Valentina Di Pauli, Myriam A Canseco, Nicanor O Zalazar, Maximiliano G Olmos, C Nahuel Mieja Andrada, Luciana Martínez Calsina, Luis E Erazzú and Paola D Fontana
National Institute of Agricultural Technology (INTA), Experimental Station Famaillá, Tucumán, Argentina; dipauli.valentina@inta.gob.ar
Over the past 15 years, red stripe (RS) has become a major plant disease in Argentina, causing severe infections in susceptible sugarcane varieties with up to 30% yield losses. Control relies on the development of tolerant sugarcane varieties to replace the susceptible ones. Therefore, understanding the genetic diversity of Acidovorax avenae could provide valuable information for improving disease diagnosis and developing an accurate screening protocol to detect tolerant genotypes in breeding populations. The aim of this study was to identify and characterize a set of new isolates from Jujuy, Salta, and Tucumán provinces in order to enhance and complete the typing of A. avenae in the sugarcane-growing region of northwestern Argentina. By combining classical microbiological techniques and molecular methods, such as species-specific PCR and RAPD, we isolated, identified and genetically characterized A. avenae from leaves showing symptoms of RS. All isolates exhibited the typical morphology of Acidovorax on culture media, were Gram-negative, and oxidase-positive, and reproduced symptoms in a susceptible sugarcane variety. For all strains, the specific DNA fragment was amplified using primers for A. avenae. Polymorphic RAPD profiles were observed among isolated strains from different producing regions, confirming the expected diversity pattern. The findings on genetic diversity will be valuable for developing red stripe disease-tolerant sugarcane varieties.