Distribución del Virus de la hoja amarilla de la caña de azúcar en Cuba

El presente estudio tuvo el proposito de determinar la distribucion del Virus de la hoja amarilla (Sugarcane yellow leaf virus, SCYLV), en diferentes provincias del pais y las variantes geneticas presentes. Se analizaron 35 campos (348 ha), de los cuales se tomaron 525 muestras de hojas en 13 cultivares comerciales. La deteccion del virus se realizo por Inmunoimpresion de Tejidos y por Reaccion en Cadena de la Polimerasa con Transcripcion Reversa (RT-PCR). Las muestras que resultaron positivas fueron utilizadas para identificar las variantes geneticas por RT-PCR con cebadores especificos. En la mayoria de las provincias fue alta la incidencia de sintomas asociados a esta enfermedad (82,29%). Se detecto, por primera vez, la presencia de este patogeno en areas comerciales de todas las provincias que cultivan la cana de azucar en Cuba. En la mayoria de los cultivares infectados, se observo el mayor grado de severidad de los sintomas, asociada a esta enfermedad. Se determino la presencia de tres variantes geneticas de SCYLV: BRA-PER, CUB y REU. Tambien se observaron infecciones mixtas de los genotipos BRA-PER + CUB y BRA-PER + REU. Palabras clave: hoja amarilla de la cana de azucar, SCYLV, distribucion geografica, variantes geneticas. DISTRIBUTION OF THE SUGARCANE YELLOW LEAF VIRUS IN CUBA ABSTRACT: The present study had the purpose of determining the distribution of the Sugarcane yellow leaf virus (SCYLV) and its genetic variants occurring in different provinces of the country. Thirty five fields were examined (348 ha), and 525 samples of leaves were taken in 13 commercial cultivars. Detection of the virus was carried out by Tissue Blot Immunoassay (TBIA) and the molecular analysis by Reverse Transcription- Polymerase Chain Reaction (RT-PCR). The positive samples were used to identify the genetic variants by RT-PCR with specific primers. In most of the provinces, the incidence of symptoms associated with this disease (82.29%) was high. This is the first time that this pathogen has been detected in commercial areas of all the provinces where sugarcane is cultivated in Cuba. In most of the infected cultivars, the highest severity grade of the symptoms associated with this disease was observed. The presence of three genetic variants of SCYLV was determined: BRA-PER, CUB and REU. Mixed infections of the genotypes, BRA-PER + CUB and BRAPER + REU, were also observed. Key words: Sugarcane yellow leaf virus , SCYLV, geographical distribution, genetic variants.