Study On The Distirbution Of Endophytic Bacteria In Dendrobium Officinale

The growth of Dendrobium officinal is closely related to endophytes. At present, there are many studies show that endophytic fungi have promoting effect on Dendrobium officinal, however, the diversity and function of endophytic bacteria are seldom reported. This paper studies the distribution of endophytic bacteria in Dendrobium officinal root, stem, leaf and diversity of Dendrobium officinal endophytic bacteria from different planting base and wild resources, which may be helpful for the study of interaction between Dendrobium officinal and endophytic bacteria.Firstly, the distribution of endophytic bacteria in root, stem, leaf of planting Dendrobium officinal in Wenzhou was investigated using the method of PCR-DGGE combined with traditional culture-dependent. Using the two methods,22strains belonging to13genus were identified in root, and Bacilluswas the major genus. Totally22strains belonging to11genus were identified in stem, and Burkholderia was the main genus. Altogether17strains belonged to8genus were identified in leaf, and Pseudaminobacter was the main genus. Obviously, the diversity of endophytic bacteria in root is richer than stem and leaf. Endophytic bacteria of leaf are less and have no regularity. Therefore, endophytic bacteria of Dendrobium officinal were mainly distributed in root and stem.The distribution and dominant species of Dendrobium officinal endophytic bacteria were investigated in planting samples from Wenzhou, Qingyuan, Xiaoshan and Fenghua using culture-dependent and PCR-DGGE methods. It indicated that the diversity of Dendrobium officinal endophytic bacteria in Xiaoshan was much more abundant, followed by Fenghua. Bacillus is the dominant population of Dendrobium officinal using culture-dependent methods, which mainly distributed in root. Burkholderia is the dominant population of Dendrobium officinal using PCR-DGGE methods, which mainly distributed in stem. To Compare the two methods,44strains belonging to19genus were identified in Wenzhou, and the main genus were Brevundimonas and Pseudaminobacter. Altogether42strains belonging to16genus were identified in Qingyuan, and the main genus were Pseudomonas, alpha proteobacterium and Sphingomonas. Totally40strains belonging to22genus were identified in Xiaoshan, and the mainly genus was Rhodanbacter. Totally50strains belonging to23genus were identified in Fenghua, and the major genus were Pseudomonas, Microbacterium and Rhizobium. The distribution of endophytic bacteria except for the Bacillus and Burkholderia showed the host difference from four planting bases, which might due to the influence of geography climate, living environment, planting pattern and sampling date.The bacterial distribution of wild Dendrobium officinal was studied in plants living in natual environment using culture-dependent method. The results indicated that17strains belonging to13genus were identified in samples from Wenzhou, and the main genus was Pantoea. Totally11strains belonging to4genus were identified in Qingyuan, and the main genus was Bacillus. Obviously, the diversity and abundance of wild Dendrobium officinal endophytic bacteria in Wenzhou was higher than that in Qingyuan sample. Compared with planting samples, the wild resources possessed some special genus, such as Stenotrophomonas, Pantoea, Herbaspirillum, Microbacterium and Serratia. These strains have varied functions on, such as nitrogen fixation, which may have significant effect on the growth of wild Dendrobium officinal.In summary, this paper preliminarily analyzed the distribution of Dendrobium officinal endophytic bacteria in different tissues. It indicated that the distribution of endophytic bacteria was different between different planting samples, between different wild samples, as well as between planting and wild samples, which might provide the possibility to study further the function of endophytic bacteria and the interaction between endophytic bacteria and the host.