兰科植物菌根真菌研究新见解

New insights into orchid mycorrhizal fungi research

兰科(Orchidaceae)在地球生命系统演化中占有十分重要的地位,几乎全部兰科植物均处于不同程度的濒危状态,研究兰科菌根真菌对于保护珍稀濒危兰科植物具有重要意义。该文在对菌根真菌相关的概念及研究方法进行综述的基础上,对兰科菌根真菌的主要类群、特异性及其与兰科植物稀有性之间的关系,以及兰科菌根真菌与兰科植物之间的营养关系和进化关系进行了总结。兰科菌根真菌的研究方法可以归纳为经典研究方法、早期分子生物学方法、rDNA片段高通量测序法、宏基因组学方法。兰科菌根真菌类群主要隶属于担子菌门(Basidiomycota)、子囊菌门(Ascomycota)和毛霉门(Mucoromycota)。根据兰科菌根真菌特异性与否,首次明确了兰科菌根真菌定植关系可分为三大类:特异性定植、广泛性定植和特异-广泛兼性定植。根据营养关系特点,首次将兰科植物与菌根真菌之间的营养关系划分为三大类:兰花单向利好型、典型共生型、分工合作型。兰科菌根真菌特异性与兰科植物稀有性之间的关系呈现出两面性,而兰科菌根真菌与兰科植物之间是否存在协同进化关系还需要更多的研究才能阐明。此外,该文还对兰科菌根真菌领域今后的研究提出了一些思路。

Orchidaceae occupies a very important position in the biological phylogeny and evolutionary system on the earth.Almost all Orchidaceae species are threatened or endangered to certain degrees.It is of great significance to study orchid mycorrhizal fungi(OMF)to protect rare and endangered orchids.In this article,OMF and its related terms were introduced.The methods used for the OMF research were summarized.The main taxa and specificity of OMF,the relationship between OMF specificity and orchids rarity,the nutritional relationship and co-evolutionary relationship between OMF and orchids were reviewed.The OMF research methods mainly include:classical methods,early molecular biological methods,rDNA fragment high-throughput sequencing methods and metagenomic methods.The taxa of OMF mainly belong three fungal phyla:Basidiomycota,Ascomycota and Mucoromycota.According to the degree of OMF specificity,it is the first time that we put forward that the OMF colonization can be divided into three types:specific colonization,extensive colonization and specific extensive facultative colonization.According to the characteristics of the nutritional relationship,we first put forward that the nutritional relationship between orchids and OMF can be divided into three types:orchids unidirectional benefit type,typical symbiotic type and cooperation type.The correlation between OMF specificity and orchids rarity showed two sides.And more researches are still needed to clarify whether there is co-evolutionary relationship between orchids and OMF.Finally,some ideas based on the current researches were proposed for future OMF research.