紫花苞舌兰不同发育阶段根内及根区土壤真菌的分布特征

Fungal community dynamics in the roots and root zone soil of Spathoglottis plicata at different development stages

摘要:

【目的】分析紫花苞舌兰(Spathoglottis plicata)不同发育阶段根内及根区土壤真菌多样性变化，探索其分布规律，挖掘潜在的真菌资源。【方法】将紫花苞舌兰发育阶段划分为原球茎期、幼苗生长前期、幼苗生长中期、幼苗生长后期、成年期和花期。采用QIIME 2等软件对高通量测序的不同发育阶段根系及根区土壤真菌进行群落组成和多样性分析；利用组织分离法分离原球茎内和幼苗根系真菌，分析其系统发育关系。【结果】紫花苞舌兰根系及根区土壤优势真菌类群不同，分别为胶膜菌科(Tulasnellaceae)和爪甲团囊菌科(Onygenaceae)真菌。紫花苞舌兰不同发育阶段真菌类群存在动态变化，原球茎期至幼苗生长中期，胶膜菌科真菌占绝对优势地位，幼苗后期和成年植株阶段赤壳科(Nectriaceae)和发菌科(Trichocomaceae)真菌占比较高，花期植株根系的优势类群是角担菌科(Ceratobasidiaceae)真菌。此外，原球茎及幼苗根系共分离获得101株真菌，分属13科，胶膜菌科占比35.65%，为优势类群。【结论】本研究揭示了紫花苞舌兰不同发育阶段根系及根区土壤真菌群落组成及多样性变化规律，为深层次理解兰科植物与共生真菌关系及珍稀濒危兰科植物回归地点的选择提供理论依据。

Abstract:

[Objective] To investigate the fungal diversity and community dynamics in the roots and root zone soil of the invasive species Spathoglottis plicata at different development stages and mine potential fungal resources. [Methods] The developmental period of S. plicata was divided into the protocorm, pre-seedling, middle-seedling, late-seedling, adult, and flowering stages. Fungal community composition and diversity in the roots and root zone soil were analyzed by QIIME 2 and other software. Fungal strains were isolated by the tissue culture method from the protocorms and seedlings of S. plicata, and the phylogenetic relationship of the strains was analyzed. [Results] The dominant fungi in the roots and root zone soil of S. plicata were Tulasnellaceae and Onygenaceae, respectively. The fungal community composition of S. plicata varied across different developmental stages. Tulasnellaceae was the most prevalent from the protocorm to middle-seedling stage, while Nectriaceae and Trichocomaceae became dominant during the late-seedling stage and adult stage. At the flowering stage, Ceratobasidiaceae presented high relative abundance. A total of 101 fungal strains were isolated from the protocorms and seedling roots of S. plicata, belonging to 13 families, in which strains of Tulasnellaceae accounted for 35.65%, being dominant. [Conclusion] The present study elucidated the fungal community composition and diversity dynamics in the roots and root zone soil of S. plicata at different development stages. The findings offer a theoretical foundation for comprehensively understanding of the intricate relationship between orchids and symbiotic fungi and facilitating the selection of optimal habitats for the conservation of rare and endangered orchid species.