广西北部湾红树植物内生真菌多样性

Diversity of endophytic fungi in mangrove plants of Beibu Gulf, Guangxi

摘要:

【目的】研究广西北部湾地区红树植物内生真菌多样性，建立北部湾红树植物内生真菌种质资源库，为利用内生真菌生物技术促进农业可持续发展提供理论依据。【方法】从广西北部湾地区采集红树植物组织样本，采用表面消毒法分离真菌，通过测定分离菌株对宿主植物是否具有致病性来筛选内生真菌，结合形态学特征和分子生物学分析对内生真菌进行分类与鉴定。【结果】从60个红树植物样本中分离得到1 764个菌株，经过致病性测定筛选获得41株内生真菌，分离率为2.3%。其中从宿主植物红海榄分离得到15株内生真菌，占总菌株数的36.6%，比例最高。通过分析，发现这些内生真菌在ITS-NJ、NS-NJ两个系统发育树上各聚为7个大分支，分属8个科(目)。其中球腔菌属Mycosphaerella、德福里斯孢属Devriesia、假尾孢属Pseudocercospora、枝孢霉属Cladosporium、Pleosporales等属(科)真菌是广西红树林的优势菌。【结论】广西北部湾地区红树植物内生真菌菌种资源丰富。

Abstract:

[Objective] To discover the diversity of endophytic fungi and establish its germplasm bank in mangrove plants of the Beibu Gulf of Guangxi, and provide the theoretical basis for using the endophytic fungi biotechnology to promote agricultural sustainable development. [Methods] Mangrove tissue samples were collected from Beibu Gulf, the fungi were isolated by surface disinfection method and screened by determining whether the isolates were pathogenic to the host plants, and the endophytic fungi were classified and identified according to the morphological characteristics and molecular biological analyses. [Results] The results showed that 1 764 isolates were obtained from 60 mangrove plant tissue samples, and 41 endophytic fungi were screened by pathogenicity test. The isolation rate of endophytic fungi was 2.3%. Among them, 15 endophytic fungi were isolated from the host plant Rhizophora stylosa, accounting for 36.6% of the total strains with the highest proportion. The results showed that these endophytic fungi were clustered into seven branches both in ITS-NJ and NS-NJ phylogenetic trees, belonging to 8 families/orders. Mycosphaerella, Devriesia, Pseudosercospora, Cladosporium and Pleosporales are the dominant fungi of mangrove in Guangxi. [Conclusion] There is a wide variety of fungal species in mangrove plants of Beibu Gulf, Guangxi.