Prevalence of Berkeleyomyces basicola infections in black rot-affected carrot determined using the MCM7 gene region

Thielaviopsis and related taxa are responsible for losses in several agricultural crops. In carrot these pathogens can cause black rot, mainly after harvesting. Molecular studies using species-specific DNA sequences are the principal tools for accurate identification of these pathogens. The objective of this work was to investigate which taxa are associated with black rot in carrot in Brazil using gene markers and Bayesian phylogenetic analysis. Eighteen isolates were obtained from carrots with symptoms of black rot. Through morphological characteristics all isolates were classified as Thielaviopsis-like. Bayesian inference using only MCM7 sequences and a concatenated data set (LSU, MCM7 and 60S rRNA) allowed identification of all isolates as belonging to Berkeleyomyces basicola. All isolates induced black rot in carrot. Although our studies include a small number of isolates, the results indicate the likely predominance of B. basicola in causing black rot in carrot in Brazil, and that MCM7 sequences are enough to distinguish the Berkeleyomyces species by Bayesian inference.