西双版纳、白茫雪山、波罗的海南岸地衣纯培养放线菌多样性

Diversity of cultivable actinomycetes associated with lichen of Xishuangbanna, Baimang Snow Mountain, and South Bank of the Baltic Sea

摘要:

【背景】在地衣共生系统中除了共生真菌、藻类以外，还蕴藏着丰富的放线菌资源。【目的】采集来自云南西双版纳、白茫雪山、德国波罗的海南岸3个地区的地衣，对获得的地衣纯培养放线菌进行多样性分析。【方法】采用3种放线菌选择分离培养基，通过平板稀释涂布法分离放线菌。通过比较16S rRNA基因序列相似性以及构建系统发育树，确定纯培养放线菌的分类地位。【结果】共分离菌株1 123株，鉴定417株。其中从西双版纳17份地衣样品中分离纯化到107株放线菌，分布在7个目14个科33个属，潜在新种18株，其中链霉菌为优势菌属；从白茫雪山7份地衣样品中分离纯化到103株放线菌，分布在4个目5个科9个属，潜在新种16株。其中链霉菌为优势菌属，占比39%；从波罗的海南岸5份地衣样品中分离纯化到65株放线菌，分布在4个目8个科18个属，潜在新种5株，潜在新种菌和链霉菌为优势菌属。【结论】在本研究条件下，西双版纳可培养地衣放线菌多样性较白茫雪山和波罗的海南岸丰富。白茫雪山地衣链霉菌居多，潜在新种占比15.5%。3个地区地衣放线菌的区系组成各不相同，这与3个地区地衣所处地理环境、完全不同的气候密切相关。

Abstract:

[Background] Apart from symbiotic fungi and algae, the lichens symbiosis system also includes some symbiotic actinomycetes. [Objective] To collect lichen samples from Xishuangbanna, Baimang Snow Mountain of Yunnan and South Bank of the Baltic Sea in Germany, and to analyze the diversity of pure cultivate actinomycetes associated with lichens. [Methods] Three actinomycetes selective media were used to isolate actinomycetes through plate dilution method. The taxonomic status of pure cultured actinomycetes was determined by comparing 16S rRNA gene sequence similarity and constructing phylogenetic tree. [Results] A total of 1 123 strains were isolated and 417 strains were identified. Among them, 107 strains of actinomycetes, including 18 potential new taxa, were isolated and purified from 17 lichen samples of Xishuangbanna which distributed in 7 orders, 14 families and 33?genera. Streptomyces was distributed widely. One hundred and three actinomycetes were separated from 7 lichen samples of Baimang Snow Mountain which belonging to 4 orders, 5 families and 9 genera. Sixteen possible new species were acquired. Streptomyces was the dominant genus, accounting for 39% of the total number of the actinomycetes. Total 65 strains of actinomycetes were obtained from 5 lichen samples of South Bank of the Baltic Sea which distributed among 4 orders, 8 families and 18 genera. Five potential new taxa and Streptomyces were the prime group. [Conclusion] In this study, the diversity of actinomycetes associated with lichens in Xishuangbanna was more abundant than Baimang Snow Mountain and South Bank of the Baltic Sea. Members of streptomycetes were predominant, and potential new taxa accounting for 15.5% of total actinomycetes associated with lichens in Baimang Snow Mountain. The floristic composition of actinomycetes associated with lichens in the three regions was different, which was closely related to the geographical environment and completely different climate of the three regions.