الفهرس 
Effect of auxins type and concentration on survival %Only 14 pages are availabe for public view
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Abstract
Stevia rebaudiana Bertoni, is an important non-caloric natural sweetener plant used for the treatment of diabetes which is estimated to be 300 times sweeter than sugar cane. This work carried out in Plant Biotechnology Department Laboratories, Genetic Engineering and Biotechnology Research Institute (GEBRI), Sadat City, Egypt. An advanced protocol for tissue culture was established. Some factors affecting in vitro growth and development were studied (STS- BACalcium chloride, light and total darkness as well as type of culture container during multiplication stage and IBA and NAA during rooting stage). Shoot number was maximized with increasing of BAP concentrations through subcultures. Shoot number was not clearly affected by increasing STS concentrations; it ranged from 30 to 36 shoots/jar, but growth vigor was highly affected by increasing STS concentration. Shoot number and shoot fresh weight were enhanced by liquid medium supplemented with different CaCl2 concentrations. Also, culture containers; conical flasks; in both dark and light conditions increased shoots number compare with jar containers (88 and 80shoots/conical flasks and 48 and 68shoots/jar, in dark and light conditions respectively). Root percent possessed the highest values (100%) on MS medium supplemented with 0.25, 0.50 and/or 1.00mg/l IBA Rooted shoots were transferred to plastic pots (6 cm diameter) containing planting medium (peatmoss, perlite and sand at equal volume). Stevia plantlets grow well in greenhouse during acclimatization stage Various concentrations of growth regulators, BAP and NAA were examined for shoot proliferation and callus formation. The highest shoot proliferations resulted from 1mg/l BAP+0.5mg/l NAA. Effect of different NAA concentrations (0, 1, 2, 3, 4 and 5 mg/l) and various explants (nodes, normal leaves, vitrified leaves and roots) on calli formation and quality was examined. Vitrified leaves were the earliest callused explants when it was planted on 3mg/l NAA (21 days), followed by normal leaves (25 days) when it were planted on the same NAA concentration. Effect of different culture containers (tube, jar and cubic magenta) and various initial explants (nodes and leaves) on calli formation and quality were studied. The highest calli amount resulted from both explants when they planted in jars or cubic magenta. Shoot formation from leaves callus was observed on calli when transplanted to MS medium supplemented with 0.2 or 0.4mg/l 2,4-D On the other hand, calli differentiated to roots when culls were planted on MS medium supplemented with 0.4mg/l IAA. Every differentiated shoot has a genetic structure may be similar or a similar to the mother plants. DNA Finger printing of Stevia rebaudiana was conducted using RAPD and ISSR techniques for samples from in vivo plants (mother plants), in vitro plants (tissue culture plants), plants treated with STS in vitro and vitrified plants which used later in callus induction and differentiation. Similarity varied according to finger printing techniques and plant samples. Similarity relationship indicated that vitrified plants had a low similarity relationship with mother plants (53%) while, the closest similarity relationship conducted between treated plants with STS and tissue culture plants (72%).
These results could be very important in plant breeding and finding a new genetic structure to be used in plant breeding programs and plant development .