兰科植物种子共生萌发真菌多样性及共生萌发机制研究进展

自然环境下,兰科植物种子细小无胚乳,需要和适宜的真菌共生才能萌发,因而与真菌有天然的共生关系。自身繁殖率低加之近年来栖息地环境破坏导致兰科植物资源更加濒危,而通过筛选适合的真菌进行种子的共生萌发可以有效地实现兰科植物的种质保育及濒危种类野生居群的生态恢复。本文对地生型、附生型以及腐生型等兰科植物已发现的萌发真菌的多样性进行了系统地梳理,发现担子菌门的胶膜菌科、角担菌科以及蜡壳耳目真菌为已报道共生萌发真菌的主要类群;同时对兰科植物种子的共生萌发机制,包括形态学机制、营养机制和分子机制等方面的相关研究进行了归纳论述,但是当前关于兰科植物和真菌互作机制方面的研究还相对较少,许多问题需要进一步明确。本文对共生萌发真菌在兰科植物保育和繁育中的应用以及共生萌发机制的研究等方面具有一定的参考价值。

Fungal diversity and mechanisms of symbiotic germination of orchid seeds: a review

For lack of endosperm, tiny orchid seeds need the aid of suitable fungi during germination, and therefore the natural mycorrhizal symbiosis comes into being. Low reproduction rate and ruined habitat environment in recent years endangered orchid resource increasingly. For protection of endangered orchid resource and recovery of ecological diversity, screening symbiotic fungi with capacity for helping germination of orchid seeds is in urgent need. In this paper, investigation of orchid symbiotic fungi with different growth type including geobiontic type, epiphytic type and saprophytic type are systematically reviewed. Facts have proved that Tulasnellaceae, Ceratobasidiaceae and Sebacinales, belonging to Basidiomycota, are the main fungal groups performing symbiotic relationship with orchids. The mechanism concerning morphology, nutrition and molecular biology of orchid seed germination is discussed. Researches on mechanism of interaction between symbiotic fungi and orchid seed germination are inadequate and many problems need further exploration. This paper provide reference for applying symbiotic fungi to breeding and protecting orchid resource and exploring mechanism of symbiotic germination.