【作者】 孙霞；

【导师】 张天宇；

【作者基本信息】 山东农业大学 ， 植物病理学， 2006， 博士

【摘要】 链格孢是半知菌暗色丝孢菌中重要的一类真菌,该属真菌种类多,寄主范围和地理分布广泛。95%以上的种能兼性寄生在植物上,是重要的植物病原菌。有些种是人和动物的条件致病菌,引起多种疾病。有些种可用作杀菌剂、除草剂等,是有应用潜力的生物资源。因此链格孢的正确分类鉴定具有重要的理论和实践意义。然而由于该属真菌受环境条件或培养条件的影响,分生孢子的形态变异幅度较大,仅依靠表形特征为依据的传统分类方法已不能满足需要,必须探索其它分类方法来弥补传统分类的不足。许多研究者从很多方面研究了链格孢的种级分类标准,但是目前在多种分类方法所得到的结论,及这些方法在链格孢种级分类中的作用等方面存在一些争议和混乱,这些现象给链格孢的发展和交流,及应用研究带来了很大影响。本研究的目的就是从传统形态学、生物化学、分子生物学、植物病理学等方面探索一套简便易行的分类方法,以解决目前链格孢分类上存在的一些问题。首先从全国20多个省、自治区、直辖市实地采集近2000份标本,加本实验室、标本室保存的标本共计5000余份,经保湿培养,获得近250个菌株。以分生孢子形态及产孢表型特征为主要分类依据,共描述鉴定链格孢44种,其中,新种7个,新组合1个,中国新记录种5个(见附录),补充描述中国已报道种29个,不确定种2个。蛋白质是基因表达的直接产物,蛋白图谱所表现的构形、净电荷及分子量的不同反映了物种之间的不同。为了从蛋白质水平检测链格孢种间的差异,我们在审慎的形态学鉴定基础上,选用15个菌株进行可溶性蛋白凝胶电泳分析,21个菌株进行酯酶同工酶分析。结果显示,不同种间可溶性蛋白图谱的带型具多型性,种内菌株间的带型具相似性。不同种间的酯酶同工酶带型具多型性,种内菌株间带形基本一致。聚类分析都得到了和形态鉴定一致的结果。表形性状的差异最终是由基因型决定的。RAPD技术用随机引物对整个基因组DNA进行扩增,具有极大的丰富性和探测性。我们用筛选出的9个随机引物对57个链格孢菌的基因组DNA进行RAPD分析,共得到142个多态性带,平均每个引物15.8条带。聚类结果显示,大孢子种和小孢子种能明确区分成两组,小孢子种在42%的相似系数处,更多还原

【Abstract】 Alternaria is a dematiaceous mitosporic fungus with a wide variety of habitats and geographical distribution. More than 95% species are very important plant pathogens, some species can cause human and animal diseases, and some are potent biological resources. So there are theoretic and practical significances for Alternaria correct classification and identification.However, conidial morphology is highly variable due to the environment and culture condition. The morphology-based taxonomic method has not been met the demands, so we need seeking other taxonomic methods to compensate the deficiency. To date, many mycologists study the taxonomic criteria at Alternaria species level by many means, but there are some confusion and divergent views. All of these affect Alternaria development, communication and application. The aim of this study is to seek reliable and valuable taxonomy methods by morphological, biochemical, molecular biological and phytopathological means to resolve the problems.We had collected more than 2000 specimens from more than 20 provinces. From these collections and another 3000 herbarium specimens identified, we gain about 250 isolates. Based on the conidial and sporulation pattern characters, we described and illustrated 44 Alternaria taxa. Among them, there are 7 new species, 1 new combination, 5 Chinese newly recorded species (see addendum), 2 uncertain species, and 29 reported species from China. Proteins are the direct products of gene. In order to test the interspecies difference from protein level, we chose 15 Alternaria isolates with polyacrglamide gel electrothoresis of soluble protein analysis, and 21 isolates with esterase isozyme analysis. Results show that the protein pattern is polymorphic of interspecies. The EST isozyme pattern is polymorphic of interspecies, while it is relatively homogeneous of intraspecies. Cluster analyses with UPGMA are corresponded with morphological identification.更多还原