Evaluation of biocontrol effect of apple endophytic fungi on Venturia inaequalis
Paper ID : 1950-24IPPC (R3)
Authors
University of Tehran
Abstract
Endophytic fungi are microorganisms that are in the plant tissue during certain periods of their life cycle, without causing damage to the plants. They play an important role in balancing ecosystems and benefiting the host such as increasing plant growth. These fungi affect plant resistance to environmental stresses, pathogens and pests and thus can be used as biocontrol agents. In this study, the inhibitory effect of 257 endophytic fungal isolates (34 fungal genera) isolated from endemic and wild apple cultivars in the north of Iran was evaluated against Venturia inaequalis in vitro. For initial evaluation, the effect of secondary metabolites of these fungi on pathogen was tested. Among them, isolates belong to the genera Alternaria, Aspergillus, Colletotrichum, Neoscytalidium, Nigrospora, Paecilomyces, Pestalotiopsis, Penicillium and Talaromyces did not show any antagonistic effect. Among other isolates, the secondary metabolites of isolates Acremonium sclerotigenum GO13S1, Coniochaeta endophytica 55S2 and Fusarium lateritium 61S2 completely inhibited the mycelia growth of V. inaequalis. Secondary metabolites of isolates Chaetomium globosum 2S1 and 39S6, Hydeomyces desertipleosporoides GO8S2, Nemania serpens GO7L1 and Gibellulopsis nigrescens 39S5 also inhibited mycelia growth of pathogen more than 50%. Selected isolates were also evaluated based on the production of volatile compounds. Among the isolates, the volatile compounds produced by the isolates Auerobasidium microstictum 7F2, Chaetomium globosum 2S1, Ch. globosum 3L2, Coprinopsis atramentaria 52L2, Fusarium fujikuroi 37F6, Fusarium acuminatum GO2L1, Fusarium incarnatum 25S3, completely inhibited the mycelia growth of V. inaequalis. Volatile compounds of Annulohypoxylon stygium 54L1 and Hypoxylon fragiforme GO2L3 isolates showed the lowest inhibition of pathogen growth by 12.4% and 9.6%, respectively. Volatile compounds of all other isolates, except two isolates Aposphaeria corallinolutea 17S2 and Discostroma corticola 22S4, showed more than 70% inhibition of pathogen mycelia growth. The biocontrol potential of selected isolates against apple scab on apple seedlings is being evaluated in greenhouse conditions.
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