Neopestalotiopsis sp. and Colletotrichum karstii, causal agents of leaf spots on camedor palm (Chamaedorea quezalteca) in Mexico

English. Abstract Since 2020, camedor palm (Chamaedorea quezalteca) plantations in the Frailesca region, Chiapas, Mexico, have been affected by foliar diseases that induce leaf spot and anthracnose symptoms that reduce production, leaf quality and thus the loss of their commercial value. The objectives of this work were to identify the causal agents and to quantify the incidence and severity of foliar diseases in plantations of camedor palm. Two fungi were recurrently isolated, one from leaves with leaf spot symptoms and the other with anthracnose, both were identified morphologically and molecularly by sequencing the internal transcribed spacer (ITS5/ITS4), pathogenicity tests were performed on healthy plants where fungal conidia were inoculated, and in the field the incidence and severity of the disease were quantified with the support of a pictographic scale. The fungi identified were Neopestalotiopsis sp. in leaf spot symptoms and Colletotricum karstii in anthracnose, both pathogens reproduced the same symptoms observed in the field, by means of pathogenicity tests. Disease incidence and severity percentages were transformed to area under the disease progress curve (AUDPC), these diseases presented an annual average incidence and severity of 35.33% (AUDPC= 14180) and 39.16% (AUDPC=12885) for leaf spot, 19.5% (AUDPC= 7123) and 55.83% (AUDPC= 20380) for anthracnose, respectively.

Spanish; Castilian. Resumen Las plantaciones de palma camedor (Chamaedorea quezalteca) de la región Frailesca, Chiapas, México, desde el 2020 son afectadas por enfermedades foliares que inducen síntomas de mancha foliar y antracnosis que reducen la producción, calidad de las hojas y con ello la pérdida de su valor comercial. Los objetivos de este trabajo fueron identificar los agentes causales y cuantificar la incidencia y severidad de las enfermedades foliares en plantaciones de palma camedor. De manera recurrente se aislaron dos hongos, uno de hojas con síntomas de mancha foliar y otro de antracnosis, ambos fueron identificados morfológicamente y molecularmente mediante la secuenciación del espaciador de transcrito interno (ITS5/ITS4), las pruebas de patogenicidad se realizaron en plantas sanas donde se inocularon conidios de los hongos, y en campo se cuantificó la incidencia y severidad de la enfermedad con apoyo de una escala pictográfica. Los hongos identificados fueron Neopestalotiopsis sp. en síntomas de mancha foliar y Colletotricum karstii en antracnosis, ambos patógenos reprodujeron los mismos síntomas observados en campo, a través de las pruebas de patogenicidad. Los porcentajes de incidencia y severidad de las enfermedades se transformaron a área bajo la curva del progreso de la enfermedad (ABCPE), estas enfermedades presentaron un promedio anual de incidencia y severidad de 35.33% (ABCPE= 14180) y 39.16% (ABCPE=12885) para mancha foliar, 19.5% (ABCPE= 7123) y 55.83% (ABCPE= 20380) para antracnosis, respectivamente.