Cork Oak Endophytic Fungi as Potential Biocontrol Agents against Biscogniauxia mediterranea and Diplodia corticola

Abstract

An increase in cork oak diseases caused by Biscogniauxia mediterranea and Diplodia corticola has been reported in the last decade. Due to the high socio-economic and ecologic importance of this plant species in the Mediterranean Basin, the search for preventive or treatment measures to control these diseases is an urgent need. Fungal endophytes were recovered from cork oak trees with different disease severity levels, using culture-dependent methods. The results showed a higher number of potential pathogens than beneficial fungi such as cork oak endophytes, even in healthy plants. The antagonist potential of a selection of eight cork oak fungal endophytes was tested against B. mediterranea and D. corticola by dual-plate assays. The tested endophytes were more efficient in inhibiting D. corticola than B. mediterranea growth, but Simplicillium aogashimaense, Fimetariella rabenhorstii, Chaetomium sp. and Alternaria alternata revealed a high potential to inhibit the growth of both. Simplicillium aogashimaense caused macroscopic and microscopic mycelial/hyphal deformations and presented promising results in controlling both phytopathogens’ growth in vitro. The evaluation of the antagonistic potential of non-volatile and volatile compounds also revealed that A. alternata compounds could be further explored for inhibiting both pathogens. These findings provide valuable knowledge that can be further explored in in vivo assays to find a suitable biocontrol agent for these cork oak diseases.

Antimicrobial properties of marine fungi from sponges and brown algae of Mauritius

“…B1b0856P152CC396 (KP306931.1), which is closely related to isolate F28, was recovered from a sponge from the Caribbean and the Pacific of Panama (Bolaños et al 2015 ). This indicates that this genus can be sponge-associated although it is known for being endophytes and pathogens in plants (Costa et al 2020 ). Additionally, Biscogniauxia sp.…”

Fungi as potential factors limiting natural regeneration of pedunculate oak (Quercus robur) in mixed‐species forest stands in Poland

“…Our exhaustive characterization revealed a high fungal richness, with 111 species from 24 orders of Ascomycota, Basidiomycota, and where the fungus has been reported from Quercus alba (Sogonov et al, 2008;Walker et al, 2010), although this fungus was recently isolated from multiple oak species in Italy (Pinna et al, 2019) and from cork oak in Portugal (Costa et al, 2020). In this study, G. paraclavulata caused dieback of inoculated oak seedlings but lesions generated on seedling stems were small.…”

“…G . paraclavulata is primarily known from the USA, where the fungus has been reported from Quercus alba (Sogonov et al, 2008; Walker et al, 2010), although this fungus was recently isolated from multiple oak species in Italy (Pinna et al, 2019) and from cork oak in Portugal (Costa et al, 2020). In this study, G .…”

Impact of Charcoal Canker on Oak Trees at a Site of Community Importance: Case Study of the Relict Castelfidardo Forest (SIC Area IT520008, Castelfidardo, AN, Italy)

“…Therefore, among the possible control strategies, it would be appropriate to: (i) eliminate all dead trees with sporulating cankers; (ii) carry out thinning, to reduce the tree densities, particularly for plots #3, #4, and #5; and (iii) explore the possibility of using antagonistic microorganisms (e.g., Trichoderma spp.) for repression of this stress-mediated disease [67].…”