东北地区羊耳蒜根部内生真菌多样性研究

Diversity of Endophytic Fungi in Roots of Wild Liparis japonica in Northeast China

兰科植物的生长发育离不开其根部内生真菌的共生。为探明羊耳蒜(Liparis japonica)根部内生真菌种类和多样性规律,选取东北地区7个不同地理种群的羊耳蒜植株进行根部内生真菌的分离、培养,根据形态特征和ITS序列进行种类鉴定及其多样性与环境因子的相关性分析。共分离到内生真菌9个类群201个菌株,其中大部分菌株属于Tulasnella和Sordariomycetes真菌,在所调查的地理种群中均有分布,而其余7类真菌为稀有属。不同地理种群羊耳蒜根部内生真菌的多样性无显著差异,但CBS种群分离得到的真菌类群较少。各地理种群根部内生真菌的类群数量和多样性均与羊耳蒜株高呈显著正相关,推测内生真菌种类越丰富对宿主的促生作用越明显。而Tulasnella真菌作为目前公认的兰科菌根真菌,其相对多度受环境因子影响较小,在一定程度上验证了该类真菌在土壤中存在的广泛性及与宿主羊耳蒜共生的专一性。结论认为东北地区羊耳蒜根部内生真菌资源丰富,并能与宿主形成良好的共生关系。

The endophytic fungi growing in roots of orchids species are necessary for orchids’ growth and development. In order to understand the endophytic fungi in roots of Liparis japonica, we selected seven populations of L. japonica in Northeast China to isolate and identify the endophytic fungi by morphological and r DNA ITS sequence analysis and conducted analysis of their relationships with soil factors. A total of 201 fungal isolates belonging to nine groups were obtained, most of which were species of Tulasnella and Sordariomycetes and were distributed in all populations of the plant. The other seven groups belong to rarely isolated fungi. There was no significant difference among the endophytic fungal diversity in different plant populations except for CBS population. It was found that significant positive relationships were present between the group number, diversity and the height of L. japonica plants, suggesting that the higher the endophytic diversity was, the better the hosts’ growth. However, as the well-known endophytic mycorrhizal fungi of orchids species, the genus of Tulasnella were weakly affected by environmental factors, indicating that this fungus was widely distributed in soils, and it was specifically associated with roots of L. japonica.The results showed abundant resources of endophytic fungi in roots of wild L. japonica and well symbiotic relationships with host in Northeast China.