青檀果内生真菌菌群的组成及多样性

为进一步了解我国古老特有的野生植物青檀内生真菌的组成特征,以安徽琅琊山自然保护区内的野生青檀果为研究对象,采用组织分离和形态学鉴定的方法对青檀果内生真菌进行了分离和鉴定.结果表明: 从500个组织块中共分离内生真菌428株,隶属于3目4科20属,未产孢的菌株暂归为无孢菌群(80株,18.7%).暗梗孢科和球壳孢科是青檀果内生真菌的优势科,分别占38.1%和32.9%,交链孢属和拟茎点霉属为其优势属,分别占27.1%和16.8%.青檀果不同部位内生真菌的组成存在差异,以种子中分离的内生真菌数量最多(19属181株,占42.3%),果翅中分离的内生真菌最少(7属88株,占20.6%).除了交链孢属为3个不同部位的共同优势属之外,拟茎点霉属和大茎点霉属分别是果柄和果翅的优势属.果柄和果翅内生真菌菌群的组成相似性最高(C_S=0.78),种子和果翅的相似性系数最低(C_S=0.50).分析显示,果柄与果翅在内生真菌菌群组成上无显著差异,而种子与果柄、种子与果翅在内生真菌菌群组成上均存在显著差异.

Community composition and diversity of endophytic fungi from the fruits of Pteroceltis tatarinowii.

Endophytic fungi from the fruit of Pteroceltis tatarinowii were studied, to understand the characteristics of microbial community composition on this ancient and peculiar wild plant. Healthy fruits were collected from areas of the natural distribution of P. tatarinowii in Langyashan Natural Reserve, Anhui Province, China. Endophytic fungi were isolated from fruit tissue, and fungal strains were classified on the basis of morphology. From 500 tissue blocks taken from fruit, a total of 428 isolates of endophytic fungi were identified and classified into 20 genera, 4 families, and 3 orders. Eighty strains showed no reproductive structures, and were classified as Mycelia sterilia (18.7%). The dominant families were Dematiaceae and Sphaeropsidaceae, occupying 38.1% and 32.9% of isolates, respectively. Alternaria and Phomopsis were the dominant genera, accounting for 27.1% and 16.8% of isolates. Different parts of the fruit had different compositions of endophytes. The highest number of fungi was isolated from seeds (19 genera, 181 strains, 42.3%), and the lowest from fruiting wings (7 genera, 88 strains, 20.6%). Alternaria was the commonest genus of endophytes, isolated from three different parts of the fruit. Phomopsis and Macrophoma were the dominant genera on carpopodium and fruiting wings, respectively. The communities on carpopodium and fruiting wings were most similar to one another (C_S=0.78), while those on fruiting wings and seeds were least similar (C_S=0.50). Fisher’s exact test showed no significant difference between the compositions of endophytes from the carpopodium and fruiting wings, while significant diffe-rences were observed between communities on seed and carpopodium, and seed and fruiting wings.