Genetic heterogeneity among Xanthomonas campestris pv. campestris isolates originated from oilseed rape determined with different rep-PCR techniques

Abstract

Background: Oilseed rape (Brassica napus) is an oil-producing crop, significant for vegetable oil and biodiesel production. The phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc) causing bacterial leaf blight was recorded for a first time in 2010 on self-growing winter oilseed rape in Serbia. Ever since, it continued appearing on cultivated crops too. Objectives: The aim of this research was to reveal genetic heterogeneity among 25 Xcc isolates, originated from different cultivars of winter oilseed rape obtained in nine-year period (2010-2018) from different localities in Vojvodina region (Serbia) using repetitive sequence-based PCR (rep-PCR) fingerprinting. Methods: Genomic DNA was extracted using CTAB method. Specific primer pair XCF/XCR, amplifying a DNA fragment of hrpF gene from X. campestris was used for rapid preliminary identification of all tested isolates. Rep-PCR using BOX, ERIC and REP-PCR primers was used to detect presence of genetic heterogeneity among Xcc isolates. Results: All 25 tested isolates were preliminary identified as Xcc based on a positive PCR reaction after amplification of 525 bp region using XCF/XCR primers. BOX and ERIC-PCR generated seventeen different DNA fingerprinting profiles, unlike REP-PCR where only nine different profiles were detected. These results show presence of genetic polymorphism among Xcc isolates from winter oilseed rape, which could indicate either their affiliation to some of the identified Xcc races, or formation of a new Xcc ecotype.