Possible infection routes of Ralstonia pseudosolanacearum race 4 in ginger plants were determined after either rhizomes that were cut for planting or roots of whole plants were inoculated with green fluorescent protein (GFP)-tagged strains. GFP signals appeared at budding sites but not cut surfaces of rhizomes. After root inoculation, strong GFP-signals were detected at rooting sites on the rhizomes, and the tissue was severely degraded at these sites. In both tests, bacteria spread from mother to seed rhizomes. These results suggested that the root and the budding site are major entry sites. [ABSTRACT FROM AUTHOR]