From Takikawa et al. (1989).;P. syringae pv. actinidiae is a Gram-negative, obligate aerobe, non-sporing rod. It occurs singly or in pairs or short chains and is motile by 1-3 polar flagella. Poly-§-hydroxybutyrate granules are not accumulated.;Colonies on nutrient agar are translucent-white, slightly raised, glistening, and round. At 27¡C colonies do not exceed 1 mm after 48 hours. On King's medium B, colonies are translucent and non-fluorescent under UV light, though Cunty et al. (2014) report some strains of Psa as being fluorescent. Growth factors are not required. The pathogen is in Group Ia of the LOPAT determinative scheme of Lelliott et al. (1966) being positive for levan production and the capacity to produce a hypersensitivity reaction in tobacco, and negative in tests for oxidase and arginine dihydrolase production and pectolytic activity.
Related crop
- Nicotiana tabacum
- Olea europaea
Related invasive species
- Pseudomonas syringae pv. actinidiae
Related Farm Practice
- Light
- Tests
- Production
- Pruning
- Girdling
Canes;In spring, extending canes can become water-soaked and exude a pale, translucent to dark reddish coloured ooze from lenticels of apparently healthy tissue. Small (1-3 mm) cracks form above olive-coloured, water-soaked lesions and exude gum. Lesions elongate and whole canes become necrotic.;Leaves;In spring, small, water-soaked spots form on expanding leaves. These become brown and angular with bright, chlorotic halos. On lower surfaces, translucent gum may exude from stomata.;Flowers;Most infected floral buds become brown and wither without opening. They may exude translucent gum. Sepals can become infected. Heavy flower buds may drop.;Trunks and leaders;Symptoms of canker are first observed in mid-winter when small droplets of ooze are produced. In late winter ooze increases in quantity and becomes reddish brown. When vines break dormancy, canker symptoms are revealed by gum exudation from natural openings, from cracks in the bark, and from pruning cuts. Bark in these areas is dark and dissection reveals that necrosis extends in underlying tissue beyond the externally visible discoloration. Trunks and leaders may be girdled. Prolific suckering occurs below girdling cankers (Serizawa et al., 1989, Balestra et al., 2009).