南方红豆杉内生真菌的多样性与群落结构

从南方红豆杉480个针叶与枝条组织块中分离到628株内生真菌，根据形态特征和ITS序列鉴定为28属43个分类单元.其中，包括10种丝孢菌、20种腔孢菌、12种子囊菌和1种未知真菌，茎生拟茎点霉为优势种；根据相对频率，链格孢、出芽短梗霉、博宁刺盘孢、盘长孢状刺盘孢、黑附球菌、Fungal sp.、砖红镰孢、围小丛壳、Magnaporthales sp.、稻黑孢、斑点拟盘多毛孢、小孢拟盘多毛孢、Peyronellaea glomerata和Xylaria sp.1等在南方红豆杉中比较常见.南方红豆杉受到内生真菌侵染的程度较高，81%的组织有内生真菌存在，其资源丰富并具有较高的物种多样性；内生真菌分布受组织性质影响，南方红豆杉针叶中内生真菌的定植率、丰富度、多样性明显低于枝条，枝条间内生真菌组成比针叶与枝条间更加相似，表现出组织偏好性或专一性；组织年龄影响内生真菌的群落结构，随着南方红豆杉枝条组织年龄的增长，内生真菌的定植率、丰富度、多样性均表现出逐渐增加的趋势.系统研究南方红豆杉内生真菌的多样性与群落结构，阐明内生真菌在植物组织中的分布规律，可以为南方红豆杉内生真菌的开发利用提供基础资料和科学依据；探讨病原真菌在健康植物组织中的存在情况，对于南方红豆杉的植物资源保护具有积极意义.

Diversity and community structure of endophytic fungi from Taxus chinensis var. mairei.

A total of 628 endophytic fungi were isolated from 480 tissue segments of needles and branches of Taxus chinensis var. mairei. According to morphological characteristics and ITS sequences, they represented 43 taxa in 28 genera, of which 10 Hyphomycetes, 20 Coelomycetes, 12 Ascomycetes and 1 unknown fungus. Phomopsis mali was confirmed as the dominant species. In accordance with relative frequency, Alternaria alternata, Aureobasidium pullulans, Colletotrichum boninense, C. gloeosporioides, Epicoccum nigrum, Fungal sp., Fusarium lateritium, Glomerella cingulata, Magnaporthales sp., Nigrospora oryzae, Pestalotiopsis maculiformans, P. microspora, Peyronellaea glomerata and Xylaria sp.1 were more common in T. chinensis var. mairei. T. chinensis var. mairei were severely infected by endophytic fungi. Endophytic fungi were found in 81 percent of plant tissues with a high diversity. Distribution ranges of endophytic fungi were influenced by tissue properties. The colonization rate, richness, diversity of endophytic fungi in needles were obviously lower than in branches, and kinds of endophytic fungi between branches were more similar than those in needles, thus endophytic fungi had tissue preference. In addition, tissue age influenced the community structure of endophytic fungi. The elder branch tissues were, the higher colonization rate, richness, diversity of endophytic fungi were. Systematic studying the diversity and community structure of endophytic fungi in T. chinensis var. mairei and clarifying their distribution regularity in plant tissues would offer basic data and scientific basis for their development and utilization. Discussing the presence of fungal pathogens in healthy plant tissues would be of positive significance for source protection of T. chinensis var. mairei.