Comparative Study of Inoculation Methods to Determine the Aggressiveness of Xanthomonas citri pv. glycines Isolates and to Evaluate the Reaction of Soybean Cultivars to Bacterial Pustule

Bacterial pustule caused by Xanthomonas citri pv. glycines (syn. X. axonopodis glycines) is an important bacterial disease for soybean production worldwide. Currently, the planting of resistant cultivars main measure control disease. Therefore, objectives this study were to determine aggressiveness different isolates and establish a new protocol evaluate reaction under greenhouse conditions. The molecular analysis based on entire 16S rRNA gene sequence revealed that GDM 01, 02, 333 87-2 belong pathovar with 100% identity pathotype strain K29 bacterium. Differences in observed among isolates. There differences pustule, depending inoculation method. 333, 01 02 most aggressive, while 03 least aggressive ones. best conditions plants V3 vegetative growth stage inoculum concentration 108 CFU mL−1, moist chamber 24 h before after inoculation. Spraying without injury was quickest practical method screen genotypes resistance breeding programs. Further, closely simulates natural infection field produces typical symptoms standard brush overestimated severity, so we do not recommend evaluation