الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
ate palm (Phoenix dactylifera L.) is a dioecious fruit tree native to the hot arid regions of the world, mainly grown in the Middle East, and North Africa. Date palm trees continue to provide the most sustainable agro-ecosystems in harsh dry environments providing raw materials for housing, furnishings, and many handcrafts in addition to supplying nutritious delicious fruits that can be consumed fresh, dried, or processed, providing a nutritious source of sugars, minerals, and vitamins ( Jain et al., 2011).
The limited availability of offshoots and the difficulties of establishing propogules from offshoots render this traditional propagation method inadequate, particularly for large-scale propagation. Based on recent advances in plant tissue culture, micropropagation technique has been developed for the rapid mass propagation of date palm. Some limitations associated with genetic improvement have been circumvented by taking advantage of tissue culture applications. (Al-Khayri and Naik 2017).
Micropropagation has great potential for the multiplication of female and male date palms of commercially grown cultivars by using inflorescences. This approach is simple, convenient, and much faster than the conventional method of using shoot-tip explants. The potential of inflorescence explants has been tested to develop direct and indirect formation of somatic embryos and organogenesis. (Khierallah et al., 2017)
Inflorescence explants have proved useful in avoiding many constraints that face shoot-tip explants, like high percentage of contamination, browning, and long initiation stage. Inflorescence-based micropropagation holds great potential for the multiplication of individual recalcitrant female and male date palms and cultivars of commercial interest and is particularly useful when offshoot availability is limited. This type of propagation can be accomplished in a short time with minimal effort as compared to the traditional practice of using shoot-tip explants. (Abul-Soad, 2011).
Introduction
Farid M. Rohim, (2021), Ph.D., Fac. Agric., Ain Shams Univ.
2
The term nanosilver means nanoparticles of silver ranging in size between 1 nm and 100 nm. Thus a single silver atom (Ag) or silver ion (Ag+) is not nanomaterial. A nanosilver particle may or may not be charged on its surface or generate silver ions. Like ionic silver, nanosilver is a very potent killer of bacteria and has been shown to kill fungi, algae, and some viruses, including HIV (Becker, 2000). Recently, nanosilver has been found at concentrations as low as 0.14 μg/ml to be toxic to several species of nitrifying bacteria, which play an important role in the environment by converting ammonia in the soil to a form of nitrogen that can be used by plants (Blaser et al., 2008). Interruption of cell wall synthesis, resulting in a loss of essential nutrients, has been shown to occur in yeasts (Wells et al., 1995) and may occur in other fungi as well. Antiviral activity of silver ions has been recorded, and interaction with –SH groups has been implicated in the mode of action (Thurman & Gerba 1989). Plant tissue cultures incubated in vitro emanate ethylene, and accumulation of this plant hormone in the culture vessel headspace may be unfavorable to culture growth. Explants are very sensitive to ethylene accumulation. Under in vitro culture of explants, ethylene causes slow growth, small leaf size, weak stems, and root formation on shoots (Ehsanpour & jones 2001). To overcome this problem, silver ion (Ag+) can be applied, as silver nitrate (AgNO3) or in the form of a silver thiosulfate (STS) complex, since it is an effective inhibitor of ethylene action (Beyer, 1979). Recently, strader et al., (2009) found that in addition to blocking ethylene signaling, Ag+ promotes indole-3-acetic acid (IAA) efflux. Silver added to the medium has been used to control and improve plant regeneration and transformation in vitro (Kumar, 2001 and 2007). Improvements were achieved despite the phytotoxicity of AgNO3 (Ratte 1999). Ag+ reacts not only with halide ions, but also binds to various compounds – such as lipopolysaccharides, amino acids, proteins, RNA, and DNA – to form silver nanoparticles, a property frequently used for biochemical analyses (Blum et al., 1987, Shevchenko et al., 1996).
Introduction
Farid M. Rohim, (2021), Ph.D., Fac. Agric., Ain Shams Univ.
3
Barhee an excellent variety from Iraq that has good features that it desires for consumption and expansion in its cultivation, which is increasing in Egypt, and there are examples of it in the various regions that cultivate, Palm description: the trunk is huge, the fronds are long, thick, the leaves are slightly curved, the wicker is long and wide, and some are drooping. The heels of the fronds are broad green, and the old ones are maroon edges. The thorns are about 1/5 the length of the fronds, and most of the thorns are double, the stalks are long and thick, yellow-orange, curved. Fruit description, the fruit in the Khalal phase is bright yellow. One cheek of the fruit tends to orange. Its taste is sweet, almost devoid of the astringent substance. This is why it is eaten in the Khalal and wet phase and dates, preferably wet over most types of dates. Fruit parts, the flesh is thick, free of fibers, with a delicious flavor. The maturity date is late October and November. The average palm tree yield is more than 150 kg.
Chitin is a natural polysaccharide, which consists of a copolymer of N-acetyl-D-glucosamine and D-glucosamine residues, linked by b-1,4 glycosidic bonds. It is present in a variety of species: in shells of crustaceans, in cuticles of insects and in the cell wall of fungi and some algae. The deacetylated form of chitin is chitosan. The chitosan biopolymer has applications in waste water treatment, pulp and paper, in medical and cosmetic products, biotechnology, food and feed and membranes ( Hirano, 1997). In agriculture, chitosan has been used in seed, leaf, fruit and vegetable coating (Devlieghere et al., 2004), as fertilizer and in controlled agrochemical release , to increase plant product to stimulate the immunity of plants , to protect plants against microorganisms and to stimulate plant growth .) Wanichpongpan et al., 2001). In the latter studies, a positive effect of chitosan was observed on the growth of roots, shoots and leaves of various plants including Gerbera (Hadwiger et al., 2002).
Introduction
Farid M. Rohim, (2021), Ph.D., Fac. Agric., Ain Shams Univ.
4
ZnO, CuO and γ-Fe3O4 nanoparticle structures are frequently used in nanofertilizer. It is possible to find the use of nanoforms of zinc, copper and iron in many studies and as a nanofertilizer on many different plants (Raliya et al., 2017). Because of these reasons, ZnO, CuO and γ-Fe3O4 NPs are usually subject to scientific study and it is very important to investigate the effects on living things.
The proportions of NP structures used to increase plant regeneration and the way of application do not seem to give the expected results. Nanostructures such as zinc, iron and copper, which can acquire different properties due to their size, cannot be effectively incorporated into metabolism and remain at a lower level of utility (Kumari, 2011).
The present study was set up to investigate the effect of Silver, Chitosan, Iron, Zinc nanoparticles also, some plant growth regulators on in vitro propagation of date palm cv. Barhee and seedling male immature inflorescences.