FIRST REPORT OF ANTHRACNOSE ON CHERIMOYA CAUSED BY COLLETOTRICHUM TROPICALE IN CUBA

Abstract

Cherimoya (Annona cherimola Mill.) fruits with preharvest anthracnose symptoms were collected in Province Artemisa, Cuba, in April 2015. Necrotic, sunken lesions with orange spore masses were observed on 71% of the fruits. Single spore isolations on potato dextrose agar (PDA) were initially white and became light gray with scant aerial mycelium and abundant orange conidiomata in concentric rings. Conidia were 12.5-17.5 × 5-6.5 µm, subcylindrical with rounded ends, aseptate and hyaline, morphological characters consistent with Colletotrichum tropicale (Rojas et al., 2010). To confirm pathogen identity, the ITS region, the Apn2-Mat1-2 intergenic spacer and partial mating type (Mat1-2) gene (ApMat) and a partial sequence of the glutamine synthetase gene (GS) were amplified and sequenced (European Nucleotide Archive Accession Nos. LT853592, LT853593 and LT853594, respectively). A phylogenetic analysis using Bayesian inference with published ApMat, GS, and ITS data for Colletotrichum species in the C. gloeosporioides complex (Jayawardena et al., 2016) placed our isolate INIFAT 4144 in the C. tropicale clade. For assessing pathogenicity, five detached cherimoya fruits were inoculated with a suspension of 105 spores/ml by depositing 30 µl droplets of the suspension on the surfaces of nonwounded and wounded fruits with a sterile needle. Control fruits received sterile water. Typical anthracnose symptoms were observed in all inoculated fruits after 3 to 5 days. Control fruits presented no symptoms. The pathogen was consistently re-isolated from the infected fruits. To our knowledge, this is the first report of C. tropicale in Cuba and the first report on A. cherimola.