Patogénesis de la antracnosis (Colletotrichum fragariae) en frutos de chirimoya

The pathogenesis of Colletotrichum fragariae Brooks on immature cherimoya fruits (Annona cherimola Mill.) was studied because the stages of this process, as well as the anatomical changes induced by the fungus on this crop are unknown. Conidia germinated on the epidermis and trichomes, and formed a globose or clavate appressorium 6-9 h after inoculation. The fungus induced the production of polyphenols in epidermal cells and in those of the parenchyma, but the infection did not cease. Penetration was direct through epidermal cells and trichomes 24 h after inoculation. Colonization of the fungus in the mesocarp was inter- and intracellular. Later cells collapsed and necrosis set in. The fungus formed short conidiophores, free or grouped in subcuticle and subepidermal acervuli in the damaged tissue. C. fragariae completed its disease cycle in 72 h in healthy, immature cherimoya fruits.