الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Wheat is one of the most important economical plants in the world and it is clearly a major component of the human diet. In Egypt, wheat production is decreased drastically and there is a broad gap between production and consumption due to infection with wide range of pests and pathogens. Many fungal pathogens that infect the spikes, leaves, and roots of wheat plants are responsible for substantial yield loss. A promising method for protecting plants against diseases is constructing and employing pathogen - resistant cultivars. Thus, there is a major focusing on wheat improvement through genetic engineering. Genetic engineering will provide an additional approach to enhance disease resistance.
5TThe development of plant transformation techniques during the last two decades has made it possible to improve economical crop plants by introducing into them cloned gene(s). Biolistic bombardment represents useful technique for successful delivery and functional integration of gene(s) of interest into plant genome. Therefor, the aim of the present work is the developing of Egyptian wheat cultivar with
improved disease resistance via the introduction of chi and 5Tnpr15Tgenes into genome of wheat cultivar Giza 164.
5T Chitinase hydrolyzes fungal cell wall chitin, thereby inhibits the growth of fungi, and generates chitin oligomers, which can act as elicitors of plant defense mechanism. On the other hand, 5Tnpr15Tgene plays a crucial role in systemic acquired resistance in plants.
5T The principal steps carried out during this work can be summarized in these points:
1- 5TImmature embryo derived calli of wheat cv. Giza 164 were co-transformed with the plasmid 5TpAHC255TP Pwhich contain the bar and gus genes and the plasmid 5TpAHC20Ubi3835T which contain the chi gene.
2- 5TImmature embryo derived calli of wheat cv. Giza 164 were also co-transformed with the plasmid 5TpAHC255TP Pwhich contain the bar and gus genes and the plasmid 5TpJS406 5Twhich contain 5Tnpr15Tgene.
3- 5TBiolistic bombardment technique was used to deliver the previous plasmids inside the wheat genome.
4- 5TGus gene was used as a re
7- 5Tporter gene. Histochemical analysis for bombarded calli was performed to study the gus gene expression.
8- 5TWheat bombarded calli transferred with chi gene were regenerated to selection media (CIMB, MSRB and FMSB) then 111 healthy regenerated plantlets out of 175 calli were transferred into soil pots for acclimatization in the control growth chamber. Only 55 plants succeeded in acclimatization and reached seed setting in 5Tbio- containment greenhouse.
9- 5TWheat bombarded calli transferred with 5Tnpr15T gene were regenerated to selection media (CIMB, MSRB and FMSB) then 105 healthy regenerated plantlets out of 161calli were transferred into soil pots in the control growth chamber for acclimatization. Only 48 plants succeeded in acclimatization and reached grains setting in 5Tbio - containment greenhouse.
10- TR0R 5Tplants acclimatized in the 5Tgreenhouse were submitted to preliminary screening by painting plant leaves with bialophos herbicide to confirm bar gene integration.
11-TR0R wheat 5Tplants were analyzed by polymerase chain reaction (PCR) using primers specific for both chi and 5Tnpr15T genes. PCR results revealed products of the expected sizes for all transgenes; 523 bp for chi gene, 439 bp npr1gene, 1050 bp for gus gene and 443 bp for bar gene.
12- 5TPCR analysis in the first experiment affirmed that a total number of 15, 17 and 11 plant’s transgene insertion were positive for gus, bar and chi genes respectively.
13- 5TPCR analysis in the second experiment affirmed that a total number of 12, 14 and 12 plant’s transgene insertion were positive for gus, bar and 5Tnpr15Tgenes respectively.
14- T5To confirm the integration of chi and 5Tnpr15T genes Dot - blot hybridization analysis was carried out.
15- 5TBoth PCR and Dot - blot analysis pointed to that the frequency of chi and 5Tnpr15T genes transformation process scored 1.8% and 1.9% respectively.
16- 5TAll produced plants were fertile and set seeds, which indicate that transgenes insertion did not, affected the fertility of plants or seed setting.