INVESTIGADORES
CASTAGNARO Atilio Pedro
congresos y reuniones científicas
Título:
DIAGNÓSTICO MOLECULAR DE LOS PATÓGENOS CAUSANTES DE ROYAS MARRÓN Y NARANJA EN CAÑA DE AZÚCAR Y EVALUACIÓN DE GERMOPLASMA DE LA EEAOC CON MARCADORES MOLECULARES ASOCIADOS A UNA RESISTENCIA DE AMPLIO ESPECTRO
Autor/es:
RACEDO J.*; PERERA M.F.*; BERTANI R.**; GONZÁLEZ V.**; CUENYA M. I.***; D´HONT A.****; WELIN B.* Y CASTAGNARO, A. P.
Lugar:
San Miguel de Tucumán
Reunión:
Otro; XVIII Reunión técnica nacional de la caña de azúcar; 2012
Institución organizadora:
SATCA
Resumen:
Brown rust (Puccinia melanocephala), present in Tucumán since 1988, and orange rust (P. kuehnii), not yet reported in Argentina, cause yield losses in sugarcane all around the world. Due to the difficulty in distinguishing these two diseases by visual observation, it is essential to use specific diagnostic techniques. Besides, the most effective method for disease control is the use of resistant varieties. A major gene, Bru1, which confers resistance to a broad spectrum of P. melanocephala strains in several productive regions of the world, has been described and some molecular markers have been associated with it. This work aims to i) optimize molecular methods for diagnosis, characterization and population analysis of both pathogens and ii) assess the presence of markers associated with Bru1 gene in local breeding program germplasm. Thirty samples of sugarcane leaves with rust symptoms and leaf samples of 251 sugarcane genotypes were collected. Both conditions of nucleic acid extraction and amplification of rDNA with five primer pairs for diagnosis were optimized. All symptomatic samples were positive for P. melanocephala, as they amplified fragments of 670 bp (ITS1F/ITS4), 608 bp (NL1/NL4), 585 bp (PkPmF/PkPmR) and 480 bp (Pm1F/Pm1R). No amplified fragment was observed when the primer pair specific for P. kuehnii was used. These optimized protocols for P. melanocephala and P. kuehnii diagnosis constitute robust and specific diagnostic tools available for local growers. Fifteen out of the 251 genotypes analized for Bru1 associated markers were positive. Correlation between marker presence and resistance to the disease should be determined. This would enable an early, rapid and positive selection of this character in our breeding programs.