Distinguishing pathovars of Pseudomonas syringae on peas: nutritional, pathogenicity and serological tests



Of the published methods to distinguish Pseudomonas syringae pv. syringae and Pseudomonas syringae pv. pisi, inoculation of susceptible cultivars was the most reliable. Results were confirmed by inoculation of lemon fruit.

A much more rapid and convenient serological method was developed to distinguish the two pathovars. Antisera against glutaraldehyde-fixed cells had a high level of specificity in Ouchterlony gel double-diffusion tests and, after cross-absorption with heterologous antigens, in indirect ELISA. Antiserum to P. syringae pv. pisi has considerable potential to detect pea seed infected with this pathogen.