Ice nucleation activity of some reference cultures of Pseudomonas syringae and field isolates of bacteria from wheat and barley in Queensland

When Australian reference cultures of Pseudomonas spp. and pathovars of P. syringae were examined for ice nucleation activity, 14/60 were positive, i.e., 314 isolates of P. syringae pv. pisi and 11/17 isolates of P. syringae pv, syringae. When bacterial isolates from wheat, barley and other grasses in Queensland were tested for ice nucleation activity, 1811 74 were positive of which 5 were P. syringae and 13 were identified using the API 20E system as a relatively uniform biotype of Erwinia herbicola. All but two of the E. herbicola isolates and all of the P. syringae isolates were isolated from wheat and barley at a single site, Wellcamp, near Toowoomba