sp. nov.: A New Species Causing Black Pod Disease on Cacao in Brazil.

Black pod disease, caused by species, is among the main limiting factors of cacao ( L.) production. High incidence levels of black pod disease have been reported in Brazil, being induced by , , , and . To assess the diversity of species affecting cacao in Brazil, 40 new isolates were obtained from cacao pods exhibiting symptoms of black pod disease collected in different smallholder farms in 2017. Further, ten cacao-infecting isolates morphologically identified as and were molecularly characterized. The genomic regions beta-tubulin, elongation factor 1 alpha, heat shock protein 90, and internal transcribed spacer, and the mitochondrially encoded cytochrome oxidase I and II genes were PCR-amplified and Sanger-sequenced from the cacao-infecting isolates. The morphological characterization and evaluation of the mycelial growth rates for the isolates were performed . Based on the molecular analysis and morphological comparisons, 19 isolates were identified as (clade 4). Interestingly, 31 isolates grouped together in the phylogenetic tree and were placed apart from previously known species in clade 2. Therefore, these isolates are considered as a new species herein referred to as sp. nov., which produced papillate, semipapillate, and persistent sporangia on simple sporangiophores. The isolates were identified as A1 mating type by pairing each isolate with known A1 and A2 tester strains of , but no oogonia/antheridia were observed when was paired with the different tester strains. The and isolates showed higher mycelial growth rates, when compared to , on different media at 10, 15, and 20°C, but similar values were observed when grown on clarified CA media at 25 and 30°C. The pathogenicity tests carried out on pods of four cacao clones (CCN51, PS1319, Cepec2004, and CP49) showed significant variability among the isolates of both species, with inducing higher rates of necrotic lesion expansion, when compared to . Here, two species were found associated with black pod disease in the state of Bahia, Brazil, and the previously undescribed seems to be prevalent in field conditions. This is the first report of on . Also, these findings are crucial to improve the disease control strategies, and for the development of cacao materials genetically resistant to .