Análisis histológico foliar de cítricos agrios y naranja dulce con síntomas ocasionados por Candidatus Liberibacter asiaticus

espanolEn Mexico, la enfermedad del Huanglongbing (HLB), provocada por Candidatus Liberibacter asiaticus, se reporto por primera vez en 2009 y tiene prevalencia mayor en citricos agrios. No hay reportes formales de la respuesta histologica asociada con la expresion del sintoma foliar en citricos agrios. El objetivo de este estudio fue caracterizar los cambios anatomicos e histoquimicos asociados con sintomas de HLB en hojas de limon persa (Lp) (Citrus latifolia), limon mexicano (Lm) (C. aurantifolia) y naranja dulce (Nd) (C. sinensis). arboles sintomaticos y asintomaticos en huertos de los estados de Nayarit, Colima y Yucatan, Mexico, se seleccionaron en julio del 2010 y el progreso de la enfermedad se evaluo durante seis meses en un brote por arbol. El area y anchura del floema, area del sistema vascular y area de tejido con almidon y proteinas se analizaron por parcelas subdivididas. Los sintomas macroscopicos se presentaron con mayor rapidez en Lm, a partir de punteado clorotico hasta amarillamiento y abscision foliar. El floema de la nervadura central en hojas sintomaticas de Lm mostro mayor hiperplasia (p EnglishIn Mexico Huanglongbing disease (HLB), caused by Candidatus Liberibacter asiaticus, was reported for the first time in 2009 and has mainly prevailed in sour citrus. There are no formal reports of histological response associated to foliar symptom expression in sour citrus. The objective of this study was to characterize the anatomical and histochemical changes related to HLB symptoms in leaves of Persian lime (Lp) (Citrus latifolia), Mexican lemon (Lm) (C. aurantifolia), and sweet orange (Nd) (C. sinensis). Symptomatic and asymptomatic trees were selected in orchards of Nayarit, Colima, and Yucatan, Mexico, in July 2010, and the progress of the disease was assessed during six months in one sprout per tree. Area and phloem width, area of vascular system and the mesophyll tissue with starch and proteins were analyzed by split plots. Macroscopic symptoms appeared more rapidly in Lm, starting with chlorotic spots unto yellowing of leaves and foliar abscission. The phloem of the central nervure in symptomatic leaves of Lm showed major hyperplasia (p