Colletotrichum siamense as a causal agent of leaf anthracnose in seedlings of Annona muricata in nurseries from the Federal District, Brazil

Leaf anthracnose, caused by Colletotrichum siamense , was found for the first time in seedling nurseries of soursop ( Annona muricata ) in the Federal District, Central region of Brazil. Colletotrichum siamense was identified by morphology and by sequencing of the glyceraldehyde-3-phosphate dehydrogenase-GAPDH gene and the intergenic spacer between the 3′ end of the DNA lyase and the mating-type locus APN2/MAT-IGS. Moreover, etiology was confirmed by morphology, phylogenetic analysis of the concatenated sequences of the GAPDH and APN2/MAT-IGS DNA regions and pathogenicity of isolates in inoculation assays with soursop seedlings. This is the first report of the fungus C. siamense causing anthracnose on nursery seedlings of soursop in Brazil. The results of this work show that seedlings can be a source for the spread of C. siamense inocula into soursop commercial fields. In this way, the use of disease-free seedlings may be an important component in the soursop anthracnose disease management.