الفهرس 
ACKNOWLEDGMENTSOnly 14 pages are availabe for public view
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Abstract
The current investigation was carried out in 2016 and 2017 in the tissue culture laboratory (Department of Vegetable Crops) and molecular analyses in Biotechnology laboratory (Department of Genetics), the Faculty of Agriculture, Assuit University, using the potato cv ’Cara’. Toward establishing quality in vitro potato transplants production, the study assessed phonotypical alterations of shoot growth and rooting in addition to genetic stability as expressed by pertinent molecular analyses. The phonotypic parameters included branching percent, number of branches/culture, main shoot length, number of stem nodes/culture, rooting percent and number of roots/plant. The molecular analyses comprised DNA markers (RAPD, ISSR and SRAP) and electrophoretic protein patterns. The explants used in this study were the single stem nodal segments. The stem single node cultures of potato cultivar ’Cara’ were followed-up for three shoot multiplication cycles (subcultures) on medium supplemented with 0.5 or 1.0 mg/l benzyladenine (BA) or lacking the BA. The data revealed that BA had a significant effect on all phenotypic parameters. However, the shoot multiplication cycle showed significant effect only on main shoot length and number of roots/plant. Shoots on BA containing medium as compared to those on medium lacking BA were shorter, developing multiple shoot branches and producing larger number of stem nodes/culture (single nodal explant yield). The stem nodal yield increased by 87.5% and 131.3% in cultures on medium supplemented with 0.5 and 1.0 mg/l BA, respectively. The multiplication rates were 3.2, 6.0 and 7.4 for medium lacking BA and medium-containing 0.5 and 1.0 mg/l BA, respectively. On the other hand, cultures of nodal explants derived from shoots propagated on BA containing medium exhibited an interrupted root formation. No roots formed after the second shoot multiplication cycle when used nodal explants from shoots formerly grown on medium with 1.0 mg/l BA. In the third shoot multiplication cycle rooting did not occur when used nodal explants from shoots harvested from cultures on medium with 0.5 and 1.0 mg/l BA. The correlation coefficients (r) numerated strong negative associations between rooting parameters and branching percent, branch number and nodal explants yield. The molecular assay was confirmatory to the phenotypic assay and the different marker methods used were reliable in assessing tissue culture-induced variations. An existence of amplified polymorphism, relative to the donor plants, in presence of BA and with increased the number of shoot proliferation cycles is suggested. Overall results are against in vitro use of BA in potato cv Cara shoot multiplication and transplants production media. Check of genetic stability at close intervals is advisable.
Keywords: ISSR, micropropagation, RAPD, SRAP, soluble protein banding, transplants production.
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Advisory committee:
Prof. Dr. Mohamed F. Mohamed Prof. Dr. M. H. Aboul Nasr Dr. Dalia M. T. Nassef