Pathogen causing Phalaenopsis soft rot disease - 16S rDNA and virulence characterisation

Abstract

The pathogen causing Phalaenopsis soft rot disease and developed detached leaf inoculation methods were identified. Based on its 16S rDNA sequences, the pathogen causing soft rot disease in Phalaenopsis was Erwinia chrysanthemi/Dickeya chrysanthemi. Both virulent and avirulent strains were revealed. The detached leaf inoculation assay for E. chrysanthemi/D. chrysanthemi resistance evaluation included wounding and inoculating the detached leaf with 108 CFU/ml of bacteria. Soft rot disease symptoms in the inoculated detached leaf were measurable at 20 h after inoculation. The detached leaf assay was applicable for evaluating Phalaenopsis germplasm and progeny resistance in Phalaenopsis breeding programs.

Keywords

• erwinia/dickeya chrysanthemi
• moth orchids
• detached leaf inoculation assay