IN VITRO ANTAGONIC ACTIVITY OF A Fusarium solani ENDOHYTIC STRAIN TOWARD PHYTOPATHOGENIC FUNGI

CECATI FRANCISCO M.; DIMARI GINA; RETA, GUILLERMO F.; GONZALEZ MELISA; MAGALLANES-NOGUERA, CYNTHIA; MARCELA KURINA- SANZ

San Luis

Congreso; XIII CONGRESO ARGENTINO DE MICROBIOLOGÍA GENERAL; 2018

Universidad Nacional de San Luis

Chemical interconnection between plants and their endophytic microorganisms is fascinating. Itassessment offers, not only the possibility to understand the allelopathic mechanisms that determinethe equilibrium of this microcosm, but also to devise biotechnological tools to produce biocompounds.Many of the secondary metabolites that endophytes biosynthesize in order to control their competitorsin vivo can be produced by in vitro cultures (1). These chemical entities, that naturally defend both theplant and its seeds from predators (2), show several bioactivities, mainly antimicrobial, therefore havepromising applications in agriculture (3). In this field, technological developments based on biologicalcontrol concepts, are appreciated to minimize the use of chemicals of synthetic origin in pest control(4). It is supposed that this kind of bioproducts would be less harmful to humans and environment,since they could act specifically toward particular pathogens; while other chemicals with broaderspectrum are often lethal to beneficial insects and microbes, as well as affect the food chain (5).The goal of this work is the detection of fungal metabolites with antifungal activity towardphytopathogens of agronomic interest species, from in vitro cultures of endophytic fungi.The antagonistic potential of three endophytic fungal isolates was evaluated by facing each other indual solid cultures. Fusarium solani Eb01 (6) was chosen due to its highest inhibition rate. Then, itsantagonistic activity was tested toward collection strains of Aspergillus flavus, Aspergillus niger,Sclerotinia sclerotiorum, Sclerotium rolfsii, Fusariumm oxysporum and Penicillium chrysogenum. Mostof the developments were affected by F. solani showing radial inhibition rates higher than 40 %. Theexception was S. rolfsii, which development was not altered by the presence of the endophyte. A.niger was chosen for further studies, therefore organic extracts were obtained from F. solani liquidcultures with and without elicitation with nonviable A. niger mycelium. The chemical profiles of bothextracts were analyzed by gas chromatography attached to a mass spectrometer detector (GC-MS)and the Minimum Inhibitory Concentration (MIC) evaluated toward A. niger by essays performed inmulti-well plates.