Lasiodiplodia species diversity associated with coconut leaf blight and stem-end rot in Northeastern Brazil

Many abiotic and biotic factors can negatively affect the production and productivity of coconut cropping systems. The incidence of Lasiodiplodia species in crops can lead to significant economic losses due to the development of leaf blight and, consequently, both pre- and post-harvest stem-end rot of fruits. The management of these pathogens is complex, expensive and primarily depends, on the massive use of chemical products. In addition, decision making on effective control measures depends on the target pathogen. This work evaluated epidemiological aspects of Lasiodiplodia species, in association with the green dwarf coconut from Northeastern Brazil. The isolates were sampled in production areas located in the dry, sub-humid and humid climatic zones in the states of Pernambuco and Paraíba and were identified using multilocus phylogenetics with the tef1-α, ITS, tub2, and rpb2 regions. Lasiodiplodia theobromae was found in crops present in all three evaluated zones while L. pseudotheobromae was reported only in the dry zone of Pernambuco. All species were pathogenic to green dwarf coconut, with L. theobromae, L. pseudotheobromae and L. subglobosa being the most aggressive species. The recognition of L. theobromae, L. pseudotheobromae, L. brasiliensis and L. subglobosa, in coconut plants from Northeast Brazil, complements the scientific understanding about stem-end rot and leaf blight in coconut crop. Additionally, this study presents relevant information on the pathogenic characteristics of these species that can be used in future research into epidemiological factors, fungal resistance, phytosanitary management and genetic improvement.