Preliminary Studies Of Lobaria Bacterial Community

Lichen is a composite organism that arises from algae living among filaments of multiple fungi in a symbiotic relationship.lichens are not plants without true root stem and leaf,often can survive in the harsh conditions,known as “pioneers of plant Kingdoms ” have high scientific and medicinal values.To data there are a large number of endophytic fungi and bacteria found in lichen,symbiotic bacteria provide nutrition,nitrogen source,resistance to biotic and abiotic stress for lichen,and becomes more and more important.However,the distribution characteristics and the mainly factors remain to be studied.For the first time in this experiment,25 samples' non-photosynthetic bacteria of Lobaria were collected from four different sites using the Illumina Miseq platform for high throughput sequencing.25 specimens were taken from: Yunnan Laojunshan six samples,Sichuan Gagongshan Nature Reserve two places six samples per location,and Yunnan Ailao Mountain seven samples.The Mothur software package and the Linux-based FLASH and QIIME software packages are used to process the massive data obtained by sequencing.A total of 966653 effective sequences were obtained after 25 samples,and 392509 were obtained from the photosynthetic symbiotic bacteria in the four samples.The average number of each samples was 15,700,accounting for 40.60% of the effective sequences of the each samples.The abundance of photosynthetic symbiotic bacteria in all the samples was more than half,and the non-photosynthetic bacteria community was studied in this experiment,so we removed the sequence of photosynthetic symbiotic bacteria in the later data processing.Twenty-five samples were identified by OTU classification and classification status,there are eleven bacteria phylum,namely: Proteobacteria?Firmicutes,?Acidobacteria,?Bacteroidetes ?Planctomycetes,?Actinobacteria,?Armatimonadetes,?Verrucomicrobia,?Gemmatimonadetes,?Chloroflexi?WPS-2.Proteobacteria have absolute advantage in the average proportion of more than 50% in 25 samples,accounting for absolute advantage.Rhizobiales is the dominant group at the level of Order;Acetobacteraceae is the dominant group at the level of Family;The highest group is not named at the level of Genus,indicating that there are many undeveloped new species of bacterial.There were no differences between the four groups,for the highest abundance of group at level of Phylum and Order.The highest abundance of the Phylum is Proteobacteria,The average abundance of each sample in the group was: 49.58% in group A,54.38% in group B,56.15% in group C,54.09% in group D.At the level of Order the highest abundance is Rhizobiales,The average abundance of each sample in the group was: 21.27% in group A,18,23% in group B,22.56% in group C,26.96% in group.At the level of Family,the highest abundance of the six specimens collected from Ailao Mountain in Yunnan was Methylocystaceae 20.21%.In the last three groups was Acetobacteraceae,17.83% in group A,22.87% in group B,and 19.82% in group C.There were statistically significant differences between the four groups in seven Phylums and multiple Genus,but most of them were not high abundance group.The results showed that the non-photosynthetic bacteria in the six lichen cultivars collected from Ailao Mountain,Yunnan,were statistically different from the other three groups.at Acidobacteriales and Acidobacteriaceae in the four groups with the highest proportion.The variance of the dominant taxonomy of each class is larger,Indicating that the distribution of non-photosynthetic bacteria in the samples was random.But it is common to look at 25 cases of the same type of abundance of the same class,indicating that the non-photosynthetic bacteria have species specificityRhizobium is closely related to plant nitrogen fixation,while the first class classification level,the Rhizosphere is the most dominant group of non-photosynthetic symbiotic bacteria in lichens have a fixed nitrogen role.And the presence of Actinobacteria was detected in all 25 specimens,suggesting that non-photosynthetic bacteria played a “defender” role in lichens.Based on the UniFrac distance matrix analysis,we found that seven samples of non-photosynthetic lichens' bacteria in Yunnan Ailao Mountain,which were significantly different from the other three sites at altitude,were clustered together,while the remaining 18 samples were scattered.The results showed that the factors of altitude had an effect on the non-photosynthetic bacteria community.