[Community structure and diversity of entophytic bacteria in Tricholoma matsutake in Sichuan Province, Southwest China].

In order to understand the diversity and community structure of endophytic bacteria in Tricholoma matsutake, 14 Tricholoma matsutake samples were collected from 7 main production counties of Xiaojin, Yajiang, Muli, Yanyuan, Yanbian, Huidong and Mianning. The entophytic bacterial community structure and diversity were investigated by PCR denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that the diversity and community structure of endophytic bacteria in T. matsutake varied significantly, while those from the environments alike had high similarity. In addition, each T. matsutake sample contained more than 15 species of endophytes, with that from Yanyuan having the highest endophytes diversity index and abundance, while those from Xiaojin were the lowest. Phylogenetic tree showed that endophytic bacterial species in T. matsutake were abundant. Dominant bacterial population in T. matsutake collected from different places varied, and Pseudomonas, Ewingella and Bacillus were distributed in all samples and retained a certain advantage. Alcaligenes and Sphingobacterium distributed in most samples, while Duganella and Lysinibacillus only in certain ones. This study demonstrated that the endophytic bacteria in T. matsutake were abundant and diversified, which could be in favor of searching the dominant bacteria promoting the growth of T. matsutake.

[Endophytic bacterial diversity in Codonopsis pilosula, Ephedra sinica, and Lamiophlomis rotate: a study with LH-PCR].

To investigate the endophytic bacterial diversity in the three medicinal plant species Codonopsis pilosula, Ephedra sinica, and Lamiophlomis rotata in Ganzi of Sichuan, Southwest China, the total DNA of the three species were extracted by stringent surface sterilization, and studied with length heterogeneity-PCR (LH-PCR) method. For the same plant species, their root-, stem-, and leaf LH-PCR profiles were in a high level of similarity, with little differences in band richness. However, there existed great differences in the LH-PCR profiles among different plant species. C. pilosula had the biggest band richness, followed by E. sinica, and L. rotata. In the three plant species, the endophytic bacteria with an approximately 474 bp DNA length were dominant. The endophytic bacterial diversity of the plants was negatively correlated with rhizosphere soil available phosphorus content, but positively correlated with rhizosphere soil pH. Elevation and rhizosphere soil total nitrogen content were the important environmental factors affecting the distribution of enophytic bacteria in these plant species. The information of population diversity obtained from LH-PCR could more intuitively reflect the differences of bacterial diversity among different plant species, and thus, LH-PCR would be available to be used for analyzing the endophytic bacterial diversity in medicinal plants, providing information and guidance for the further isolation of microbial resources.

[Effects of Armillariella tabescens polysaccharide IPS-B2 on activity of mouse peritoneal macrophages and transcription of related gene].

OBJECTIVE: To observe the effect of IPS-B2 on mouse peritoneal macrophages and the transcription of IL-1beta, IL-6, TNF-alpha and iNOS. METHOD: ELISA method and Griess method were used to detect the effect of mouse peritoneal macrophages produce cytokines IL-1beta, IL-6, TNF-alpha and cytotoxic effectors NO. The transcription of IL-1beta, IL-6, TNF-alpha and iNOS was detected by real-time RT-PCR method. RESULT: IPS-B2 could not promote mouse peritoneal macrophage production, but it could significantly improve the IL-1beta, IL-6, TNF-alpha content in mouse peritoneal macrophages culture supernatant, and increase the gene expression of IL-1beta, IL-6, TNF-alpha and iNOS. CONCLUSION: IPS-B2 can enhance the ability of peritoneal macrophages to excrete bioactive substances and promote the transcription of bioactive substances to antitumor.

[AFLP analysis for genetic diversity of Ganoderma].

OBJECTIVE: To investigate the genetic diversity of Ganoderma cultivars provided for the genuineness study, germ-plasm resource identification, genetic relationship study, breeding, introduction and cultivante of Ganoderma strains. METHOD: With the software of NTSYSpc 2. 1, 24 materials, of G. lucidum and G. sinense, were studied using AFLP to construct the dendrogram. RESULT: There were 177 polymorphic bands with 14 primer combinations. And all materials could be identified with AFLP. CONCLUSION: There actually existed much genetic diversity at the molecular level among the germplasm resources of Ganoderma strains, and all the strains were clustered into G. lucidum group and G. sinense group at the similarity coefficient 0. 676.