Identification and virulence of Colletotrichum species causing anthracnose on mango

Abstract

AbstractSpecies of Colletotrichum cause severe anthracnose on mango (Mangifera indica). Many species of Colletotrichum with unequal frequencies on mangos have been revealed in many reports. The biological differences among Colletotrichum species are largely unknown. In this study, species of Colletotrichum were identified by phylogenetic analyses and their virulence was compared. The results revealed six species of Colletotrichum causing anthracnose on mango fruit in Taiwan; these species included C. asianum, C. fructicola, C. siamense and C. tropicale in the C. gloeosporioides species complex and C. sloanei and a new species, described here as C. pedunculi sp. nov., in the C. acutatum species complex. Among them, C. asianum was the most dominant species, accounting for 72% of the studied isolates. The virulence of each species was evaluated by inoculating unwounded fruits and young leaves with conidial suspensions. Notably, C. asianum was the only species with high virulence on both mango fruits and leaves. Additionally, the endophytic lifestyles of C. asianum and C. pedunculi sp. nov. in asymptomatic twigs and peduncles, respectively, were revealed. These results suggest that the high virulence and the endophytic lifestyle of C. asianum may explain its predominance among the Colletotrichum species on diseased mango fruits.