Identification of new hosts for Ralstonia solanacearum (Smith) race 2 from Colombia

Ralstonia solanacearum Smith induces the Moko disease on banana, plantain and heliconiaflowers. The objectives of this work were: I) to identify R. solanacearum hosts in weeds or cultivated hostsand II) to determine its pathogenicity on the susceptible host plantain cv. Dominico-Hartón. A survey in searchof natural hosts of R. solanacearum race 2 was performed in selected Colombian regions. Sixty bacterialcolonies showing R. solanacearum characteristics in a semi-selective medium were used in further pathogenicitytests in the susceptible plantain plants. Twenty six isolates induced Moko disease symptoms in plantain duringthe 60 days of evaluation. Twelve new hosts were found for R. solanacearum at the worldwide level: nine ofthem were weeds (Euphorbia graminea Jacq., Blechum piramidatum Lam., Oxalis latifolia Kunth, Cupheamicrantha Kunth, Eleusine indica L., Gliricidia sepium Kunth ex Steud., Lobelalia xalapensis Kunth,Stachys lamioides Benth., Salvia aff. lasiocephala Hook. & Arn.) and three cultivated crops (Colocasiaesculenta L., Cucurbita maxima Duchesne and Psidium guajava L.). The presence of R. solanacearumrace 2 in weeds and cultivated crops should be managed as an important component of an integrated Mokodisease control program