Studies on host range and intrinsic antibiotic resistance pattern of Ralstonia solanacearum infecting ginger

Bacterial wilt caused by Ralstonia solanacearum is one of the major constraints in ginger cultivation. In order to know the host range of this pathogen, strains of R. solanacearum infecting ginger were collected from ginger growing tracts of Palakkad, Ernakulam and Wynad districts in Kerala. They were cross inoculated on solanaceous and cucurbitaceous vegetables All the isolates of ginger were found to produce wilt symptoms on tomato and brinjal. But they failed to produce symptoms on other hosts even after 21 days. In the other study, chilli isolate alone was found to produce wilt symptoms on ginger. The pathogenic bacteria were also screened for resistance against various antibiotics such as ampicillin, carbenicillin, chloramphenicol, gentamycin, kanamycin, nalidixic acid, rifampicin, streptomycin sulphate, tetracycline at various concentrations. Based on their sensitivity pattern, antibiotic markers were developed for each isolates.