The Research On The Diversity Of The Endophytic Bacteria In Three Medicinal Plants

In this study, we isolated endophytes from Codonopisis pilosula, Astragalus membranaceus, Forsythia suspcnsa in three medicinal transfer plants growing in the high altitude, strong radiation, temperature fluctuations in the Qinghai-Tibet plateau.By using conventional cultivation method, determined some physiological characteristics and functions of isolates.At the same time, we also analyzed the abundance, diversity and community structure of endophytes in three medicinal plants by means of RFLP and 16SrRNA sequence analysis, and study the relationship between environment and endophytic bacteria interaction. The major results are as follows:1. Three kinds of medicinal transfer plants in the Qinghai-Tibet Plateau are abundance in endophytic bacteria and in a wide range of types. A total of 42 endophytic bacteria isolated were obtained from Codonopisis pilosula, Astragalus membranaceus, Forsythia suspcnsa in 3 transfer medicinal plants after phenotypic analysis.Of which belongs to 9 genera,such as Micrococcus sp. ,Bacillus sp. ,Caryophanon sp.,Flavobacterium sp., Chryseobacterium sp., Sphingobacterium sp., Acinetobacter sp., Kocuria sp., Sporosarcina sp..2. The results of characteristics determination showed that endophytic bacterial in three transfer medicinal plants also displayed abundance and diversity in morphology and properties. Most of isolates(81.33%) could produce pigments with the colour of yellow, orange and pink.And gram-positive bacteria (58.33%) were isolated more frequently than gram-negative bacteria from three medicinal plants plants. Moreover most strains (58.33%) were rod shape, The rest is spherical, and the strains are different in size. These characteristics of endophytes were closely related to their origin and the growth environment of their host plants, low temperature and strong UV radiation. It also implied that microorganism, being contained in similar environment conditions, whosecharacteristics were similar, too.3. Endophytic bacteria from three transfer medicinal plants vested inβ-proteobacteria, HGC, LGC and CFB. Of which, HGC group formed the largest cluster and possessed the highest taxonomic diversity, for which were observed in each plant species ,accounting for 41.67% in all isolates. Of these, Micrococcus is the most prevalent genera. LGC and CFB were the second large groups inferior to HGC, they all account for 25% and are more dispersed distribution of species.4. To some extent, the environmental factors influence physical and chemical properties of endophytic bacteria from three kinds of medicinal plants, plants endophytic bacteria of the physical and chemical properties to some extent also reflect the climatic characteristics of the local environment.5. Endophytic bacteria from three medicinal plants have a certain degree of resistance to antibiotics, which enriched with the biological role of endophytic bacteria from transfer medicinal plants on a very large extent. Also proved that the medicinal plants of endophytic bacteria as the medicinal plant itself also has some resistance activity, such as producing antibacterial activity substances, as antimicrobial active substances and anti-HIV active substance.