اسم المؤلف:
بان منــعـم عبد الرزاق تويــج
اسم المشرف:
سعدية حسن محمود | كاظم محمد ابراهيم الصميدعي
المستخلص:
This project was conducted in the plant tissue culture laboratory, Biotechnology Department, College of Science, Al - Nahrain University. It is aimed to increase the production of some secondary metabolites using physical and chemical elicitors in tissue cultures of Hypericum triquetrifolium L. and Solanum nigrum L. plants. The quality and quantity of phytochemicals were estimated using methanolic extracts of dried leaves and callus were analysed using HPLC. Callus was initiated on leaf discs cultured on Murashig and Skoog (MS) medium supplemented with 2,4 - Dichlorophenoxy acetic acid (2,4 - D) and Benzyl adinenine (BA) at concentrations of 0,0.1, 0.5, 2.0 or 5.0 mg/l for H.triquetrifolium callus initiation and Naphthalene acetic acid (NAA) at concentrations of 1.0, 2.0, 3.0, 4.0 or 5.0 mg/l and BA at 0.5, 1.0, 1.5, 2.0 or 2.5 mg/l for S.nigrum callus initiation. Results showed that the combination of 2,4 - D at 0.1 mg/l with BA at 0.5 mg/l was the most effective for callus induction percentage reached 90%. The highest mean fresh weight reached 64.33 mg for H.triquetrfolium, and the combination of NAA at 2.0 mg/l with 1.0 mg/l BA was the most effective for callus induction percentage reached 100% and the fresh weight reached 859.1 mg for S.nigrum. The same combination was used for callus maintenance for both plants. Results also showed an increase in the concentration of secondary metabolites in methanol extracts induced on leaves. Callus cultures induced on leaf discs were treated with some physical and chemical stimuli such as light, ultraviolet, jasmonic acid and salicylic acid, (2, 4, 6 or 8 mg/l jasmonic acid), or (50, 100, 150 or 200 mg/l salicylic acid), and different exposure to photoperiod (dark for 24 hrs, 12 hrs light, 16 hrs light or 24 hrs light), the uv exposure time was 10 or 20 minutes. Result showed that there are significant differences between the various treatmeant, the best concentration of jasmonic acid to stimulate and increase production was 6 mg/l in H.triquetrifolium callus cultures, and 8 mg/l for S.nigrum. Salicylic acid stimulated the production reached 150 mg/l in callus culture of H.triquetrifolium and 100 mg/l in callus culture of S.nigrum. The best light exposure time caused an increase in the production of secondary metabolism was 12 hrs light for calli in both plants. Both exposure time (10 or 20 mint) induced the yield of secondary metabolites in callus cultures of H.triquetrifolium equally. and 20 minutes for S.nigrum. It is concluded from studying the effect of chemical and physical treatments on callus of both plants. that uv increased callus fresh weight and secondary metabolites in callus cultures. The highest concentration of secondary metabolites induced incallus cultures of H.triquetrifolium were catchin (0.14708 mg/g), hypersoid (0.09825 mg/g), hypericin (0.84623 mg/g), pseudohypericin (0.13707 mg/g), hyperforin (0.85525 mg/g) and prenylated phlorglucin (0.11275 mg/g), the highest fresh weight for callus 61.67 mg. S.nigrum callus cultures produced ascorbic acid (0.14721 mg/g), α - solanine (0.2294 mg/g), solasodin (4.3689 mg/g), solanidin (1.4854 mg/g), β - solamargine (5.9896 mg/g), α - solamargin (1.5509 mg/g), solasonine (1.3048 mg/g) and demission (2.031 mg/g). Additionaly, it yielded the highest callus fresh weight reached 849.20 mg.
