Phylogeny, identification and pathogenicity of the Botryosphaeriaceae associated with collar and root rot of the biofuel plant Jatropha curcas in Brazil, with a description of new species of Lasiodiplodia

The global expansion of cultivation areas of Jatropha has contributed to the emergence of various diseases. Currently in Brazil, the occurrence of a new disease has been reported that not only reduces the productivity but also causes the death of Jatropha. This disease is associated with collar and root rot of plants. From morphological and phylogenetic studies (based on Internal Transcribed Spacers, beta-tubulin and Translation Elongation Factor 1-alpha sequences), nine species of Botryosphaeriaceae were identified. These species include Lasiodiplodia egyptiacae, L. pseudotheobromae, L. theobromae, Macrophomina phaseolina, Neoscytalidium hyalinum and four Lasiodiplodia spp. that are proposed as new species (L. euphorbicola, L. jatrophicola, L.macrospora and L. subglobosa). All the species in this study, except M. phaseolina, are pathogenic. The results show that root rot of physic nut plants is caused by complex pathogens. This study provides new information for future studies of disease management, quarantine programs and, especially, the development of resistant varieties for collar and root rot disease in J. curcas.