sdu faculty of forestry journal special edition 2009 - Orman Fakültesi

SDÜ ORMAN FAKÜLTESİ DERGİSİ
Table 1: Pathogenicity of Pseudomonas syringae strains on poplar clone cuttings
Species / Hybrid Clone
165
Cuttings with visible damages (%)
P. syringae
strain 47
P. syringae
strain 48
control
Populus trichocarpa 30 21 (14) 1 0 (11) 0 (13)
Populus trichocarpa 872 33 (9) 25 (12) 0 (9)
Populus trichocarpa 936 27 (11) 45 (11) 0 (10)
Populus trichocarpa x P.
deltoides
Populus tremula x P.
tremuloides
Populus deltoides x P.
maximowiczii
Populus maximowiczii x P.
berolinensis
Populus maximowiczii x P.
nigra
995 29 (12) 18 (11) 0 (10)
L 211 56 (16) 79 (14) 8 (13)
960 56 (9) 67 (9) 13 (8)
Geneva 37 (8) 33 (9) 0 (9)
Rochester 44 (9) 60 (10) 11 (9)
1 in brackets: number of cuttings used for average
The limited number of cuttings as well as the fact that some cuttings did not
root resulted in the different number of replications per clone and treatment. Only
those cuttings were finally assessed regarding bacteria sensitivity, which showed a
sufficient root system. The inadequate rooting ability of the poplar clones can
could have induced water stress resulting in similar wilting symptoms like the
disease symptoms.
3. DISCUSSION AND CONCLUSION
P. syringae is a known pathogen on woody plants, not only in poplars, but also
in ash, willow, cherry, horse chestnut, and others. In recent time, to P. syringae
more than 50 pathovars were assigned. On woody plants, the pathogen causes bark
necroses with slime flux and canker. The newly-discovered pathovar of horsechestnut,
P. syringae pv. aesculi can act as a cambium destroyer with severe
dieback (Stobbe et al., 2008; Kaminski et al., 2007).