Pseudomonas viridiflava is a fluorescent, Gram-negative, soil bacterium that is pathogenic to plants. It was originally isolated from the dwarf or runner bean, in Switzerland. Based on 16S rRNA analysis, P. viridiflava has been placed in the P. syringae group. Following ribotypical analysis misidentified strains of Pseudomonas syringae pv. ribicola (which infects Ribes aureum) and Pseudomonas syringae pv. primulae (which infects Primula species) were incorporated into this species. This pathogen causes bacterial blight of Kiwifruit.
Kiwis are grown in countries such as Italy, New Zealand, China, and Chile making this bacterium a problem in kiwi-growing regions across the world. Kiwis have a long growing season from the beginning of spring to the fall which indicates that kiwis grow in warmer temperatures, but colder temperatures are important for the leaves to fall of the vine and for new buds to form in the spring. The pathogen, Pseudomonas viridiflava, was first discovered in kiwifruit in New Zealand in 1973.[4] It has been discovered on 31 other plant species such as tomato, melon, eggplant, and blight.[5] Symptoms on each host differ slightly, but in general, this bacterium causes a soft rot in the stem or flowering structures, not in woody tissues, which results in these structures turning brown and dying.