川楝内生放线菌多样性及群落结构研究
Diversity and community structure of endophytic actinobacteria of Melia toosendan

【目的】为深入挖掘川楝药材中的微生物资源，研究分析了川渝地区川楝内生放线菌的多样性和群落结构。【方法】运用PCR-DGGE技术对重庆万州、四川资阳、四川遂宁三个地区采集的川楝样品进行分析。【结果】DGGE图谱显示不同地区相同部位的样品以及相同地区的不同部位之间川楝内生放线菌都存在多样性差异，这种差异来自于地域环境和自身代谢水平的不同。不同部位总体上呈现树皮的多样性最丰富，而果实的多样性最差。对DGGE条带进行回收测序，共获得24条序列，归于11个属，链霉菌属(Streptomyces)为优势菌属占25%，其余的川楝内生放线菌归于为芽球菌属（Blastococcus）、气微菌属（Aeromicrobium）、中村氏菌属（Nakamurella）、分枝杆菌属（Mycobacterium）、棒杆菌属（Corynebacterium）、红球菌属（Rhodococcus）、冷杆菌属（Cryobacterium）、微杆菌属（Microbacterium）、诺卡氏菌属（Nocardioides）、利夫森氏菌属（Leifsonia）等稀有放线菌属，占总数的75%。【结论】分布于不同地域的川楝各组织内生放线菌多样性及群落结构存在差异，蕴藏着丰富的放线菌资源。
[Objective] The diversity and community structure of endophytic actinobacteria of Melia Toosendan collected from Sichuan and Chongqing were studied for exploring the microbial resources from Chinese medicine Melia Toosendan. [Method] Denaturing gradient gel electrophoresis (DGGE) was employed to analyze endophytic actinobacteria diversity and community structure of Melia Toosendan collected from Wanzhou (Chongqing), Ziyang and Suining, respectively. [Result] The result of DGGE showed the diversity of endophytic actinobacteria that obtained from whether different tissues of Melia Toosendan in one plant or the same tissues collected from different sampling sites were existed different, the main reason was environmental deviation or metabolic differences among plants. The richest diversity of endophytic actinobacteria of Melia Toosendan was observed in bark and the fruit was fewest. The recovery of DGGE strip series showed the 16S rRNA gene sequence similarity between the 24 stronger bands and the typical strains published in Genbank was 91% to 100%，and those sequences belonged to eleven genera, Streptomyces was dominant genera accounting for 25% of all sequences, the remainder belonging to genera Blastococcus, Aeromicrobium, Nakamurella, Mycobacterium, Corynebacterium, Rhodococcus, Cryobacterium, Microbacterium, Nocardioides, Leifsonia, which account for 75%. [Conclusion] This result revealed the endophytic actinobacteria community structure and diversity were different and abundant in different samples