Caracterización morfológica y molecular del agente causal de la antracnosis en tomate de árbol en Azuay y Loja

Abstract

Anthracnose is a fungal disease that causes serious losses in tree tomatoes in Ecuador. This disease causes serious damage to fruits and its control is based mainly on use of chemical products. In Ecuador, the genera Colletotrichum acutatum and Colletotrichum gloeosporioides have been reported to be the causal agent of anthracnose, based on morphological characteristics. In this study, the morphological and molecular characterization of 16 isolates of Colletotrichum spp. of tree tomato, in six different localities in the provinces of Azuay and Loja. Morphological characterization was carried out for variables such as colony color and conidium shape, while molecular characterization was performed by polymerase chain reaction (PCR). PCR experiments was carried out with specific primers reported for C. acutatum and C. gloeosporioides, designed in the internal transcription spacer (ITS). Based on morphological and molecular characterization, it was determined that the causative agent of anthracnose for the provinces of Azuay and Loja is the C. acutatum complex, represented by C. tamarilloi. Isolates presented characteristics of this species and molecular analysis allowed to confirm this result, generating amplifications of molecular weights of approximately 500 bp, while with the specific primers of C. gloeosporioides no amplification was obtained. This molecular characterization confirms results that place the C. acutatum complex as the causative agent of anthracnose in the Southern region of Ecuador.