Identification and Biological Characteristics of Tea Bud Blight Pathogen

Objective The pathogen that causes bud blight on tea plants was identified and biologically characterized to facilitate disease control.

Method A suspected pathogen was isolated using the tissue isolation method. Taxological identification of the isolate was conducted by morphological examination, molecular analysis, and pathogenicity determination. Mycelial growth and sporulation of the isolate on potato dextrose agar (PDA), potato sucrose agar (PSA), oatmeal agar (OA), malt extract agar (MEA), corn meal agar (CM), and V8 juice agar (V8) media were observed with optimal culture conditions determined.

Result The microorganism that caused tea bud blight was identified to belong to Phyllosticta capitalensis with the phylogenetic tree clustered with other strains in the family. The pathogenicity of the isolate followed Koch's postulates that rendered disease symptoms similar to natural infection in the field. At 25 °C and pH 6, a maximum growth rate of the isolate was shown on V8 medium and the greatest sporulation on PSA.

Conclusion The pathogen responsible for the bud blight on tea bushes in this study was identified to be P. capitalensis. It propagated well on PSA at 25 °C and pH 6.