Isolation and Identification of Antagonistic Endophytic Actinomycetes Against Root Rot Disease in Ligusticum chuanxiong

Objective: To get an understanding of the microflora of endophytic actinomycetes in Ligusticum chuanxiong,and to obtain the resource of antagonistic strains against Ligusticum chuanxiong root rot disease. Methods: Actinomycetes in stem nodes and rhizomes of Ligusticum chuanxiong were isolated and purified by a series of means,namely tissue block method, homogenate technique and plat streaking method. Further, dual culture and inhibition zone method were employed to test the antagonistic activity of these strains. To identify strains with potential precisely,both microscopic observation and DNA sequencing were conducted. Results: 83 strains of Ligusticum chuanxiong endophytic actinomycetes were identified, which consisted of 13 species groups. Among all of them,species identified as Streptomyces scopuliridis( KF600747. 1), Streptomyces griseorubiginosus( AB706352. 1) and Streptomyces agglomeratus( LC055413. 1) showed antagonistic activities against four kinds of pathogenic fungi of Ligusticum chuanxiong root rot disease. Conclusion: Actinomycetes which belong to Griseorubroviolaceus groups of streptomyce are potential biocontrol microbes to Ligusticum chuanxiong root rot,showing importance to the production of Chuanxiong Rhizoma.