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

Abstract

Carrot (Daucus carota) is an important vegetable grown around the word. In Brazil, carrots have been grown throughout the year in all geographic regions, with more than 20,000 hectares and half a million tonnes produced per year (Boiteux et al., 2017; CEPEA, 2021).Carrot cultivation is affected by several diseases that can cause quantitative and qualitative losses. Among the main diseases, black rot stands out particularly during the storage and commercialization of roots. Black rot infection in carrots is characterized by the appearance of dark necrotic lesions on the root surface. These symptoms can be observed in the field but develop mainly in the postharvest stages (Lopes & Reis, 2016;Paulin-Mahady et al., 2002).Black rot infection in carrot has been associated with species of Thielaviopsis. However, the taxonomy of the causal agent is confusing because the main taxon associated with the disease has undergone several reclassifications over time (de Beer et al., 2014;Nel et al., 2018). In the past, based on comparisons of morphological structures, the causal agent was named ambiguously as Chalara elegans or Thielaviopsis basicola (Dalbosco et al., 2004;Silva & Costa, 2013). This ambiguity is probably due to the use of morphological markers that are shared with other taxa belonging to the Ceratocystidaceae family. Paulin and Harrington (2000), using species-specific DNA sequences as phylogenetic markers, inferred that T. basicola grouped with several anamorphic species of Ceratocystis. Later, studies by the same authors suggested that Thielaviopsis should be considered the ideal genus to accommodate Chalara species. T. basicola has been proposed as the corresponding name for the aetiologic agent of black root rot (Paulin-Mahady et al., 2002).In 2014, phylogenetic analyses using DNA sequences from several genes showed that T. basicola belongs to a new phylogenetic lineage that does not group with any known genus in Ceratocystidaceae (de Beer et al., 2014). These multigenic analyses provided evidence that "T. basicola" is represented by two distinct phylogenetic lineages, reclassified as a new genus, named Berkeleyomyces, a new combination

Comparative analysis of two neighboring conducive and suppressive soils towards plant parasitism caused by Phelipanche ramosa L. Pomel on Brassica napus L.

“…Thielaviopsis basicola) of Ceratocystidaceae family, known as serious plant pathogens responsible for black root rot in several crops. [119,120]. Upon tissue penetration and colonization, the species B. basicola enters a necrotrophic phase during which it lyses and consumes plant root cells [121].…”

Berkeleyomyces rouxiae is a causal agent of root rot complex on faba bean (Vicia faba L.)

“…Recently, Nel et al. (2018) performed a phylogenetic analysis using DNA sequence data of six different gene regions and showed that the isolates of T. basicola represent two distinct fungal species in the newly described genus Berkeleyomyces , B. basicola and B. rouxiae , which are morphologically indistinguishable but can be distinguished by molecular characterization ( Crous et al., 2021 ; Cavalcante et al., 2022 ).…”