Bacterial rhizome rot of patumma and detection of seed-borne rhizome.
Extensive bacterial rhizome rot of patumma (Curcuma alismatifolia) caused by Ralstonia solanacearum (Rs) was found in Thailand. Host range studies found typical wilt symptoms occurred on patumma, ginger, tomatoes, egg plants [aubergines], peppers [Capsicum sp.] and marigolds [Tagetes sp.] but did not on sesame and tobacco. However, only Rs from ginger and sesame infected patumma. Patumma strains oxidized 3 sugar alcohols but did not utilized 3 disaccharides in biovar tests and they shared the same biochemical characters with strains of other hosts. Based on these characters, RS strains of patumma were identified as race 1 and biovar 4. Specific and sensitive detection of Rs was obtained at 102 cfu/ml by indirect immunofluorescent staining with a membrane protein complex antiserum of Rs.