First Report of Colletotrichum gloeosporioides on Strawberry in Northwestern Argentina

Abstract

Colletotrichum gloeosporioides was isolated from symptomatic strawberry (Fragaria × ananassa Duch. ‘Chandler’) growing in Lules (Tucumán, Argentina). Isolates were characterized based on several criteria. Potato dextrose agar (PDA) was used to evaluate cultural and morphological characteristics of the isolates. After 10 days on PDA at 28°C under continuous white light, colonies showed abundant aerial, cottony white to pale beige growth, with orange asexual fruiting bodies in older colonies. Isolates displayed cylindrical conidia, rounded at both ends, averaging 10.4 × 3.9 µm (length by width). A sexual phase (perithecia) was observed in all isolates in 2-month-old cultures on PDA at 28°C under continuous white light. Pathogenicity tests were conducted with healthy plants of cvs. Pájaro and Chandler. Spray inoculation with conidial suspensions (106 conidia per ml) resulted in disease symptoms (petiole and crown lesions with wilting of crown-infected plants) 7 days after inoculation. Infection progressed at a higher rate in Pájaro than in Chandler. Reisolations from infected strawberry lesions yielded isolates with characteristics identical to the isolate used to inoculate the host. Based on morphological and cultural characteristics, isolates were identified as C. gloeosporioides Penz. & Sacc. (teleomorph Glomerella cingulata Spauld & H. Schenk) (1). This is the first report of C. gloeosporioides causing strawberry anthracnose in northwestern Argentina. Reference: (1) P. S. Gunnell and W. D. Gubler. Mycol. 84:157, 1992.