P-214 - Revealing the presence of Botrytis sp. 1 and Botrytis cinerea from Fragaria-Botrytis pathosystem in Chile

The commercial strawberry (Fragaria x ananassa) is a popular fruit crop cultivated in Chile. Gray mold caused by Botrytis cinerea is the primary threat worldwide and in Chile. Recently, several species of Botrytis have been reported in commercial strawberries in the USA and Germany. However, no scientific information is available on this disease's etiology in Chile. During the 2022-2023 season, asymptomatic and diseased fruits with gray mold were collected in Central-South Chile. The pathogens were isolated on Potato Dextrose Agar (PDA) medium. Of the isolates obtained (n=83), a subgroup of 12 isolates that presented white-cottony colonies were selected for cultural, molecular, and pathogenic characterization. Cultural characterization was performed according to the degree of sporulation in pea agar (AA) culture medium. Isolates were identified by multilocus molecular phylogeny through PCR amplification of fragments of the G3PDH, HSP60, and RPB2 genes. Pathogenicity tests were performed on strawberry fruits and leaves. The selected isolates did not present sporulation (0 conidia/cm2). Phylogenetic analysis indicated that eight isolates were grouped in an independent cluster of the total Botrytis species described (n=97), close to B. fabiopsis, B. caroliniana y B. galanthina. The remaining four isolates were identified as B. cinerea. All isolates were pathogenic on fruits and leaves of strawberry inoculated, producing lesions between 11.4 to 34.4 mm. Our results suggest the presence of a Botrytis sp. 1 associated with gray mold in Fragaria-Botrytis pathosystem.