Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/15/2001
Publication Date: 6/1/2001
Citation: Abril, M., Curry, K., Smith, B.J. 2001. Anthracnose of strawberry ii:Trophic relationships of Colletotrichum acutatum and C. fragariae. Phytopathology. 91:S2.
Technical Abstract: Ontogeny of the infection process by Colletotrichum acutatum and C. fragariae was observed on petioles and stolons of the strawberry cultivar Chandler using light and electron microscopy. Plants were inoculated by misting with conidial suspensions (1,500,000 spores/ml) of C. acutatum and C. fragariae, incubated at 28 Celsius and 32 Celsius respectively and 100 percent RH, and tissue of petiole and stolon lesions were examined. Except for the faster and more aggressive nature of C. fragariae, no major differences were noticed between the two species. Following cuticular penetration via an appressorium, subsequent steps of invasion involve growth within the cuticle and within the cell walls of epidermal, subepidermal and subtending cells. Both fungi have a necrotrophic nature, but occasionally they penetrated living cells. Acervuli formed once the cortical tissue had been moderately disrupted and begun with the development of a stroma in the tips of the epidermal cells. Acervuli erupt through the cuticle and release conidia. Invasion of the vascular tissue apparently occurs after acervulus maturation and remains minimal.