【作者】 杨红；

【导师】 刘志恒； 吕国忠；

【作者基本信息】 沈阳农业大学 ， 植物病理学， 2009， 博士

【摘要】 真菌是土壤中重要的微生物资源,是土壤生态系统物质循环的主要物质基础。森林土壤与农业土壤相比,多呈酸性,加之其相对特殊的生态环境,更利于真菌的生长与繁殖,因此,对森林土壤真菌生物多样性的研究具有重要意义。长白山自然保护区是目前整个欧亚大陆生态系统保存较完整的生态体系,复杂多变的自然环境,使得保护区内蕴藏着极其丰富的生物资源。长白山北坡因其明显的海拔差异、气候变化、植物垂直分布和土壤特征等综合因素的影响,北坡地带的植物、动物、微生物具有明显的区系分布特点。通过对长白山北坡森林土壤中真菌的分类研究,可明确其物种种类、种群数量及其多样性分布规律,为长白山自然保护区微生物资源的合理开发和利用,以备筛选出具有一定应用价值的食用、药用、工业用等有益真菌提供科学的理论依据。2006年至2008年,分别于不同时期(6月、7月、8月)赴长白山自然保护区北坡森林地带采集土壤标样。根据海拔高度、森林类型及土壤类型等因素,选取6处能代表不同海拔高度和生态类型的地点,采用“之”字形多点采样法采集土壤样品共计360份。对土样同时采用稀释平板法和土壤平板法进行真菌分离和培养,共获得932株真菌。根据形态特征,鉴定出53属108种真菌,其中接合菌9属13种,子囊菌9属17种,无性型真菌35属78种。108种真菌中包括中国新记录属1个,即小裸囊壳菌属Gymnascella;中国新记录种7个,即短毛毛壳Chaetomium brevipilium、丹喀小裸囊菌Gymnascella dankaliensis、条纹孢蔓毛壳Herpotrichia striatispora、冬青生柱枝孢Cylindrocladium ilicicola、棘枝粉孢Oidiodendron echinulatum、淡黄茎霉Phomaflavescens、柱孢弯颈霉Tolypocladiumn cylindrocladium。论文对已鉴定的真菌,对种的阶元均作了形态描述及生境记录,并附有显微形态图;对部分重要属、种进行了简要的分析和讨论;对不同门下分离获得不同的真菌种类及分离所获的部分优势属分别编制了分类检索表。研究发现海拔高度、森林类型、植被垂直构成、气候条件及土壤类型对长白山森林土壤真菌种群的组成、数量及多样性分布均具有一定的影响,具体结果如下:不同海拔高度样地中的土壤真菌的种群组成之间具有较大的差异。在海拔800米与海拔1200米处,气候温湿,林分复杂,土壤养分丰富,因此,较适于真菌的生存与繁殖;而在海拔2100米处的高山苔原带,气候湿冷,植被单一,土层瘠薄,此海拔处的恶劣环境不适于真菌的生存。青霉属(Penicillium)、曲霉属(Aspergillus)真菌是6个不同海拔样地中始终排在前两位的代表优势属。森林类型对土壤真菌种群的组成、数量及分布具有一定的影响,即表现出从针阔叶混交林至高山苔原带,真菌的种群数量呈现出逐渐递减的变化趋势。青霉属(Penicillium)、曲霉属(Aspergillus)、木霉属(Trichoderma)、根霉属(Rhizopus)真菌是4个不同林型下的代表优势属。研究结果表明,随着海拔的升高,相邻两个林型间相似性系数逐渐升高,且针阔叶混交林带与苔原带不但在植被组成上有很大的差异,而且在空间距离和海拔高度上也相差最远,所以其真菌种类表现出最低的相似性,说明了生态环境的多样性对真菌分布格局存在直接影响。同一林型下气候明显差异的不同月份,林下土壤真菌物种种类及数量表现较一致的变化规律,即7月＞8月＞6月:不同林型间的同一月份真菌数量变化趋势基本一致,即针阔叶混交林＞针叶林＞岳桦林＞高山苔原,说明气候条件影响土壤真菌种群及数量组成。另外,研究发现不同土壤类型演替中真菌种类及数量的分布依次为暗棕色森林土＞棕色针叶林土＞山地生草森林土＞山地苔原土,说明了土壤真菌分布受土壤类型的分布影响较大。更多还原

