First Report of Colletotrichum acutatum on Strawberry in Northwestern Argentina

RAMALLO, PLOPER, ONTVERO, FILIPPONE, CASTAGNARO, AND DÍAZ RICCI

PLANT DISEASE

APS press

Año: 2000 vol. 84 p. 706 - 706

0191-2917

Isolates were obtained from strawberry tissue eith anthracnose symptoms from several locations near Tucum-an, Argetnina. Isolates were characterized using several criteria. Isolates produced fusiform conidia, tapered to a point at both ends, and averaged 13.5 x 4.9 um. On potato dextrose agar, colonies produced a white cottony mycelial colony that turned orange in older cultures. Compared with Colletotrichum fragariae, the new isaoltes produced fewer appressoria. Pathogenicity tests were conducted od detaches leaves and plants in the greenhouse and field. Chandler, Fer and Sweet Charlie were inoculated with a 20ul droplet of an aqueous conidial suspension (106 conidia per ml) placed on the adaxial surface. Control leaves were inoculated with sterile water. Leaves were maintained under white light (2,000 lux, 12 h/day) at 26ºC, and 100% relative humidity. Necrotic spots were visible 4 days after inoculation. Greenhouse and field plants were spray-served on petioles and runners 9 days after inoculation. No lesions were observed on control detached leaves or plants. Koch’s postulates were confirmed in all cases. Based on morphological and cultural characteristics, isolates were identified as C. acutatum Simmonds. This is the first reports of C. acutatum causing strawberry anthracnose in northwestern Argentina.