Peach bacterial shot hole is a major disease limiting the yield and quality in most peach-producing areas worldwide. To clarify its etiology and support the development of targeted management strategies, diseased samples were collected from Changli County peach orchards. The pathogen was isolated, purified and verified by Koch’s postulates. Based on morphological, biochemical and multi-locus phylogenetic analyses, the causal agent was identified as Xanthomonas arboricola pv. pruni (isolate TCK-5). Biological characterization revealed that TCK-5 grew optimally in KB and NB medium at 28 °C, pH 7.0–7.5 and 0.5–1.0% NaCl, efficiently utilized glycerol and organic nitrogen source (proteose peptone, beef extract and yeast extract), with light showing no significant effect on growth. The strain TCK-5 exhibited a lethal temperature of 51 °C, indicating that heat treatment above this threshold effectively disinfects pruning tools and contaminated plant debris. Among 18 bactericides tested in vitro, biological bactericide outperformed chemical ones, with 0.3% Tetramycin AS (EC50 = 0.1051 mg/L) and 3% Zhongshengmycin SL (EC50 = 2.9252 mg/L) exhibiting the strongest inhibitory activity. This study fills a regional knowledge gap in the epidemiological distribution of the pathogen in northern China and advances current understanding of X. arboricola pv. pruni occurrence, providing a scientific basis for subsequent epidemic monitoring and integrated control of peach bacterial shot hole.
Cui et al. (Sat,) studied this question.