varieties creation and conservation of plant genetic resources

ehavior. The variety Sayali (Tunisia)
and Uljarica (Croatia) have expressed
high resistance after 13 days of
experimentation.
The Olive parlatoria scale:an emerging
pest in Tadla
The Study on the bio-ecology of
olive parlatoria scale (Parlatoria oleae
Colvée), an emerging olive tree pest
in the Tadla perimeter, indicated the
beginning of mobile forms since late
May with a maximum pullulating in
early July (Photo 12). A significant fruit,
rather than leaves, infestation was also
observed with the trend reversed during
the fruit maturity period.
Mapping and fire blight biological
control
The prospecting carried out in the
orchards of Azrou, El Hajeb, Immouzer
and Sefrou, revealed a wide spread of
fire blight disease in these areas.
Photos 12 : Symptom of Parlatoria oleae
attack on leaves and fruit.
The bacterium incidence was very
high. This year, the attacks were visible
on almost Pear varieties especially
Passe crassane, Morettini, Dr. j. Guyot,
William’s and Coscia. However, the
disease incidence on apple and quince
was more moderate, in contrast to
previous years when the quince was the
most affected.
Despite favorable climate conditions,
different varieties of apple have shown
significant tolerance levels. Moreover,
morphological and biochemical
characteristics of new strains of Erwinia
amylovora Burrill have confirmed the
presence of this bacterium. These results
were reaffirmed by the RT PCR which
gave a better diagnosis because of the
presence of the amsC and the aRN23S
genes in all strains (Figures 9 and 10).
Furthermore, the aromatogram method
highlighted the bactericidal effect
of essential oils of 12 medicinal and
Figure 9 : Result
of amsC gene
amplification by
PCR in real time on
a few strains of E.
amylovora collected
in 2010
Figure 10 :
Electrophoresis
Profiles of PCR
product in real time
during the aRN23S
gene amplification
on strains of E.
amylovora collected
in 2010
27 INRA 2010
Plants Protection