An overview of the diversity of pathogens causing bacterial spot on tomato and pepper in Bulgaria

Nevena Bogatzevska, Taca Vancheva-Ebben, Katya Vasileva, Yoana Kizheva and Penka Moncheva

Abstract: Bacterial spot (BS) is a destructive disease affecting tomato and pepper plants. A wide diversity among the pathogens causing this disease makes them a serious threat for the tomato and pepper production worldwide, including Bulgaria, where the disease has become a major problem. To date in Bulgaria three species have been identified that infect tomato (X. vesicatoria, X. euvesicatoria and X. gardneri), and two that infect pepper (X. vesicatoria and X. euvesicatoria). Despite the research and published data, there is no general information about the BS agents on tomato and pepper in Bulgaria in respect to pathotypes, races, and the dynamics of pathogenic populations during the years. In this study we analyzed and summarized for the first time the data on the species, pathotype and race structure of the pathogenic population during the period 1999-2016. BS on tomato is caused by three species (X. vesicatoria, X. gardneri and X. euvesicatoria), and on pepper – by two species (X. euvesicatoria and X. vesicatoria). X. vesicatoria was detected and identified at the beginning of this period. This species is a dominant pathogen on tomato, whereas on pepper dominates the X.euvesicatoria species. We found a significant race diversity especially for the PT strains of X. vesicatoria and PT and P strains of X. euvesicatoria. The occurrence of new races over the past years has been registered, replacing those established at the beginning of the observed period. This indicates that the pathogenic population responsible for BS on tomato and pepper is dynamic and needs to be regularly monitored and studied, which is important to control the disease.

Keywords: bacterial spot agents; diversity; pathotype; pepper; race; tomato

Date published: 2021-02-25