Screening of an Antagonistic Endophytic Actinomycete from Rhodiola rosea and its Resistance to Fungicide

Purpose In order to explore new potential biocontrol member for controlling plant disease, the endophytic actinomycetes from Rhodiola rosea with fungistasis were researched.Method In this study endophytic actinomycetes from the joint position of root and stem of Rhodiola rosea were isolated and screened the antagonistic activity to plant pathogens using confrontation culture method and mycelial growth rate method. Then,the 16S rRNA gene sequence and antifungal spectrum of the strain with the best fungistasis were also determined. And to assess the possibility the strain used with fungicide, the resistance of the strain with the best fungistasis to commonly-used fungicides were tested.Results The result showed that 7 isolates possessed the antagonistic activity among 19 endophytic actinomycetes, and the fungistasis of Hj3 (Streptomyces variabilis) was the strongest and could inhibit all plant pathogens provided by the experiment. Also, Hj3 could grow well above the highly dose of boscalid, polyoxin, nalidixic acid, and ampicillin, respectively.Conclusion There is certain advantage for Hj3 to control usual plant disease.