Characterization of Colletotrichum Species Causing Mango Anthracnose in Senegal

A number of species in the Colletotrichum gloeosporioides complex, as well as several additional Colletotrichum species, have been reported as causal agents of mango anthracnose. Although morphological characters are more commonly used for the identification of fungal species, these criteria are however often overlapping and variable. In such cases, a more reliable species identification is achieved with molecular characteristics, a trend with a huge development in recent years. In Senegal, mango anthracnose is very common in wet production conditions, likewise during the rainy season. However, no accurate identification of the causal species was made. To fill this gap, thirty isolates of Colletotrichum were isolated from anthracnose lesions of mango from several regions in Senegal. The isolates were identified and grouped based on colony morphology, as well as size and shape of conidia and appressoria. Several color variations were noticed among these isolates, with small differences in spore shape, spore size, and presence of black pigmentation in the colony. Sequence analysis of the rDNA internal transcribed spacer region indicated that all 30 isolates belonged to the C. gloeosporioides complex. Based on sequence analysis of the ApMat intergenic region, all of them were further identified as most closely resembling C. siamense.