The rhizome of ginger is most vulnerable to root rot infections caused by fungal genera. of Pythium and Fusarium. Secondly Ralstonia spp. in case of bacteria.
There are almost 15 varieties of Pythium; F. oxysporum. sp. zingiberi specific fungi is dominant in Fusrasium spp. and in bacteria Ralstonia pseudosolanacearum.
references:
Article A comprehensive review on soft rot disease management in gin...
Article Bacterial wilt of ginger (Zingiber officinale Rosc.) incited...
Ralstonia solanacearum causing bacterial wilt is the major bacterial disease whereas Pythium aphanidermatum causing rhizome rot is the major fungal disease in ginger.