Identification of Bacillus species causing bacterial leaf spot of peach in China

Peach (Prunus persica L.) is an economically important fruit and is cultivated widely in the world. Bacterial leaf spot (BLS) is a major disease limiting the yield of peach in most peach‐producing areas worldwide. To identify the pathogen causing bacterial leaf spot, evaluate its pathogenicity, and explore its host range, the diseased leaves were collected. Phylogenetic analysis of the partial 16S rRNA genes showed that the five isolates belong to the Bacillus cereus species complex. Three of the five isolates were identified as B. cereus, with the remaining isolates being B. thuringiensis and B. pacificus, based on multilocus sequence analysis (16S rDNA, adk, ccpA, ftsA, glpT, pyrE, recF, and sucC) and biochemical characteristics. All five isolates were pathogenic on Prunus persica as well as on Cerasus pseudocerasus, but none of the isolates was pathogenic on C. humilis, plum (Prunus salicina), or Armeniaca vulgaris. To our knowledge, this is the first report on the occurrence of B. cereus species complex as causal agents of BLS of peach, which will benefit the development of future control measures.