Identification and caracterization of Colletotrichum species associated with anthracnose of Annonaceous crops in the state of Alagoas, Brazil/Identificacao e caracterizacao de especies de Colletotrichum associadas a antracnose de anonaceas no estado de Alagoas

Anthracnose is an important disease of Annonaceae caused by Colletotrichum species. In Brazil, C. gloeosporioides is the only species associated with annonaceous crops, based only on morphological criteria. In view of this, the objective of this study was to identify and characterize species of Colletotrichum infecting sugar apple and soursop trees in the state of Alagoas, Brazil. Fifty-one isolates obtained from sugar apple and soursop leaves with typical symptoms of the disease were collected in the municipalities of Maceio, Palmeira dos Indios and Uniao dos Palmares. The isolates were inoculated in detached leaves of both crops and they were characterized by conidia and appressoria morphometry and also by sequence analysis of the ITS region. All isolates were pathogenic to both crops. According to the morphological characteristics, the isolates were separated into three distinct groups: M1, M2 and M3. M1 group was made up 32 isolates that were closely-related to C. gloeosporioides. M2 group was formed by 15 isolates with characteristics of C. boninense, while in the M3 group, with four isolates, the characteristics were typical of C. fragariae. The phylogenetic analysis also resulted into three groups (F1, F2 and F3), which in general agreed with the morphological data. The F1group included the isolates of the morphological M1 group, as well as reference sequences of C. gloeosporioides and C. fragariae. The F2 group, that clustered reference sequences of C. boninense, included the isolates of the morphological M2 group. Finally, F3 group included sequences of C. magna and other four isolates of this study. Thus, it is possible to prove that four Colletotrichum species cause anthracnose on sugar apple and soursop trees in the state of Alagoas: C. gloeosporioides, C. boninense, C.fragariae and C. magna).