Endophytic fungal communities isolated from two genotypes of feijoa fruits (Feijoa sellowiana O. Berg.) and prospection of potential agents against anthracnose pathogens

Feijoa sellowiana (O. Berg) Burret is a tropical fruit from South America known as pineapple-guava or feijoa. Anthracnose is a fungal-caused disease that harms feijoa, and may completely reduce fruit production. The endophytic microbiota of feijoa fruits from native cultivars may provide new biocontrol agents against anthracnose. This work aimed to evaluate the diversity of endophytic cultivable fungi in feijoa fruits from two Brazilian native cultivars and verify potential agents against anthracnose pathogens: Colletotrichum nymphaeae and Colletotrichum siamense. The cultivable fungal diversity in feijoa fruits was assessed by fungi isolation, fol-lowed by fungal identification, through sequencing the ITS region of rDNA, and estimation of species abundance and frequency. Later, the antagonism of selected isolates was tested against Colletotrichum spp. by direct confrontation. Results demonstrated that isolated fungal communities slightly differed between the two cultivars. There was no difference in the Shannon index between the two cultivars. However, abundance and frequency of endophytes was respectively, 40% and 53% higher in the most resistant cultivar (Mattos), where Trichoderma harzianum, Trichoderma hamatum, Clonostachys rosea and Clonostachys rhizophaga were exclusively found. C. rosea and T. harzianum from cultivar 'Mattos', and Talaromices amestolkiae found in both cultivars ('Mattos' and 'Alcantara'), reduced mycelial growth and sporulation of Colletotrichum spp. Therefore, the endophytic cultivable community was slightly more abundant and rich in the most resistant cultivar of feijoa by encompassing more antagonistic species of fungi. This work also described for the first time the potential of endophytic fungi as biocontrol agents of feijoa pathogens.