Transcript Survey on Erwinia chrysanthemi Dickeya spp.

Survey on Erwinia chrysanthemi (Dickeya spp.)
in potato
Andrej Potočnik
Ministry of Agriculture and the Environment, Slovenia
Beograd, 22-23 April 2012
Identity and names
Preferred name: Dickeya chrysanthemi
Other name: Erwinia chrysanthemi
Arsenijević mentioned 6 pathovars, 1988 :
 E. ch. pv. chrysanthemi
Dickeya chrysanthemi
 E. ch. pv. dianthicola
Dickeya dianthicola
 E. ch. pv. Dieffenbachiae
Dickeya dieffenbachiae
 E. ch. pv. paradisiaca
 E. ch. pv. parthenii
 E. ch. pv. zeae
Dickeya zeae
Many of them are harmful organisms for potato, e. g.
D. dianthicola, D. zeae, D. chrysanthemi, D. dadantii…
2
Dickeya spp. - host plants and names of the
diseases
 There are a lot of quite different plant species as a
host of these harmful organisms.
 A big diversity is expressed also in the names of the
diseases they caused:
 Dickeya chrysanthemi
Bacterial wilt of ornamentals
 Dickeya dianthicola
Bacterial wilt of carnation,
bacterial wilt of dahlia, black leg of potato
 Dickya zeae
Bacterial stalk rot of maize, bacterial
soft rot of tobacco
 Dickeya dieffenbachiae
Bacterial leaf rot of
diefenbachie
3
Pest quarantine status

In the former Yugoslavia E. chrysanthemi had
been regulated as a quarantine organism.

It is placed in the EPPO A2 list:
 Dickeya (Erwinia) chrysanthemi or D. dianthicola
(E. chr. pv. Dianthicola)
The Data Sheet on this organism includes several
synonims connected with parthenii, chrysanthemi
and dianthicola
4
Pest quarantine status in EU
 Annex II.A.II (Organisms known to occur in the
EU and subject to control when found on certain
plants or their parts) – it is regulated if D.
dianthicola (E. ch. pv. dianthicola) would be
present on plants of Dianthus intended for
planting, other than seed
 Annex IV.A.I (Import from third countries) –
requirements apply only to the plants of Dianthus
species
 Annex IV.A.II (Movement within EU) – requirements
apply only to the plants of Dianthus species
5
Dickeya spp. – surveys and measures
 Other than references in Annexes II. and IV. and seed
potato marketing directive, there is no other planth
health regulative (directives or decisions) concerning
Dickeya spp..
 There is no legal basis for performing regular official
surveys for Dickeya spp., however, observation of this
pest is included into other potato surveys (ring rot,
brown rot, nematodes and potato wart disease).
 In the case of findings or outbreaks of this pest in
potato production there is also no legal basis for
ordering special phytosanitary measures, it is only
possible to issue recommendations.
6
Seed potato production regulation
 Council Directive 2002/56/EEC on the marketing
of seed potatoes is implemented by
 Rules on the marketing of seed potatoes (Official
Gazette of the Republic of Slovenia, No 105/06) –
SI seed potatoes certification scheme
7
Regulated conditions regarding black leg and soft rots of the potato tubers
at the seed potato production – allowed % of plants or tubers infected by
all causative agent of these disease (Erwinia spp., Dickeya spp…)
Allowed % of plants Allowed % by weight
in the field
of tubers before or
Seed category
during marketing
potato lots
Minimal EU
conditions
SI conditions for
seed potato
certification
Basic
2
1
Certified
4
1
Basic
0 – 0,1
0,5
Certified
0,5 - 1
0,5
Dickeya spp. – symptoms on the potato plants
 The tissue which is infected by Dyckeya spp. at
the begininng of infection is more or could be
brown. In the case of Eca the infected parts are
usually more black.
 The infected potato stem in the case of Dyckeya
spp. could be separated or interrupted by
undamaged tissue. There are infections or
symptoms just on the the upper parts of the
plants even just on the leaves. Eca causes lesions
which are uninterrupted.
9