红树林生态系统中不同生境不同深度土壤的可培养真菌的多样性

Diversity of culturable soil fungi in different habitats and depths in mangrove ecosystem

摘要:

【目的】了解八门湾红树林生态系统中不同生境(潮间带、海洋到红树区的过渡带、海桑红树区)和不同深度土壤的可培养真菌的多样性。【方法】采用稀释涂布平板法分离土壤中的真菌，利用形态学观察和ITS rDNA序列分析技术研究可培养真菌的表观和遗传多样性。【结果】从八门湾红树林生态系统的3个不同生境中分离到257株真菌，分别属于21属28种，其中青霉属(Penicillium)、曲霉属(Aspergillus)和木霉属(Trichoderma)为优势类群。来自不同生境或者同一生境不同采样深度的土壤真菌种类组成不同，并且有些真菌类群只出现在特定的样品中。从空间角度看，红树区土壤样品的真菌多样性高于其他两个生境的土壤样品；从垂直角度看，潮间带和过渡带的表层土壤样品的真菌多样性高于深层土壤样品，而红树区的深层土壤样品真菌多样性高于表层土壤样品。【结论】八门湾红树林生态系统中的可培养真菌资源丰富，种类多样性较高，但不同生境或不同深度的可培养真菌分布存在较大的差异。这些结果揭示了红树林土壤中可培养真菌的生态分布特点，也为红树林真菌资源的开发利用提供了基础的背景资料。

Abstract:

[Objective] To understand the diversity of culturable fungal resource isolated from soil in different habitats (intertidal zone, transitional zone from sea to mangrove, mangrove forest zone) of mangrove ecosystem. [Methods] Diluted sediment suspensions were spread on plates to isolate fungi. The phylogenetic and genetic diversity of fungal isolates was analyzed using morphology and ITS rDNA sequences, respectively. [Results] In total 257 fungi belonging to 21 genera and 28 species were isolated from soils in 3 different habitats of mangrove ecosystem. Penicillium, Aspergillus and Trichoderma were the dominant fungal populations. Fungal populations from different habitats or different depths were different. Spatially, diversity index from the mangrove forest zone were higher than those from the other two habitats; vertically, diversity index of surface-layer samples were higher than those of deep-layer samples in intertidal and transitional zones, while diversity index of deep-layer samples were higher than those of surface-layer samples in mangrove forest zone. [Conclusion] The ecological distribution characteristics of culturable soil fungi in mangrove ecosystem provided background data of fungal resource for us to explore potential applications.