Phytophthora primulae
49
The length-breadth ratio varied from 1.3
to 2.4:1 (average 1.8:1). Sporangia consist-
ed of spherical or irregularly shaped seg-
ments with structures in chain fashion,
following the formation of septa at the
constrictions or delimitationof the sporan-
giophore, were also abundant in the cul-
tures (Fig. 2A, B, C). The protoplasmic con-
tents were often passed to the terminal
development, while the other segments
were empty (Fig. 2B, C). They measured 85-
390 x 7-45 μm. Tomlinson (18) called these
segmented bodies “compound sporan-
gia”. The isolates were omothallic, forming
oogonia abundantly on CMA, terminally
or laterally, 27-48 (average 37.5) μm in di-
ameter. Antheridia were mostly paragy-
nous, diclinous, often two per oogonium
and occasionally amphigynous, while the
young oospores were hyaline, average 32
μm in diameter (Fig.3). The maximum tem-
perature for mycelial growth was 26
0
C.
The morphological and physiological
characteristics of the causal microorganism
were consistent with the published descrip-
tions of
Phytophthora primulae
(16, 18).
RFLP analysis and PCR sequencing
All isolates yielded an equal size frag-
ment (~900 bp) when amplified with prim-
ers ITS6 and ITS4. Identical digestion pat-
terns were generated by BPIC1989 (
P. porri
)
and P1 (
P. primulae
) isolates which had been
Fig. 1.
Coiled hyphae of
Phytophthora primulae
from parsley.
Fig. 2.
Sporangia of
Phytophthora primulae
from parsley on soil extract A: compound sporangium with pronounced
constrictions B: sporangia and compound sporangium. C: compound sporangium, the protoplasmic contents were
passed to the terminal development of the sporangium.
A
B
C
Fig. 3.
Oogonium and oospores with paragynous antheridia, of
Phytophthora primulae
,
from parsley on corn meal
agar A: immature oogonium B: mature oospore. C: mature oospore with two antheridia.
A
B
C
1...,41,42,43,44,45,46,47,48,49,50 52,53,54,55,56,57,58,59,60