Characterization of isolates of Xanthomonas axonopodis pv. manihotis - DOI: 10.4025/actasciagron.v28i3.965

Abstract

The bacterial blight (Xanthomonas axonopodis pv. manihotis) is the most important disease of cassava. To study the genetic variability of pathogen in the West of Paraná, a research was carried out at Entre Rios do Oeste, Marechal Cândido Rondon, Mercedes, Missal, Nova Santa Rosa and Pato Bragado. The isolates were characterized to amylase activity, α and β-esterase and aggressiveness. From 61 collected materials, were obtained 19 bacterial isolates, with larger incidence for varieties of human consume than those for industry. Stems from Pato Bragado, Entre Rios do Oeste and Mercedes showed incidences of 10, 27 and 10%, respectively, values smaller than those of Marechal Cândido Rondon (50%) and Nova Santa Rosa (58%). The isolates could be contained in five, six and twelve different groups to amylolytic activity, aggressiveness and esterase isoenzimes, respectively. There was not relationship between the amylase activity and aggressiveness. Marechal Cândido Rondon isolates were more aggressive than those of other sampled areas. According to the clustering for esterase, isolates from Entre Rios do Oeste, Nova Santa Rosa and Mercedes presented high similarity degree. According to the results, there is differentiation among the isolates of the bacteria presented in the studied regions.