Análisis filogenético multilocus del complejo fúngico asociado a pudrición radicular de sandía en Sonora, México

The state of Sonora is one of the main producers of watermelons in Mexico. Each year, agricultural producers deal with phytosanitary issues like soilborne pathogens. In this study the presence of phytopathogenic fungi associated to watermelon root rot was analyzed in the main production regions of Sonora. Morphological analysis revealed three genera: Fusarium (73%), Ceratobasidium (20%) and Rhizoctonia (6%). Through a multilocus phylogenetic analysis (ITS1, TEF and RPB2 for Fusarium ; ITS1 and RPB2 for Rhizoctonia and Ceratobasidium ), the following species were identified: Fusarium falciforme, F. brachygibbosum and F. oxysporum . In addition to this, two anastomosic groups for Ceratobasidium sp. (AG-F y AG-A) and two for Rhizoctonia spp. (AG-4 y AG-6) were identified. Pathogenicity assays showed that the representative isolates from these five different species caused root rot wounds and wilting in watermelon plantlets 21 days post inoculation. In this study, F. falciforme is reported for the first time and anastomosic groups for Rhizoctonia and Ceratobasidium are defined as causal agents of watermelon root rot in the region.