The Use of Fuller's Formamide Method in the Serological Identification of Pseudomonas solanacearum

Abstract

1. Fifty-nine extracts from cultures of Pseudomonas solanacearum from various countries and plant sources were tested serologically by Fuller's formamide method (ring test) with 9 antisera for different strains of the species. More than 99 percent of the tests were positive. 2. Exudate from stem pieces of tomato plants either naturally or artificially infected with Ps. solanacearum and showing symptoms of bacterial wilt was collected. Formamide extracts from the exudates gave a positive reaction with antisera for Ps. solanacearum. 3. None of the extracts in 1 or 2 above reacted with antiserum for two other bacterial species or with normal rabbit serum. 4. Use of the test in rapid serological identification of Ps. solanacearum as well as other phytopathogenic bacteria is suggested.