛喙壳属Chaetomidium和梭孢壳属Thielavia与毛壳属Chaetomium合并，并对毛壳属Chaetomium属的概念进行了重新定义。5、28S rDNA基因序列、rDNA-ITS序列、EF-1α基因序列和cytb基因序列系统发育树都显示球毛壳Ch. globosum不同菌株核苷酸序列存在很大变异，在系统发育树中处于多个不同分支中，表现为非单元演化群，表明根据目前种级分类标准划分的球毛壳Ch. globosum实际是一复合群，可能隐含多个不同的种类。6、角毛壳Ch. caprinum Bainier与旋丝毛壳Ch. bostrychodes在栅栏状细胞结构和培养性状方面明显不同，在多基因序列发育树中它们也处于不同的分枝中，应该作为两个独立的种，建议将角毛壳Ch. caprinum从旋丝毛壳Ch. bostrychodes中分离出来，恢复其早期独立的种的地位。7、毛壳科真菌rDNA-ITS基因和EF-1α基因序列具有相当的变异，基因进化速率适中，种间变异程度较大，种内又有一定保守性，是合适的分子标记类型，藉此可准确方便地进行毛壳菌种内和种间的分类。而cytb基因序列保守性强，对种间的区分能力不强，不建议将之作为种间系统发育研究的性状。更多还原

【Abstract】 The fungi of Chaetomiaceae are widely distributed resource ascomycetes. Most of themcan produce cellulase, xylanase and laccase to decompose cellulose and lignin, and somespecies with the ability to produce biologically active substances which are effective againsttumor cells and as biocontrol materials, a few kinds can cause woody plant diseases or skindiseases for human being. The classification of Chaetomiaceae has an important theoreticalsignificance for effective utilization of such resources.In this study,1139plant residues, and196soil surface samples and animal feces indifferent ecological environment were collected in the17provinces including Shaanxi,Xinjiang, Beijing, Gansu, Inner Mongolia, Tibet and oth areas.Combined morphological characters and phylogenetic analysis of18S rDNA gene,28SrDNA gene, rDNA-ITS gene, EF-1α gene and cytb gene, phylogentics relationships havebeen carried out among the members of Chaetomiaceae. The main results as follows.1.139isolated strains were classified based on the morphological characters. There are19species belonging to Chaetomiaceae, among them16species were the members ofChaetomium,1of Corynascus, and the rest of Achaetomium.4new species and3new-recorded species were discovered, and29new combinations of Chaetomiaceae wereestablished in this study. In all the strains, Ch. globosum ranked first, account for61.87%ofthe total, the numbers of Ch. bostrychodes and Ch. murorum were the second, respectivelyaccount for7.91%and5.76%. The four new species, which were Ch. beijiangensis sp. nov.,Ch. chiifengensis sp. nov., A. microsporum sp. nov. and A. stellatis sp. nov., have beenidentified and described.2. Based on the phylogenetics analysis of18S rDNA gene,28S rDNA gene, rDNA-ITSgene, EF-1α gene and cytb gene, the phylogenetic relations among the species ofChaetomiaceae have revealed, in which the species of Chaetomium, Achaetomium,Corynascus, Thielavia, and Chaetomidium should be members of Chaetomiaceae. Thephylogenetic trees of multi-gene sequences revealed that Chaetomium, Thielavia, andChaetomidium did not belong to a evolution of single-source phylogenetically. Theclassification at present in genus level in Chaetomiaceae could not reflect natural phylogenetic relationships. New criteria for genus level in Chaetomiaceae should beestablished.3. The phylogenetic analysis of multi-gene sequences revealed that there was a closerelationship between the shape of ascoma/ascospores and molecular phylogeny. Therefore,the shape of ascoma and ascospores can be used as the main basis for the establishment of thegenera. The secretions and their color when the species were trained in petri dishes hadsomething to do with the phylogeny. The orifice of ascoma, the types and distribution of hair,and the shape of asci had nothing to do with the phylogeny. They should not be treated astraits for generic classification4. The morphological characteristics and multi-gene sequence phylogenetic traits revealedthat there were similar morphological characteristics in their ascomata, asci, ascospores andhairs among Chaetomium, Thielavia and Chaetomidium. Thielavia and Chaetomidium werethe same as Chaetomium of non-ostiolate. Based on the supporting of morphologicalcharacteristics and multi-gene sequences, Chaetomium, Thielavia and Chaetomidium shouldbe merged to form a new genus taxon. Chaetomium newly should be re-defined and re-described.5. The multi-gene sequence phylogenetics showed that there were different nucleotidesequence in the different strains of Ch. globosum. The different strains of Ch. globosum, non-single evolution group, were in the different branches of the phylogenetic trees. Present Ch.globosum is a species complex including different species.6. Ch. caprinum Bainier and Ch. bostrychodes were highly different in the palisade cellstructure and culture traits. They were also in the different branches of the multi-genesequence phylogenetic trees. Therefore Ch. caprinum Bainier and Ch. bostrychodes should beclassified in two species and restored its early independent status of species.7. There were considerable variation of the gene sequences of rDNA-ITS and EF-1α geneof Chaetomiaceae. Both of them could be used for phylogenetics of the group. Cytb genesequences is conserved in some extend between species, is not recommended as a kind of traitof the interspecific phylogenetic studies.更多还原