四川阿坝不同生境绿绒蒿内生放线菌多样性

Diversity of endophytic actinomycetes from Entire meconopsis sampled in Aba, Sichuan

摘要:

【背景】目前国内外对绿绒蒿内生放线菌的研究较为鲜见，利用可培养和免培养的方法可以丰富绿绒蒿内生放线菌资源。【目的】药用植物绿绒蒿生长于高海拔地区，而四川阿坝州生态环境适合绿绒蒿的生长，本研究旨在探究绿绒蒿内生放线菌的多样性及群落结构。【方法】从阿坝州6个不同地理位置采集的药用植物绿绒蒿，经严格的表面消毒后，用可培养和PCR-DGGE技术相结合的方法对其内生放线菌进行分析。【结果】可培养方法分析表明不同器官放线菌数量为根>叶>茎>花；16S rDNA限制性内切酶片段长度多态性(RFLP)分析将供试菌株分为7个遗传群，系统发育分析表明，绿绒蒿内生放线菌可分为3簇遗传群落，链霉菌属(Streptomyces)为优势菌群，占总数的50%，还包括北里孢菌属(Kitasatospora)和厄氏菌属(Oerskovia)，其中茎分离的放线菌多样性最好。不同地理位置的绿绒蒿经过PCR-DGGE技术分析表明，采样点松潘尕力台的根、茎、叶多样性指数最好，红原安曲乡的花多样性指数最好，而同一地理位置绿绒蒿内部组织之间总体来看茎和花的多样性指数最好，通过测序条带系统发育发现绿绒蒿内生放线菌可分为8簇遗传群落，红球菌属(Rhodococcus)为优势菌群，占总数的70%，还包括棒杆菌属(Corynebacterium)、诺卡氏菌属(Nocardia)、微球菌属(Micrococcus)、栖霉菌属(Mycetocola)、微杆菌属(Microbacterium)、假诺卡氏菌属(Pseudonocardia)和链霉菌属(Streptomyces)。【结论】绿绒蒿根、茎、叶、花组织中具有丰富的多样性，能够为以后活性物质和药用功效的研究奠定基础。

Abstract:

[Background] At present, the study on the endophytic actinobactreia from Entire meconopsis is relatively rare, the resource of endophytic actinobactreia from Entire meconopsis can be enriched with available culture and non-cultured methods. [Objective] To explore the diversity and community structure of endophytic actinobactreia from Entire meconopsis, a medicinal plant growing at high elevation, samples were collected from a special ecological environment in Aba, Sichuan Province. [Methods] Six different geographical positions were determined to sample and available culture method as well as PCR-DGGE technology was applied to investigate the diversity of endophytic actinobactreia from Entire meconopsis after a thorough surface disinfection. [Results] Based on culture method, the largest amount of isolates from different plant tissues was found in the root, followed in the leaf, stem and flower, respectively. The strains were grouped into 7 genotypes through 16S rDNA-RFLP Restriction fragment length polymorphism analysis, while representative strains were divided into 3 clusters in phylogenic analysis. Streptomyces was the dominant genus accounting for 50%, followed by Kitasatospora and Oerskovia and the greatest abundance of isolates was found in stem. The results of PCR-DGGE showed that the highest diversity index of endophytic actinobactreia was from root, stem and leaf that sampled in Galitai, Songpan and that from flower sampled in Anquxiang, Hongyuan. However, the largest diversity index in the same geographical position was from stem and flower. Additionally, the sequences in phylogenic analysis were classified into 8 genotypes including Rhodococcus, Corynebacterium, Nocardia, Micrococcus, Mycetocola, Microbacterium, Pseudonocardia and Streptomyces, among which Rhodococcus was predominant representing 70%. In general, it was a more effective way of combining available culture with uncultured methods to investigate the diversity of endophytic actinomycetes from Entire meconopsis. [Conclusion] The study revealed a rich diversity from different tissues in Entire meconopsis and laid foundation for further researches in active substances and medicine efficacy.