الفهرس | Only 14 pages are availabe for public view |
Abstract This study was conducted to use the tissue culture techniques to propagate ornamental Ipomoea batatas plants via estimating the appropriate concentrations of applied plant growth regulators to achieve the best micropropagation. The used plant materials were nodal segments explants were conducted at the Plant Tissue Culture Laboratory of the Plant Production Department, the Faculty of Agriculture Saba-Basha, Alexandria University, during the period from 2018 to 2019. This study to find out the appropriate micropropagation protocols for abovementioned species using nodal cutting technique. Respecting the initiation stage (starting stage) nodal segments were cultured on MS medium (1962) fortified with (BA) at three concentrations: 0.0 (nil), 0.50 and 1.0 mg/l, in combinations with auxin Naphtaleneacetic acid (NAA) at four concentrations: 0.0 (nil), 0.5, 1.0 and 1.5 mg/l. As for multiplication stage, the neoformed propagule of the initiation stage was sectioned into single leaflets nodes. The excised nodal cuttings were subcultured onto the multiplication media (i.e. MS-basal-medium) which supplemented with BA at four concentrations: 0.0 (nil), 0.5, 1.0 and 2.0 mg/l, in combinations with NAA at three concentrations: 0.000 (nil), 0.125 and 0.250 mg/l. The obtained shoots of Ipomoea batatas from the multiplication stages were, individually separated or excised and subcultured on MS medium (1962) augmented with two types of auxins, IBA at four concentrations: 0.000 (nil), 0.125, 0.250 and 0.375 mg/l, in combinations with NAA at three concentrations: 0.000 (nil), 0.125 and 0.250 mg/l, the produced plantlets were established ex vitro and in vivo (as concluded from the obtained results). However, the means of the following characters were determined after 35 days of growth, for Ipomoea batatas: number of neoformed shoots, shoot length (cm), number of nodes & leaflets and roots per propagule. However, the main obtained results of this study can be summarized as follows: 5.1 Influence of different concentrations of sodium hypochlorite and mercuric chloride on surface sterilization efficacy The obtained results indicating that using chlorox (commercial bleach) at 40% (v/v) achieved the highest percent survival (90%) compared to the other treatments which reflected on contamination percent (%). In this respect, using 1.00 mg/l of mercuric chloride, led to the highest percentage of survival of uncontaminated explants, i.e. 80% and 20% for contamination percent. The combination between sterilants, chlorex and mercuric chloride at 40% and 1.00 mg/l, orderly brought about was the highest percent of survival (100%). 5.2 Micropropagation 5.2.1 Initiation stage The highest mean values for the studied characters were always recorded at the precense of NAA from the culture medium (1.00 mg/l). On the other hand, the main effect of BA tested levels on the above-mentioned traits, commonly, as BA levels increased the given characters decreased. Concerns the interaction between NAA at 0.1 mg/l and BA at nil level, led to the highest mean values of the studied characters |