【Abstract】 Fungi are the important components of soil microorganisms and they play a significant role in material cyclization in soil ecosystem.The forest soil is characterized with lower acidity by comparison with agricultural soil.Due to the special ecological environment it is more favorable to fungal growth,so it is rich in fungal species.The fungal diversity in forest soil is a fascinating work.Changbai Mountain Natural Reserve is one of the integratedly conserved ecosystems in European-Asian continent.The complicatedly changing natural environment enriches Changbai Mountain with plentiful bio-resources.The north slope of the mountain is characterized with evident elevation difference,climate variation,vertical distribution of vegetation and different soil types.It is recorded that the animals,plants and microorganisms in the north slope of the mountain exhibit clear regional distribution characteristics.The study of soil fungi in the north slope of Changbai Mountain based on classification was designed to explore the fungal resources and their population and biodiversity,it will help provide a scientific base for the utilization of the soil fungi.During June and August in 2006,2007 and 2008,six sampling locations with different elevations,forest types and soil types were selected in the north slope of Changbai Mountain, 360 forest soil samples were collected by zigzag route in each sampling sites.By means of the methods of dilution plate and soil plate,nearly 1000 fungal isolates were obtained.Based on morphological characteristics,these fungal isolates were identified as 108 species of 53 genera,including one newly recorded genus and five newly recorded species for China.Of the these fungal species,13 species of 9 genera are zygomyctes,17 species of 9 genera ascomyctes and 78 species of 35 genera anamorphic fungi.The newly recorded genus was Gymnascella,the seven newly recorded species were Chaetomium brevipilium,Gymnascella dankaliensis,Herpotrichia striatispora,Cylindrocladium ilicicola,Oidiodendron echinulatum, Phoma flavescens and Tolypocladiumn cylindrocladium.The morphological description, habitat,and micrograph for every fungal species were provided in the paper.Parts of fungal genera and species were briefly analyzed and discussed.The study indicates that the composition,quantity and distribution of fungal populations were associated with elevations and forest types.The fungal populations in tested soil samples at elevation 800m and 1200m were plentiful because of the warm and moist climate,luxuriant nourishment,while the those fungal populations at 2100m were significantly decreased because of the cold and moist climate,poor vegetation and infertile soil.The species of Penicillium and Aspergillus were the predorminant fungi in the soil sampling locations at six different elevations.The fungal populations were decreased from the coniferous and broad-leaved forests zone up to the tundra land zone of the mountain.Penicillium,Aspergillus,Trichoderm, Rhizopus were the dominant genera in the four different forest types.The similarity coefficients of fungal populations in adjacent forest types were much closer. The difference between the similarity coefficients of fungal populations in the coniferous and broad-leaved forests zone and the tundra land zone were much greater possiblely due to their significant discrepancies in vegetation composition,altitudes and spacial distance.The research results suggest that the diverse environments in the mountain had an evident effect on the distribution patterns of the forest soil fungi.It is found that climate conditions in the mountain affected the diversity of the soil fungi. The developing trend of the quantity of the soil fungal populations and compositions in each forest type was July＞August＞June.On the other hand,the developing trend of the composition and quantity of the soil fungal populations in the same month were coniferous and broad-leaved forest＞dark coniferous forest＞Betula ermanii forest＞tundra land zone.The research results show that the soil types in the mountain also had an evident effect on the fungal distribution and composition in different types of forest soil.The effect of soil types in the north slope of Changbai mountain was similar to the factors such as forest types, vegetation and climate with the similar trend of fungal population and composition,namely, coniferous and broad-leaved forest＞dark coniferous forest＞betula ermanii forest＞tundra land zone.更多还原