Page 54 - Volume 1, Issue 1, January 2008

K. Elena & A. Grigoriou 52
P. primulae causing brown core and root
rot of Primula polyantha. Tomlinson’s iso-
lates were also virulent to P. vulgaris, but not
to P. veris L. The new Phytophthora species
was very close taxonomically to P. syringae ,
but Tomlinson has distinguished P. primu-
lae by the formation of large sporangia and
mainly from the compound sporangia. Also
P. primulae has been recorded in New Zea-
land and Denmark, causing brown core of
P. polyantha (1). In our pathogenicity tests,
strains of P. primulae from parsley were
not pathogenic to primula plants. There
is only one report of P. primulae, causing
root and crown rot of parsley in UK (16).
Pathogenicity of P. cryptogea, P. citrop-
hthora, P. porri and P. nicotianae strains iso-
lated from other than parsley hosts was
tested on parsley since these species are
common to Greek crops. P. nicotianae and
P. cryptogea are described as parasites of
parsley (3, 9). There was a P. citrophthora
isolate that caused root rot of parsley in
Greece; however this isolate has been lost
(K. Elena 1993, unpublished data).
Phytophthora species identification is of-
ten difficult since morphology and growth of
isolates can be variable. Kouyeas and Chitza-
nidis (13) examined Greek isolates from citrus
peach and apricot trees, having a low maxi-
mum growth temperature and character-
ized these as Phytophthora syringae (Klebahn)
Klebahn, based on morphological charac-
ters. The isolates formed hyphal swellings
in a chain-like fashion reminding the figures
and descriptions given by Tomlinson (18) for
the compound sporangia of P. primulae . Ad-
ditionally, in the above isolates the chain of
swellings ended occasionally to a sporangi-
um, a character that brought them even clos-
er to P. primulae. These characters are obvious
in Fig. 2 of the respective article (13). Howev-
er these isolates did not form oogonia except
the citrus isolate, which produced abundantly
oogonia with paragynous antheridia only the
first period after their isolation. According
to Kouyeas and Chitzanidis the characters
that Tomlinson used to distinguish P. prim-
ulae from P. syringae did not seem strong
enough. We were not able to compare our
Table 2. Susceptibility of Petroselinum crispum plants to different Phytophthora species.
Phytophthora species Petroselinum crispum plants
Disease index
P. cryptogea BPIC1189 1
P. cryptogea BPIC1191 1
P. citrophthora BPIC1133 1
P. citrophthora BPIC1185 1
P. nicotianae BPIC2000 1
P. porri BPIC1985 1
Disease index (average of 15 replications), 1: no infection, 5: 100% infection.
Table 3. Susceptibility of different species to Phytophthora primulae.
Plant species
Phytophthora primulae
BPIC2584
Disease index
Malus domestica fruits 5
Solanum tuberosum tubers 1
Allium cepa bulbs 1
Disease index (average of ten replications), 1: no infection, 5: 100% infection.