الفهرس 
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Abstract
Name of Candidate: Farida Farouk Kabil Degree: Ph.D.
Title of Thesis: Improvement of strawberry plants using tissue culture
techniques.
Supervisors: Dr. Mohamed Abdel-Mageed Badawi
Dr. Khaled El-Sayed Ali
Department: Vegetable Crops
Approval: 12 / 7 /2009
ABSTRACT
The experiments of the present study were conducted in the Tissue Culture Lab.,
Department of Vegetable Crops, Faculty of Agriculture, Cairo University, Giza, Egypt,
during the period from 2005 to 2008. The objectives of this work were to improve
strawberry plants using tissue culture techniques by developing a successful protocol for
tetrahaploid production in strawberry cvs Camarosa and Sweet Charlie using anthers and
unpollinated ovaries, and select new strains from these cvs tolerant to salt stress in vitro.
Closed floral buds (2-4 days before anthesis) were pre-treated at 4°C for different periods
and cultured their anthers and ovaries on different media composition. Embryogenesis
was performed from both anthers and ovaries and multiplication was induced to produce
new shoots. Shoots were rooted and produced whole plantlets for adaptation. Results
showed that cold pre-treatment was not efficient for producing the best ovule regeneration
and production of tetrahaploid plants and both cultivars gave nearly similar results under
the optimal conditions for ovule regeneration. On contrary, anthers needed 24 h cold pretreatment
for producing embryogenic calli with cv. Sweet Charlie. Determination of
ploidy level was carried out and examinations showed that plantlets produced from the
ovule culture were tetrahaploid but 8 plantlets from 11 produced from anther’s
embryogenic calli were tetrahaploid and the rest were octaploid. For achenes, achenes
were isolated from strawberry mature fruits of the studied cvs, stored in dark at 4 °C for
different periods and exposed to scarification by hydrochloric acid followed by
sterilization and rinsing in sterile distilled water for different periods. The germination
percentage was 95% with cv. Camarosa and 97% with cv. Sweet Charlie after 5 weeks of
cultivation combined with one month cold storage pre-treatment in dark at 4°C and 4h
rinsing period at 10°C, in both studied cvs without significant differences between them.
Based on the results obtained on embryogenesis of both anthers and ovaries, and achenes
germination, the best medium and the best conditions for each explant were used in
salinity experiment by adding Rashedy salt to the chosen media. The highest
concentration of Rashedy salt for treating ovaries that produced embryogenesis, shoot
multiplication, recovery and adapted plantlets was 5000 ppm and cv. Sweet Charlie was,
significantly, the best for producing salinity tolerant plantlets in vitro from ovaries culture.
Only 2 plantlets from cv. Sweet Charlie succeeded to be stable under 5000 ppm after
acclimatization in the greenhouse. All plants produced from achenes in all salt
concentrations were not able to overcome these concentrations in the greenhouse. The
effect of salt stress on strawberry genetic stability was allowed to be examined through
RAPD test and both of the tolerant strains of cv. Sweet Charlie were have genetic
variation when compared with the original plants by using RAPD-PCR.
Keywords: strawberry - Fragaria - anther culture - ovary culture - embryogenesis -
androgenesis - gynogenesis