荒漠植物牛心朴子内生真菌的分离与鉴定

Separation and identification of endophytic fungi from desert plant Cynanchum komarovii

目的:研究荒漠植物牛心朴子内生真菌类群在不同器官中分布的多样性及其与生态环境的关系,并初步筛选牛心朴子具有潜在生物活性的内生真菌。方法:采用PDA培养基,分别对陕西、宁夏野生牛心朴子内生真菌进行分离、纯化;根据菌落的形态特征并结合真菌的ITS序列进行菌株鉴定;采用稻瘟酶模型,初步筛选活性菌株。结果:从牛心朴子中共分离得到内生真菌94株,鉴定为6目9科13属9种,其中宁夏产地47株,根5株,茎14株,叶28株,鉴定为4目5科9属8种;陕西产地47株,其中根16株,茎18株,叶13株,鉴定为4目6科8属5种;18株真菌代谢产物能完全抑制稻瘟霉孢子萌发,其中N4和S17菌株的发酵液病原菌菌丝生长的抑制作用均比较强。结论:荒漠植物牛心朴子内生真菌具有多样性,不同地理环境和组织类型对内生真菌的数量和种群组成存在显著差异;宁夏牛心朴子菌株分布于叶中较多,陕西牛心朴子菌株分布于茎、叶中较多;牛心朴子内生真菌具有显著的抗稲瘟菌活性。

Objective ： The research aimed to investigate the entophytic fungal community of Cynanchum Komarrovii, including the biodiversity in different organs and the correlations with ecological environment. Endophytic fungi with patent bioactivity were also rapidly screened. Method： PDA medium was used to isolate and purify the endophytic fungi from C. komarovii living in Shaanxi and Ningxia district, respectively. The strains were identified based on the morphological characteristics of the fungi and similarity of 5.8S gene and internal transcribed spacer （ITS） sequence. Pyriculaia oryzae model was applied to preliminarily screen the active fungi. Re- sult ： Ninety-four strains of endophytic fungi were isolated and identified to 9 species, 13 genera, 9 families and 6 orders, among them, 47 strains were from the plants living in Ningxia. And then, 5 of them were isolated from roots, 14 from branches, and 28 from leaves. They were identified belonging to 8 species, 9 genera, 5 families and 4 orders. Additionally, 47 strains were from the plants living in Shaanxi. 16 were isolated from the roots, 18 from branches, 13 from leaves. They were identified belonging to 5 species, 8 genera, 6 families and 4 orders. By preliminary screening, 18 strains of endophytes completely inhibited the germination of conidium, which showed a potential bioactivity for these fungi. Both N4 and S17 strains had stronger growth inhibition effect. Conclusion： Endophytic fungi from desert plant C. komarovii have the feature of diversity. Different geographical environment and type of organizations lead to the significant difference on the quantity and the species composition. Most of fungi in Ningxia C. komarovii distribute in leaves. How- ever, most of those in Shaanxi C. komarovii distribute in stems and leaves. It also indicated that endophytes from C. komarovii had a strong antifungal activity.