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Papaya anthracnose caused by Colletotrichum truncatum is reported for the first time in Brazil. The etiological agent was identified by a combination of morphological and molecular approaches. Pathogenicity was confirmed and Koch's postulates fulfilled for a selected isolate from Porto Seguro, Bahia, Brazil. Keywords fungal disease. occurrence. postharvest Papaya (Carica papaya) is among the most widely cultivated and consumed tropical fruits (Serrano and Cattaneo 2010). Among the main producers, México, Brazil, Nigeria, India and Indonesia, Brazil ranked second in 2017 for production volume, producing 1.4 tons on 30.000 ha (IBGE 2017). However, plant diseases lead to reduced productivity in the form of yield loss and have a detrimental impact on fruit quality (Ferreira et al. 2018; Martins and Blum 2014). Papaya yield losses are mainly attributable to phytopathogenic fungi, such as Phytophthora spp., Phoma caricae-papayae, Asperisporium caricae, Oidium caricae, and Colletotrichum spp. (Ventura et al. 2004). Anthracnose is among the most important papaya postharvest diseases due to the large losses in production, which may reach about 90% (Valenzuela et al. 2015). In January 2017, a disease was detected causing postharvest losses on papaya in Porto Seguro, Bahia, Brazil. Symptomatic ripe fruit presented brownish, rounded, necrotic and depressed lesions. Black acervuli were produced in

22 23 Colletotrichum is among the most important genera of fungal plant pathogens. 24 Molecular phylogenetic studies over the last decade have resulted in a much better 25 understanding of the evolutionary relationships and species boundaries within the 26 genus. There are now approximately 200 species accepted, most of which are 27 distributed among 13 species complexes. Given their prominence on agricultural 28 crops around the world, rapid identification of a large collection of Colletotrichum 29 isolates is routinely needed by plant pathologists, regulatory officials, and fungal 30biologists. However, there is no agreement on the best molecular markers to 31 discriminate species in each species complex. Here we calculate the barcode gap 32 distance and intra/inter-specific distance overlap to evaluate each of the most 33 commonly applied molecular markers for their utility as a barcode for species 34 identification. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), histone-3 35 (HIS3), DNA lyase (APN2), intergenic spacer between DNA lyase and the mating-36 type locus MAT1-2-1 (APN2/MAT-IGS), and intergenic spacer between GAPDH and 37 a hypothetical protein (GAP2-IGS) have the properties of good barcodes, whereas 38 sequences of actin (ACT), chitin synthase (CHS-1) and nuclear rDNA internal 39 transcribed spacers (nrITS) are not able to distinguish most species. Finally, we 40 assessed the utility of these markers for phylogenetic studies using phylogenetic 41 informativeness profiling, the genealogical sorting index (GSI), and Bayesian 42 concordance analyses (BCA). Although GAPDH, HIS3 and β -tubulin (TUB2) were 43 frequently among the best markers, there was not a single set of markers that were 44 best for all species complexes. Eliminating markers with low phylogenetic signal 45 tends to decrease uncertainty in the topology, regardless of species complex, and 46 leads to a larger proportion of markers that support each lineage in the Bayesian 47 concordance analyses. Finally, we reconstruct the phylogeny of each species 48 complex using a minimal set of phylogenetic markers with the strongest phylogenetic 49 signal and find the majority of species are strongly supported as monophyletic.

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