Abstract :
Since 1987 a devastating disease has occurred in coriander in Germany,
characterized by dark-brown discoloration of blossoms and umbels.
water-soaked and brown spots on leaves and stems, seed decay and
willing. Infected tissue always contained large quantities of Gramnegative,
rod-shaped, motile bacteria with few polar flagella.Tests for
LOPAT reactions showed the bacteria to be positive for levan-production
and tobacco hypersensitivity reaction but negative for oxidase
reaction, rot of potato slices and arginine dihydrolase. The bacteria
failed to produce fluorescent pigment on Kingʹs medium B but revealed
a blue fluorescence after growing in a liquid medium without Fe"",
According to further standard nutritional, biochemical and physiological
tests the coriander pathogen belongs to Pseudomonas group la.
i.e. Pseudomonas .syringae. Also, the fatty acid composition revealed a
very close similarity to P.seuodomonas syringae. On Biolog plates the
coriander strains showed a uniform metabolic pattern and could clearly
be distinguished from other Pseudomonas syringae pathovars.
Typical hosts of Pseudomonas syringae pv. syringae were not infected
by the coriander pathogen. Also, most tested umbelliferae species
reacted resistant towards the pathogen. Typical disease symptoms, such
as persistent water-soaked lesions, were incited only a Coriandrum
sativum, Ammi majus and Levisticum officinale. The studies revealed
that the pathogen described is a separate pathovar of Pseudomonas
syringae not included in the approved list of P. syringae pathovars. The
name Pseudomonas syringae pv. coriandricola is proposed. Strain GSPB
1965 has been deposited in the NCPPB as pathotype strain (no. 3781),
