الفهرس 
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Abstract
This work was carried out in the Central Laboratory for Research and Development of Date Palm, Agriculture Research Center (ARC), Ministry of Agriculture, Giza, Egypt and Plant Biotechnology Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), Minufiya University during the period 2003-2007. The first was selecting strains like Azotobacter chroococcum, Klebsiella pneumoniae, Azospirillum brasilense and Bacillus megaterium and tested the ability to produce PGRs and making bioassay techniques coupled with high performance liquid chromatography(HPLC)and colorimetric assay to evaluate (PGRs) which formed by the selected strains to determining types and quantities of ( PGRs ) which can be used to our advantage for regulating the synthesis as suitable for us to obtain optimum production that requirements for plant growth and development. The second objective was use phytohormones which produced instead artificial hormones as a protocol in date palm micropropagation through somatic embryogenesis induced from shoot tip or leaf primordial explants, which were isolated from offshoot apex. In order to test the possibility to use supernatant of the strains, which are auxins over producer and\or cytokinin over producers in culture medium composition according to development stages for maximizing yield and to study the effect on each stage. The third definition the gene that control production of phytohormones especially auxin and/or cytokinin. Significant differences among estimates of optical density (OD) in spectrophotometer at 580nm after 48hrs which readings ranged from (1.1-0.19).
Klebsiella pneumoniae reached the maximum of the optical density (1.1) after 48hrs from incubation while Bacillus megaterium was (0.61), Azospirillium brasilense (0.53) and the lowest growth rate was (0.19) in Azotobacter chroococcum culture. IAA production ranged from (73- 35µg/ml)and the auxin production in Klebsiella pneumoniae culture which supplemented with tryptophan was reached to the highest IAA rate production (73µg/ml) followed by Azotobacter chroococcum supernatant with tryptophan which recorded (57µg/ml) and Bacillus megaterium with tryptophan gave (39µg/ml) the lowest IAA-production was (35µg/ml) with Azospirillium brasilense in the presence of tryptophan these results were recorded after 48h and may be the incubation period effected on the production of some strains. Azospirillium brasilense gave the greatest fresh weight which was (30.8 mg) followed by Bacillus megaterium (25.9 mg), Klebsiella pneumoniae (21.5 mg) and Azotobacter chroococcum was lowest fresh weight (17.3 mg).In this experiment fresh weight reflect the effect of cytokinin presence and based on this bioassay is consider Azospirillium brasilense the best strain in cytokinin production. Extraction and Determination of Phytohormones
HPLC(High Performance Liquid Chromatography) Assay IAA production ranged from (47µg/ml) by Klebsiella pneumoniae with tryptophan to (1.5µg/ml) in the absence of tryptophan. Also, Azotobacter chroococcum gave considerable amount with tryptophan (20µg/ml). The same behavior was in GA3 production , that the results clearly show the greatest effect of tryptophan on the production of GA3 which ranged from (66µg/ml) by using Klebsiella pneumoniae with tryptophan which followed by Azotobacter chroococcum with tryptophan (41µg/ml) but (2µg/ml) GA3 obtained by Bacillus megaterium with tryptophan it is obvious that the behavior of this strain was strange because .It gave amount from GA3 reached to (27µg/ml) in the absence of tryptophan. On the contrary of the other strains that may be due to use trypton in its medium. ABA production was neglected in both cases. The amounts of 2iPwere ranged from (41.6µg/ml) in Azospirillum brasilense with tryptophan followed by Bacillus megaterium tryptophan free (39.5µg/ml) and the lowest strain in production was Azotobacter chrooccum which gave (1.1µg/ml) in spite of presence of tryptophan. The greatest zeatin production was (22.5µg/ml) by Klebsilla pneumoniae and (11.4µg/ml)by Azospirillum brasilense with tryptophan but Klebsilla pneumoniae without tryptophan produce (0.3µg/ml) that reflect importance of presence tryptophan in its culture medium. Zeatin- ribosid production was non significant in all treatments. Regardless of adding Azospirillum brasilense and Bacillus megaterium supernatants free tryptophan to MS medium, the value of formed callus degree from shoot tip explants was significantly higher (3.5)with Klebsilla pneumoniae supernatant in presence of tryptophan followed by treatments Azotobacte chrooccum, Azospirillum brasilense with tryptophan and control which were (3.0) as compared with the others. Regardless of Klebsilla supernatant in the absence of tryptophan was found in the swelling(1.25).On the other hand, treatments including Azotobacte, Klebsilla and Bacillus with tryptophan showed significant higher mean values of swelling formation degree(3.25) in both types of explants as compared with the other treatments specially, without tryptophan. Both types of explants with Azospirillum in presence tryptophan produced lower browning degrees (0.5) than those treated with Azospirillum without tryptophan and Klebsilla either with tryptophan or without which gave (1.0). On the contrary, Azotobacte and Bacillus with tryptophan make great rate of browning (2.5). The significant higher number values of pro- and, matured embryos as well as of shootlets were obtained on MS medium supplemented with Azospirillum brasilense with tryptophan gave (30embryo)followed by Bacillus megaterium (26),(25)with tryptophan and without respectively, this results may due to the presence of cytokinin in this supernatants comparing with other treatments and the lowest number of matured embryos was (6 embryos) obtained from culturing on medium containing Klebsiella pneumoniae supernatant free tryptophan.