This study aimed to investigate the attitude of three nematode and phylloxera resistant grape rootstocks (Freedom, Ramsey and SO4) through the micropropagation stages till be micrografted by Superior scions. During that the effect of paclobutrazol (PP333) on rootstocks stem diameter, transverse sections in graft union regions and acclimatization of resulted micrografts were studied. The results proved that the most effective sterilization durations using 1% NaOCl were 15 min for Freedom and SO4 explants as they achieved 0.00 and 0.00%of  contamination and 100% and 90% of survival percentages respectively, while 10 min duration was sufficient for Ramsey explants as it achieved 0.00 % contamination and 100% survival percentages. Significantly, Ramsey achieved the highest number of shoots (1.25), Freedom gave the tallest shoots (4.13 cm)and SO4 got the highest leaf number (7.33) all on MS medium. In multiplication stage; Freedom rootstock proved to be the most reacted rootstock as it significantly accomplished the highest shoot number (2.00) when planted on BA medium, the tallest shoots (3.54 cm) when planted on TDZ medium and the highest leaf number on Kin medium. Whereas, in order to get thicker shoots for easier grafting; using of PP333 at 5 mgl-1 significantly was the best for Freedom (3.55 mm) followed by SO4 (3.03 mm) and Ramsey (2.85 mm) rootstocks. In micrografting stage, Superior micrografts significantly achieved the best results on rooted Freedom rootstocksin scion survival (100.00%) and on un rooted rootstocks in scion bud burst (75.00 %), graft union formation (50.00%), rooting (75.00%). On the same trend, Freedom rootstock was more active in cell dividing activity when grafted by Superior cultivar compared to Ramsey and SO4 rootstocks which were very poor in producing callus cells in graft union. Finally, Freedom rootstock grafted with Superior gained the highest survival (100%) after acclimatization.

calorie crop and commercially used as a non-caloric sweetener for diabetic patients. It is also used as cosmetic ingredient, pickling agent, and dentifrice. Four cultivars (Spantia, Shou2A3, China, and High Sugar) of stevia were included to optimize in vitro micropropagation. Four different combinations of hormonal treatments were investigated [6-benzylamino purine (BAP) + Kinetin (Kin) (0.25 + 0.25 mg/l); Forchloefenuron (Cppu) + Kin (0.25 + 0.25 mg/l); Cppu+ Kin (0.5+0.25 mg/l); and the control medium (hormone-free)]. Out of the different media components, the hormone-free medium produced the best performance of explants. The analysis of variance showed that the control treatment was the most significant for all traits except the number of branches per cutting. Hardening of rooted plants was performed in plastic pots with 70% survival percentage during acclimatization. Molecular characterization, of the four stevia cultivars, was conducted using 11 SCoT primers. The SCoT analysis resulted in 122 amplicons, of which, 62 amplicons (51%) were polymorphic. The range of polymorphism was between 6 % and 91 %. The range of polymorphic amplicons per primer was between one and 12 amplicons. The SCoT-16 produced the highest number of polymorphic bands (12). Meanwhile, the SCoT-24 produced the least polymorphism (6 %). The current study provides a new micropropagation system with low cost, high efficiency, and hormone-free application. Additionally, the study provides the first molecular characterization of stevia using SCoT marker system. Finally, SCoT markers associated with cultivars having high and low contents of stevioside can further be validated by marker-assisted breeding studies.

This reasearch work aimed to fine-tune micropropagation of Paulownia tomentosa in addition to assessing the genetic stability of in vitro raised clones from it. Paulownia tomentosa explants were surface sterilized using clorox (commercial bleach 5.25% sodium hypochlorite) at 10, 20, 25 and 30% + 0.5 g/l mercuric chloride (HgCl2) at different duration times, i.e. 10, 15, 20 and 25 min. In the multiplication stage, shoots were transferred to MS medium at ¾ strength containing BAP and Kin each at (0, 0.5, 1, 2, and 4 mg/l). Whereas, the rooting medium was MS medium at ¾ strength with IBA and NAA treatments each at 0, 0.5, 1, 2, and 4 mg/l. Sterilized explant with 30% Clorox for 20 min recorded highest survival percentage. The treatment of Kin at 4 mg/l gave higher significant shoot length. Whereas BAP application at 2 and 4 mg/l gave highest significant value of both shoot number and leaf number. Both IBA and NAA at 0.5 or 1 mg/l gave highest significant root number/shoot. Whereas, auxin at 4 mg/l gave highest significant root lengths. Young plantlets resulted from in vitro were acclimitized successfully in a mixture of peat moss: perlit (2: 1) by volume that showed 85.93% survival.  The genetic stability of in vitro raised Paulownia tomentosa clones was assessed by using intersimple sequence repeats (ISSRs) markers. All of the three ISSR primers screened, produced clear, reproducible and scorable bands.      The molecular size of Polymerase Chain reaction (PCR) products generated 22 fragments by these ISSR ranged from ≈460 to18660 bp. All banding profiles from micropropagated plants were monomorphic and similar to those of the mother plant, indicating 100% similarity. This confirmed the true to type nature of the in vitro raised clones.

The effect of benzyl adenine (BA) at 0, 2, 4, 6 and 8 mg l-1 on micropropagation of banana shoot tips was studied. This study also included the morphological responses of banana shoot tips especially with 0 & 6 mg l-1 of BA treatments in relation to some biochemical compositions (total soluble phenols, free amino acids, total soluble sugars, chlorophyll a, b and carotenoids). Growth in 6  mg l-1 of BA resulted in increase in the most morphological parameters compared to the rest treatments. The results showed that 6 mg l-1 of BA treatment significantly increased fresh and dry weights, number of shootlets, shootlet and root length and number of leaves and roots/plantlet as compared without BA. Accumulation of total soluble sugars, free amino acids and chlorophylls was enhanced by 6 mg l-1 of BA while the reverse was true with the rest biochemical compositions (total soluble phenols and carotenoids). The biochemical status and BA treatment at 6 mg l-1 during micropropagation of shoot tips in banana may be important for the development and optimization of strategies for large scale propagation and germplasm conservation.