GENETIC DIVERSITY OF SERBIAN ISOLATES OF XANTHOMONAS CAMPESTRIS PV. CAMPESTRIS ORIGINATED FROM WINTER OILSEED RAPE

Abstract

Oilseed rape (Brassica napus L.) is a hybrid species within Brassicaceae family, significant for its oil-rich seed, mainly used for vegetable oil and biodiesel production, but also for consumption as livestock feed. Yield of oilseed rape and other cruciferous crops can be reduced due to different plant pathogenic bacteria, fungi and pests. One of the most significant bacteria affecting crucifers is Xanthomonas campestris pv. campestris (Xcc) causing black rot disease. Xcc isolates from diseased winter oilseed rape plants showing bacterial blight symptom on leaves were collected in nine-year period (2010-2018), from different localities in Serbia, with the aim to examine their genetic features, through sequencing of housekeeping genes. DNA of the obtained isolates was therefore amplified with six primers (dnaK, fyuA, gapA, gyrB, lepA, rpoD) and sent for sequencing. The obtained sequences were checked for homology with strains available in NCBI database. Multilocus sequence analysis (MLSA) was then performed to determine relatedness among the tested isolates. Based on six genes, tested isolates were identified as Xcc using NCBI BLAST, showing 99-100% homology with the available data. Winter oilseed rape Xcc isolates were divided into five groups on Neighbour-joining tree, revealing intrapathovar diversity within isolates from this host. These results could be connected with pathogen adaptation to winter oilseed rape as a new host, providing completely distinct ecological niche from B. oleracea vegetable crops (broccoli, cabbage, cauliflower, etc.) which are common hosts for this bacteria. This observation on Serbian Xcc isolates gives a significant input on genetic variation and constitutes a highly informative sample of X. campestris diversity.