DETERMINACIÓN DEL AGENTE CAUSAL DE LA MUERTE DESCENDENTE DE HOJAS DE YUCA (Yucca filifera)

Abstract

Yucca filifera is a representative species of the flora of the arid regions of Mexico. It has several important uses, including as an ornamental plant, for reforestation on streets in urban areas, alcohol production, feed for livestock, birds and rabbits, as a raw material in the pharmaceutical industry for the production of hormones, extraction of high quality fibers for the textile industry, among others. Recently, plants with symptoms of dieback disease have been observed in leaves of Yucca filifera in different regions of Mexico, but until now the pathogenic agent involved was unknown, which jeopardizes this plant. In order to morphologically and molecularly determine and identify the causal agent of dieback disease in Yucca filifera leaves in Peña de Bernal, Querétaro. A 1 cm2 fragment was taken from leaves showing symptoms of dieback disease (disinfected prior to sampling) and inoculated onto potato dextrose agar (PDA) and incubated at 25 °C. Four days later, after the initial growth of the inoculated samples, monoconidial cultures were carried out in PDA. The fungus obtained was described morphologically using the electron microscopy technique. Then, molecular analysis was done and Koch’s postulates applied. The causal agent of dieback disease in Yucca filifera was concluded to correspond etiologically, morphologically, and molecularly with the fungus Kellermania macrospora.