Strains ofPseudomonas solanacearumAffecting Solanaceae in the Americas

Abstract

Of 85 strains of P. solanacearum from 10 countries in the Americas and from 4 solanaceous hosts, 28 strains were biotype I, 52 were biotype II, and 5 were biotype III. Biotype I was identified among strains from Brazil, Colombia, Costa Rica, Peru and the USA. Biotype III was found among strains from Costa Rica, Peru, and Brazil only; but none of the strains were from potatoes. Biotype IV was not found. Thirty representative strains were selected for pathogenicity tests on tomato (Lycopersicon esculentum ''Huando''), potato (Solanum tuberosum ''Ticahuasi''), and Nicotiana glutinosa. A total of 23 strains were pathogenic on all 3 hosts, by a soil infestation method. Biotype II had more pathogenic strains than biotype I under glasshouse conditions. Only one strain of biotype III, from tomato, affected potatoes.