Dieback and pod rot caused by Lasiodiplodia theobromae and L. iraniensis in native accessions of cacao (Theobroma cacao) from Amazonas, Peru

Lasiodiplodia spp. are known to cause canker, rot and dieback symptoms in several crops worldwide. In this study, two Lasiodiplodia species were identified as pathogens of native cacao accessions from the department of Amazonas, Peru, causing dieback and pod rot on young and old stems. We evaluated the macro and micro morphological characteristics, and conducted a molecular identification based on a phylogenetic analysis with a multilocus dataset with informative loci for the genus. Microscopic examination revealed the presence of immature conidia that were initially hyaline, subovoid, unicellular, and double-layered, which became reddish brown with a central septum and longitudinal grooves at maturity. In the phylogenetic analysis, we identified our isolates as L. theobromae and L. iraniensis with strong bootstrap support values. Koch's postulates were fulfilled after the re-isolation of the same species from diseased tissues of cacao fruits and stems after an artificial inoculation. Therefore, in this study, we report for the first time L. theobromae and L. iraniensis infecting native cacao plants in Amazonas, Peru.