Identification and Inhibitory Effect on Lasiodiplodia theobromae of Actinomycetes in Camellia sinensis Rhizosphere Soil

  Objective  Actinomycetes collected from the rhizosphere soils of old tea plants were isolated to screen for species unknown previously and their potential pathogenic inhibitory effect.

  Method  Soil specimens were gathered from the target lots at Shuixian, Fujian to isolate actinomycetes by plate culture. Phylogenetic trees based on 16S rRNA gene for the isolates were constructed and diversity index calculated in the tea plant rhizosphere soils.

  Result   (1) Eighty-one actinomycete strains were obtained that belonged to Streptomyces(54.32%), Arthrobacter (27.16%), Microbacterium (11.11%), Kitasatospora(4.94%), and Curtobacterium (2.47%). (2) In comparing with the reference strain, 20 of the 81 taxa showed less than 98.65% similarity. (3) Seven strains of the Streptomyces significantly inhibited the growth of Lasiodiplodia theobromae, of which, the one code-named WYS-24 reached the highest rate at 63.92%.

  Conclusion   Abundantly diverse actinomycetes resided in the rhizosphere of old tea plants in Wuyishan region. They were a rich resource for in-depth studies and development for biological inhibitors against plant pathogens.