1. Specific Task Force COST 873 Determination of the Incidence of the Different Pathovars of Pseudomonas syringae in Stone Fruits Interested countries:Belgium Czech Republic Germany Hungary Latvia Lithuania Poland Slovenia The Netherlands Turkey UK

2. 1. The situation

9. RIPF Skierniewice

10. The bacterial canker of sweet cherry (Prunus avium) Naturally induced symptoms from which the pathogens were isolated were: Pseudomonas syringae pv. syringae : -Fruit spots -Leaf spots -Dead buds with limited progression in the branch -Blossom blast with limited progression in the branch -Only one report (France) of high progression in branches Pseudomonas syringae pv. morsprunorum race 1 -Fruit spots -Leaf spots -Dead buds and blossoms with high progression in branches -Infection of branches and trunk with high progression Pseudomonas syringae pv. morsprunorum race 2 -Fruit spots -Leaf spots -Canker (no information about the importance) Other Pseudomonas syringae or Pseudomonas viridiflava?

11. The bacterial canker of wild cherry (Prunus avium) Naturally induced symptoms from which the pathogens were isolated were: Pseudomonas syringae pv. avii -Infection of branches and trunk with high progression Pseudomonas syringae pv. syringae -Leaf spots -Cankers on branches and trunk (no information about the importance) Pseudomonas syringae pv. morsprunorum race 1 -Leaf spots -Cankers on branches and trunk (no information about the importance) Pseudomonas syringae pv. morsprunorum race 2 -Leaf spots Other Pseudomonas syringae or Pseudomonas viridiflava?

12. The bacterial canker of sour cherry (Prunus cerasus) Naturally induced symptoms from which the pathogens were isolated were: Pseudomonas syringae pv. syringae -Leaf spots -Fruit spots -Dead buds with limited progression in the branch -Woody tissues (no information about the importance) Pseudomonas syringae pv. morsprunorum race 1 -Leaf spots -Fruit spots -Dead buds with limited progression in the branch Pseudomonas syringae pv. morsprunorum race 2 -Leaf spots -Fruit spots -Dead buds with limited progression in the branch Other Pseudomonas syringae or Pseudomonas viridiflava?

13. The bacterial canker of plum Naturally induced symptoms from which the pathogens were isolated were: Pseudomonas syringae pv. syringae -Leaf spots -Blossom blast -Dead buds with limited progression in the branch -Only one report (Deutschland) of high progression in branches Pseudomonas syringae pv. morsprunorum race 1 -Leaf spots -Infection of trunk with high progression Other Pseudomonas syringae or Pseudomonas viridiflava?

14. In stone fruit orchards, several Pseudomonas syringae pathovars and races can be encountered in a same culture, several organs can be attacked, and the situation is complicated by the presence of epiphytic strains unable to cause disease living on plant surfaces. Pathogenicity tests performed in artificial conditions are not always a perfect imaging of the real potential of a pathogen in nature. Establish relations existing in Europe between specific disease symptoms observed in the orchards and particular pathogens isolated from the lesions is the main initial objective of the STF. 2. The aim of the STF

15. The situation in cherry and plum is very complex. Clear information doesn’t exist between the precise symptoms the five known pathogens are really able to induce in nature and about their relative importance in the different cultures (sweet cherry, sour cherry, wild cherry, plum). More information on these points would be useful at several levels: -improve our knowledge on the ecology of these pathogens, -better identify the most damaging organisms on each organ in each culture, for example in preparation of biological control, -better differentiate and classify these pathogens -allow for selection of correct strain in resistance breeding of stone fruit cultivars -… Some complexity also exist in peach Regrouping information from several European regions would give more value and universality to the results, compared to local data for one region or one country. This kind of work is thus well fitted within the frame of a COST project

16. 3. Progress to date STF Meeting on “Determination of the incidence of the different pathovars of Pseudomonas syringae in stone fruits” 27th-28th March 2008, Skierniewice, Poland (Organizer: Joanna Pulawska) Belgium Czech Republic Hungary Lithuania Poland Slovenia The Netherlands Turkey UK

17. - Only isolate strains from diseased plant material (no leaf washing …) or strains whose origin is sure - Careful description of the symptom observed: xylem (importance), cortical tissues (importance), dead bud, spots on leaves, expanding necroses on leaves, blossom blight (base of the pedicel), flower necrosis (problem in the flower and sepals), necroses on fruits (type of necrosis) - Strains named according to generally accepted methods of identification - LOPAT - GATTa tests - Pyoverdin-based identification tests - PCR cfl for coronatine production - PCR syrB and syrD + biological test for syringomycins and syringopeptins production - PCR irp1 (PSYE2-PSYE2R primers) for yersiniabactin production - Rep-PCR for stone fruit Pseudomonas syringae strains - Others - Determination of reference strains to use in identification - Standardization of the presentation of information Standardisation of work to fulfil the STF objectives

18. CountryScientistTotal IsolatesPlantIsolates Specific research programs BelgiumAlain Bultreys422Sweet cherry Sour cherry Wild cherry Plum 233 140 3 46 PolandJoana Pulawska Monika Sulikowska 200Sweet cherry Sour cherry Plum Peach 33 95 44 8 Interested scientists without specific funding Czech RepublicJaroslav Horky4Peach Sour cherry 3131 HungarySandor Sule2Sweet cherry2 LithuaniaMilda Vasinauskiene Daiva Burokiene ~ 10 TurkeyHatice Ozaktan7Peach7 Establishment of collections, present situation Specific research programs: Belgium: personal research program of A. Bultreys in the Walloon Agricultural Research Centre in Gembloux, and several past grants (F. Legros, V. Gilbert) from the Walloon Region, Head office of the Agriculture Poland: National project concerning Pseudomonas and Agrobacterium entitled “Phenotypic and genetic characteristics of bacterial pathogens of stone fruit trees, hazelnut and walnut”; will run up to 2011 (M. Sulikowska, J. Pulawska)

19. 4. Plan for 2009 Continuation of isolations and identifications in different countries STSMs STF meeting Thank you for your attention!