Espécies de Fusarium associadas a sementes de maracujá

Abstract

The yellow passion fruit Passiflora edulis f. flavicarpa is originally from Brazil. Its fruit is widely accepted in the domestic and foreign markets, and can be consumed fresh or processed in the form of juices and jellies. In addition, it has many functional and medicinal properties. One of the most used methods to propagate passion fruit cultivars is through seeds. However, these same seeds can act as disseminators of important phytopathogens for the crop. Among the pathogens spread by the seeds, Fusarium spp. The present study aimed to investigate the presence of Fusarium spp. associated with passion fruit seeds, isolate Fusarium spp., perform the molecular identification of Fusarium isolates obtained and evaluate the pathogenicity of these isolates in passion fruit seedlings. To investigate the presence of phytopathogenic fungi associated with passion fruit seeds, a Blotter test was performed on different seed lots of P. edulis f. flavicarpa; the incidence of fungal genera in the seeds was evaluated and when the Fusarium genus occurred, isolation was carried out. The identification at the gender level was performed through morphological comparisons of the observed fungi. For the Fusarium genus, the molecular identification of the isolates was performed using Blast and phylogeny using the RPB2 and TEF1 regions. Pathogenicity test for Fusarium isolates was carried out, in this assay two inoculation methodologies, dipping and toothpick, were tested in two cultivars, Sol and Redondo Amarelo. The genera Aspergillus, Penicillium, Rhizopus, Colletotrichum, Paecelomyces, Cladosporium and Fusarium were found 24 Fusarium isolates were obtained and with the use of molecular tools and the use of the RPB2 and TEF1 gene regions, it was possible to discriminate them as belonging to the complexes of F. oxysporum and F. incarnatum-equiseti species. For the F. oxysporum complex, the phylogenetic tree was built using Bayesian interference, isolates FS05, F6, FSDr7, F19 were grouped in the same clade with the species F. fabacearum, F. callistephi, isolates FS02 and FS03 if grouped in the same clade with the species F. veterinarum, F. contaminatum, F. pharetrum. For the variable Incidence there was no significant difference (P > 0.05) between the isolates when inoculated via toothpick, the isolate FS01 when inoculated by dipping differed from the other isolates also inoculated by this method. The cultivar Redondo Amarelo had the highest incidence of the disease. And inoculation via colonized toothpick provided the largest lesion size in the seedlings.