Colletotrichum species associated with anthracnose disease on mango (Mangifera indica L.) cv. Azúcar in Colombia

The role of some Colletotrichum species is uncertain in crops of economic importance for Colombia such as mango (Mangifera indica L.) cv. Az & uacute;car. Eight Colletotrichum isolates from asymptomatic plant tissues were characterized by their pathogenicity on fruits and identified by phylogenetic analysis of the sequences of the ITS, GADPH, Tub2, CHs-1 and Act genomic regions. Colletotrichum asianum, C. gloeosporioides and C. tropicale of the C. gloeosporioides species complex and C. karstii of the C. boninense species complex were identified. The highest virulence was observed for isolates of C. asianum, that was the most prevalent species, and for C. tropicale, that showed high and intermediate virulence levels, indicating diversity in pathogenicity within the same species. The isolate of C. karstii, which displayed intermediate virulence, is the first report on mango in Colombia. Colletotrichum gloeosporioides presented intermediate virulence and was isolated at a low frequency in the present research. The mycelial growth rate did not show differences between species and ranged between 6.1 and 8.3 mm per day. Colletotrichum asianum recorded higher values of conidia germination and appressoria formation than other species, at 77% and 79%, respectively (p < 0.001). The shape and size of conidia did not vary between species. Appressoria exhibited different shapes between isolates and the largest average diameter was for C. karstii with 7.6 <mu>m (p < 0.001). There was a diversity of Colletotrichum species associated with mango cv. Az & uacute;car in Colombia, with differential virulence among isolates of the same species.