Primer reporte Kretzschmaria zonata (Lév.) P.M.D. Martin causando pudrición de la raíz en Tectona grandis L. en Costa Rica

Diseased trees were found in Tectona grandis plantations in the province of Guanacaste, Costa Rica, showing symptoms of collar and root rot. At the morphological and molecular level, the species Kretzschmaria zonata was identified as the causal agent of the disease. The pathogen's mycelium grew in a concentric form on PDA medium, with a gray coloration in the center and a white one at the edges. Dark brown ascospores were recorded, measuring (21.6-) 27.4 – 32.1 (-33.5) x (6.2-) 8.7 – 10.9 (-11.8) µm. Plants inoculated with the pathogen developed lesions, with highly significant differences compared to control plants. Re-isolations were performed, and the fungus K. zonata was recovered, fulfilling Koch’s postulates. This is the first time that this pathogen has been reported as causing disease in teak forest plantations in Costa Rica, which constitutes an advancement in the study of management strategies regarding this disease.