云南三个地区马铃薯内生真菌多样性研究

Diversity of endophytic fungi isolated from Solanum tuberosum in three regions of Yunnan

关键词:  内生真菌, ITS序列分析, 定殖率, 分离率, 分离频率, 香农多样性指数

Key words:  endophytic fungi, analysis of ITS sequence, colonization rate, isolation rate, isolation frequency, Shannon-Wiener index

摘要:

为研究云南马铃薯(Solanum tuberosum)内生真菌的多样性,该文以采自云南省德宏芒市、大理喜洲和临沧双江3个地区的马铃薯植株为研究对象,采用组织块分离法、尖端菌丝挑取法对马铃薯根、茎及块茎中的内生真菌进行分离纯化,并采用形态学鉴定方法和ITS序列分析法对分离得到的内生真菌进行鉴定,对内生真菌的定殖率、分离率及多样性指数进行计算和分析。结果表明:(1)共分离得到内生真菌98株,其中从德宏芒市的样品中获得40株,从大理喜洲的样品中获得27株,从临沧双江的样品中获得31株。(2)经鉴定,分离得到的马铃薯内生真菌共涵盖10目10科13属,大多为子囊菌门和担子菌门,优势菌为镰刀菌属(Fusarium)和青霉属(Penicillium),褶皱裸孢壳(Emericella rugulosa)、接骨木镰刀菌(Fusarium sambucinum)、毛韧革菌(Stereum hirsutum)、Psathyrella sulcatotuberculosa和Epicoccum catenisporum 5种真菌均为首次从马铃薯植株中分离得到。(3)马铃薯块茎内生真菌的定殖率最高,根部内生真菌定殖率最低; 内生真菌的分离率以马铃薯根部为最高,而茎部最低; 不同组织中内生真菌的多样性指数趋势均为根>块茎>茎。从综合来看,云南马铃薯植株中的内生真菌具有较高的多样性,不同地区的马铃薯样品中内生真菌优势菌不同,马铃薯根部具有最丰富的内生真菌种群和最高的分离率,是最适合进行内生真菌分离的材料。该研究结果为后期探究马铃薯内生真菌对病原菌的拮抗作用奠定了基础,也为马铃薯内生真菌多样性研究提供了参考数据。

Abstract:

Plant endophytic fungus is an important biological resource and have shown significant applications in medicine and in the biological control of agricultural pests and diseases. In order to study the diversity of endophytic fungi of potato(Solanum tuberosum), samples from three regions of Yunnan Province, namely, Dehong Mangshi, Dali Xizhou, and Lincang Shuangjiang. The endophytic fungi in potato roots, stems and tubers were isolated and cultured using the method of tissue block isolation. Well-grown colonies were purified using the method of tip mycelium selection. The endophytic fungi were identified by morphological methods and ITS sequence analysis. Then, the colonization rate, isolation rate and diversity index of the endophytic fungi were calculated and analyzed. The results were as follows:(1)A total of 98 endophytic fungi were isolated, including 40 strains samples from Dehong Mangshi, 27 strains from Dali Xizhou and 31 strains from Lincang Shuangjiang.(2)The endophytic fungi isolated from potato were identified to include 10 orders, 10 families and 13 genera, mostly of the Ascomycota and Basidiomycota, with Fusarium and Penicillium as the dominant fungi. Five species of fungi, Emericella rugulosa, Fusarium sambucinum, Stereum hirsutum, Psathyrella sulcatotuberculosa and Epicoccum catenisporum were first reported to be isolated from potato plants.(3)Potato tuber had the highest colonization rate of endophytic fungi and root had the lowest; while the isolation rate of endophytic fungi was highest in potato root and lowest in stem; trend of diversity index of endophytic fungi in different tissues were H'_root > H'_tuber > H'_stem. In conclusion, the endophytic fungi in Yunnan potato plants are highly diverse, with different endophytic fungal dominants in potato samples among the three localities, potato root has the richest endophytic fungal populations and the highest isolation rate, and are therefore the most suitable material for endophytic fungal isolation. The above results provide a reference for later investigation of the antagonistic effect of endophytic fungi on pathogens in potato.