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

Abstract

Plant endophytic fungus is an important biological resource and has 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.

Keywords

• endophytic fungi
• analysis of its sequence
• colonization rate
• isolation rate
• isolation frequency
• shannon-wiener index