Dohou, N.

Douira, A.

Ouazzani Touhami, A.

Outcoumit, A.

Yamni, K.

Firenze University Press: E-Journals

40 Phytopathologia Mediterranea
Phytopathol. Mediterr. (2006) 45, 40–42
DISEASE REPORTS
Pyrus mamorensis Trabut is a Rosaceae endemic
in the Mamora forest (north-western Morocco) that
can reach 7 meters in height. This tree is common-
ly named the pear tree of Mamora and its vernac-
ular name is Njache. It is also considered a rare
species (Fennane et al., 1998).
A survey done in the Mamora forest in the
spring of 2003 and 2004 revealed that 60% of the
leaves of P. mamorensis had lesions that were of
two types. The first type of lesion was central, small
(2 to 3 mm), rounded and nearly black. The second
was large (10 to 15 mm) peripheral, diffuse and
black (Fig. 1).
Infected leaves were examined in the laborato-
ry with a filter-paper technique to detect the fungi
associated with the lesions. Washed leaves were
incubated in moist chamber for 48 h at 251°C
under continuous light (white fluorescent tubes).
Lesions were microscopically examined and the
First report of Pestalotia subcuticularis on Pyrus
mamorensis in Morocco
KHALID YAMNI, NAIMA DOHOU, ALI OUTCOUMIT, AMINA OUAZZANI TOUHAMI and ALLAL DOUIRA
Laboratoire de Botanique et de Protection des Plantes, UFR de Mycologie, Département de Biologie,
Faculté des Sciences, B.P. 133, Université Ibn Tofail, Kénitra, Morocco
conidial masses on the sub-epidermal acervuli were
inspected. The conidia were taken with a capillary
tube and placed on a PDA medium with the same
temperature and lighting as above.
After 8 days, the mycelium of the growing colo-
nies was branched, septate, hyaline, and yellow-
ish-white in color. The conidia were fusiform formed
of 5 cells, 20–29.16 µm5–7 µm. The three central
cells were blackish-brown and thick-walled (Fig.
2a). The apical and basal cells were hyaline, fine-
walled. The conidia germinated from the second
basal cell (Fig. 2b).
On the basal side, the conidiophore length was
5–11 µm. Two to 5 hair-like appendages (setae)
were observed on the apical side, free, not
branched, length 20–30 µm. the conidia with three
or four setae were abundant; those with two setae
were rare. The fungus was identified as Pestalotia
subcuticularis Guba (1961). Opportunistic fungi as-
sociated with the lesions were a Cladosporium sp.,
Rhizopus sp., Penicillium sp.
Some other species of Pestalotia have been re-
ported in Morocco as infecting other species of
Pyrus: P. communis, P. funerea, P. guepini and P.
laurocerasi (Rieuf, 1969).
Corresponding author: A. Douira
Fax: +212 037 372770
E-mail: douiraallal@hotmail.com
41
First report of Pestalotia subcuticularis on Pyrus mamorensis in Morocco
Vol. 45, No. 1 April, 2006
Fig 1.  Leaves of Pyrus mamorensis infected with Pesta-
lotia subcuticularis.
Fig. 2. (a) Conidia of Pestalotia subcuticularis; (b) germinated conidia.
Fig. 3 (a, b). Symptoms in leaves of Pyrus mamorensis artificially inoculated by conidial suspension of Pestalotia
subcuticularis.
Koch’s postulates were verified by inoculating
healthy leaves of P. mamorensis with P. subcuticu-
laris in spring and fall using two techniques. Half
of the leaves were inoculated with mycelial disks,
the other half with a conidial suspension adjusted
to a final concentration of 105 conidia ml-1 with ster-
ile distilled water containing 0.05% Tween 20 and
0.5% gelatin. The leaves were placed in 120-mm
Petri dishes containing small glass beads and ster-
ile distilled water. Inoculated leaves were kept in
the laboratory at 281°C under black plastic sheet-
ing that was removed after 24 h.
When the leaves were inoculated with the co-
nidial suspension the symptoms appeared after 24
h:  the lesions were black, rounded or slightly ellip-
tic and can cover a substantial part of the leaf (75%)
(Fig. 3a and b). When the leaves were inoculated
a b
a b
42 Phytopathologia Mediterranea
K. Yamni et al.
with mycelial disks, the same type of lesions oc-
curred (9.5 mm diam.). Seven days after inocula-
tion P. subcuticularis produced conidia abundantly
on the leaves of P. mamorensis inoculated both by
the conidial suspension (11.2105 conidia cm-2) and
by mycelial disks (9.7105 conidia cm-2).
On the leaves in spring, the central lesions ap-
peared more slowly with a smaller size, and were
at least faintly rounded and black. Lesions on the
periphery, on the other hand, were more extensive,
black and diffuse. On the leaves in the fall, symp-
toms development was faster, with the same le-
sions as in spring. The fruits of P. mamorensis that
had been inoculated with the mycelial disks did
not present any obvious symptoms.
In periods of drought, P. mamorensis is put un-
der stress by human activity and livestock graz-
Accepted for publication: February 16, 2006
ing, and attacks by P. subcuticularis can be one of
the reasons for the declining health of this tree over
the long term.
Literature cited
Fennane M., M. Ibn Tattou, F.M. Raimondo and B. Valdés,
1998. Catalogue des Plantes Vasculaires Rares, Men-
acées ou Endémiques du Maroc. (F.M. Raimondo, B.
Valdés, ed.), Published under the auspices of OPTIMA
by the Herbarium Mediterraneum Panormitanum ‘Boc-
conea’, Palermo, Italy, 8, 243 pp.
Guba E.F., 1961. Monograph of Monochaetia and Pestalo-
tia. Harvard University Press, Cambridge, MA, USA,
342 pp.
Rieuf P., 1969. Parasites et Saprophytes des Plantes au Ma-
roc. Les cahiers de la recherche Agronomique. Direction
de la recherche Agronomique. Ministère de l’agriculture.
Royaume du Maroc. Rabat, Morocco, 357 pp.


First Report of Pestalotia subcuticularis on Pyrus mamorensis in Morocco

K. Yamni

N. Dohou

A. Outcoumit

A. Ouazzani Touhami

A. Douira

Directory of Open Access Journals

First Report of <em>Pestalotia subcuticularis</em> on <em>Pyrus mamorensis</em> in Morocco

First Report of Pestalotia subcuticularis on Pyrus mamorensis in Morocco

Abstract

Similar works

Full text

Available Versions

Firenze University Press: E-Journals

Directory of Open Access Journals