الفهرس 
1. IntroductionOnly 14 pages are availabe for public view
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Abstract
Commercial cucumber cultivars were explored for embryogenesis and plant regeneration induced in somatic tissues on plant growth regulators. An
efficient in vitro regeneration protocol for Cucumis sativus L. via somatic
embryogenesis has been developed. Embryogenic callus cultures were
established from mature seeds, cotyledons and shoot tips on Murashige and
Skoog (MS) medium containing 87.64 μM sucrose, 0.8% agar, 2,4-
dichlorophenoxyacetic acid 2,4-D and kinetin. Maximum callus induction
(94%, 92%) was observed in cotyledons and mature seeds on MS medium
supplemented with 1mg/l 2,4-D, respectively. Somatic embryos were observed
on mature seed explants after 17 weeks on MS medium supplemented with
5mg/l 2,4-D (33%) and 0.5mg/l α-naphthaleneacetic acid (NAA) (27%). while
somatic embryos were observed on cotyledon explants after 18 weeks on MS
medium supplemented with 2mg/l 2,4-D (10%) and 0.5mg/l NAA (25%). The
highest percentage of somatic embryogenesis (40%) was obtained with 2 mg/l
2,4-D and 0.5 mg/l NAA (30%) on shoot tip explants after 13 weeks.
Regeneration of adventitious buds from callus of cotyledon and mature seeds
were achieved after 8 weeks on MS medium supplemented with 0.5mg/l and
1mg/l 6-benzyladenine (BA), respectively. Generally, auxin was found critical
for induction of callus and formation of somatic embryos, while the cytokinin
was essential for callus differentiation and plant regeneration. Cucumber
explants (Cucumis sativus L. cv faris) were transformed by LBA4404 strain of
Agrobacterium tumefaciens harboring the binary vector pPZPnptCat-WMV.
The T-DNA region contained Neomycin Phosphotransferase II (NPT II) as a
selectable marker gene and sequence of Watermelon Mosaic Virus (WMV-II)
fused with GFP gene. Agrobacterium-mediated transformation was optimized
using GFP as a reporter gene. Optimized parameters were Agrobacterium
concentration, pre-culture period, co-cultivation period and immersion time.
Obtained results were based on the percentage of GFP expression.
Agrobacterium concentration at OD600nm 0.8, four days of pre-culture, three
days of co-cultivation and sixty minutes of immersion time gave the highest
number of GFP positive percentage (78%, 46%, 82% and 52%, respectively).
Cotyledon was the best explants to give the highest number of GFP positive
percentage in all tested parameters. Following co-cultivation, leaf, cotyledon,
callus and shoot-tip explants were cultured on selective medium containing 200
mg/l kanamycin + 300 mg/l cefotaxime. Kanamycin resistant shoots were
induced from these explants after four weeks. Putative transgenic plantlets were
obtained from leaf, cotyledon and shoot-tip explants after 8 weeks and after 12
weeks from callus. Molecular evidences by PCR demonstrated the effectiveness
of the transformation procedure. These results show that the Agrobacteriummediated
gene transfer system and regeneration via organogenesis is an
effective method for producing transgenic cucumber plantlets containing virus
sequences of WMV-II to confer resistance against this virus.