云南昭通不同生长条件下独蒜兰根内可培养真菌群落结构与多样性OA

As a traditional and precious medicinal plant in China,the orchid Pleione bulbocodioides requires symbiosis with fungi to complete its life cycle under natural conditions.Therefore,the isolation and identification of symbiotic fungi are crucial for solving its resource regeneration using symbiotic technology in the future.In this study,wild,semi-wild(understory simulated wild)and artificially cultivated P.bulbocodioides plants in Zhaotong,Yunnan Province were used as research objects to compare and analyze the composition and diversity of culturable endophytic fungal communities in their roots under different growth conditions.Three isolation methods,tissue separation,single hyphal mass,and dilution grinding,were adopted.Total 619 fungal strains were obtained.These strains were identified through morphological observation and internal transcribed spacer(ITS)rDNA sequence analysis,belonging to 4 phyla,9 classes,20 orders,30 families,and 40 genera,with an overall isolation rate of 6.76%.There were significant differences in the endophytic fungal community structure in the roots of P.bulbocodioides under different growth conditions.The semi-wild samples in the understory had the highest fungal diversity(Hʹ=2.726,D=0.905 5)and the most balanced community structure(J=0.827 1),with Irpex as the dominant genus(IF=21.23%);the artificially cultivated samples in the cultivation base concentrated dominant strains,mainly belonging to Dactylonectria(IF=54.18%);the wild samples yielded the least culturable fungal resources,with only 4 genera isolated,dominated by Neopyrenochaeta(IF=60.00%).The results indicated that P.bulbocodioides under the understory semi-wild cultivation mode had a more stable and diverse endophytic symbiotic microbial system.This discovery is beneficial for screening useful symbiotic fungi and optimizing artificial cultivation modes of P.bulbocodioides.