Molecular characterization of Aureobasidium spp. strains isolated during the cold season. A preliminary efficacy evaluation as novel potential biocontrol agents against postharvest pathogens

Abstract

Several Aureobasidium spp. strains isolated from wild environments during winter 2022 were characterized by sequence analysis of the internal transcribed spacer (ITS), the translation elongation factor EF-1α gene (EF1), and part of the elongase gene (ELO). The variability in the EF1 and ELO loci are higher than in the ITS. All strains but one (UC14), were identified as A. pullulans. To assess the effectiveness of the characterized strains as biocontrol agents (BCAs) of diseases occurring during postharvest storage, a selection of the strains was evaluated by in vitro and in vivo assays. On average, the reduction of Monilinia spp. colony growth was more marked for non-volatile metabolites than for volatile (VOCs). Strain UC14 provided the strongest mycelial growth reduction of Monilinia fructicola by VOCs (66%). According to the in vivo results, all strains were effective in controlling brown rot during cold storage and remarkably in restricting the growth of Monilinia polystroma. In particular, VB23 was the most effective in controlling brown rot incidence, by 80%, 60%, 100%, and severity, by 79.5%, 72.7% and 100%, for Monilinia laxa, M. fructicola, and M. polystroma, respectively.

Exploring Wild and Local Fruits as Sources of Promising Biocontrol Agents against Alternaria spp. in Apples

“…pullulans is a well-known and studied yeast species for its biocontrol potential against several postharvest diseases such as the gray mold caused by B. cinerea [31], brown rot caused by Monilinia spp. [32,33], and blue/green mold caused by Penicillium spp. [34].…”

“…Secretion of nVOCs by antagonistic yeasts has been reported as a potential mechanism of action against several pathogens, including Aspergillus flavus [16], Monilinia spp. [32], and B. cinerea [38]. It is known that the cyclic peptides secreted by BCAs inhibit fungal pathogen growth by disturbing the fundamental components of the fungal cell walls [39].…”

Juvenile Plant–Microbe Interactions Modulate the Adaptation and Response of Forest Seedlings to Rapid Climate Change

“…This yeast has been isolated from wild environments, such as deserts and tree leaves [ 142 , 143 ]. The ability of this yeast to grow in cold conditions can effectively manage seed storage in native forest seed banks, as some psychrophilic opportunistic pathogens can also affect seed viability [ 144 ]. Similarly, the genus Bacillus sp.…”

Insights into the molecular phylogeny and morphology of three novel Dothiora species, along with a worldwide checklist of Dothiora

“…Members of this order are saprobic and occasionally pathogenic to plants in terrestrial habitats and humans, including house dust (Thambugala et al, 2014;Crous et al, 2018a;Hongsanan et al, 2020). In addition, some species have been used as potential biocontrol for pest management (Zajc et al, 2019;Cignola et al, 2023). To date, 26 genera were accepted in Dothideales, while six genera were proposed in Dothideales genera incertae sedis (Wijayawardene et al, 2022).…”