Isolation, Identification and Biological Characteristics of Pathogenic Bacteria of Acer rubrum Canker Disease

Purpose To identify the pathogen responsible for canker disease in Acer rubrum in Aziying, Kunming City, Yunnan Province, and to investigate its biological characteristics.

Methods A total of 10 typical samples of diseased A. rubrum were collected locally. Suspected pathogens were isolated and purified by plant tissue isolation and single-spore purification methods. The causative pathogen was confirmed according to Koch’s postulates. Morphological characteristics and multi-gene phylogenetic analysis (ITS-TUB2-EF1-α) were employed to determine the taxonomic identity of the pathogen. The biological characteristics of the representative strain were further analyzed by colony growth assays.

Results A total of nine fungal isolates with consistent morphological features were obtained. The representative strain, FJ12, was identified as Botryosphaeria dothidea. Under experimental conditions, the optimal growth temperature for this strain ranged from 20 ℃ to 30 ℃, with glucose as the most suitable carbon source and peptone as the most suitable nitrogen source.

Conclusion The pathogen causing A. rubrum canker disease in Aziying, Kunming City, Yunnan Province, is identified as B. dothidea. This is the first report of B. dothidea causing A. rubrum canker disease in China. The preliminary investigation of its biological characteristics provides a theoretical basis for disease prevention and control.