جستجوی مقالات مرتبط با کلیدواژه "شاخه زایی" در نشریات گروه "باغبانی"

This study was conducted to investigate the effect of different concentrations of agar and carbohydrate on micro-propagation of dwarf cherry rootstock (PHL-C) under in-vitro conditions in 2017 year. This experiment was conducted as factorial in a completely randomized design with six replications and three plantlets in each replication. The first factor was agar in three levels (0.5, 0.6, 0.7%) and the second factor was carbohydrate in six levels (sucrose and sugar each in 3 levels of 20, 30, 40 g / l) and evaluated in proliferation, rooting and adaptation steps. The single node was used for propagation The results showed that there was no significant difference between different agar concentrations in terms of proliferation index, rooting percentage, plantlet quality, plantlet fresh weight and survival percentage, but in other measured traits, agar with concentration of 0.7 % had the best results. Except in the traits plantlet height, leaf number and plantlet fresh weight which the sucrose had a more positive effect, in other traits there was no significant difference between sugar and sucrose. Due to the fact that in the essential traits of in vitro propagation of PHL-C, sugar has a better effect, it is suggested to use table sugar or a combination of sugar and sucrose to reduce the cost of producing the culture medium, especially in commercial production.

Silybum marianum L., from fam. asteraceae, is a very important medicinal plant in the pharmaceutical industry due to its active ingredient silymarin. Silymarin is very effective in treating the liver diseases, hepatitis, and cardiovascular disorders. Since the potential and production speed of this medicinal compound is low in habitats under natural conditions, the use of genetic engineering and production of transgenic plants using the various techniques such as tissue culture has been considered in this plant. The first step in this direction is to obtain an in vitro regeneration protocol. In this study, the leaf explants obtained from the Hungarian cultivar of S. marianum were evaluated for the direct regeneration affected by different combinations of hormones. Six weeks after the culture, the highest shooting (57%) was observed in the ½ MS medium containing 0.4 mg l-1 zeatin, 0.2 mg l-1 BAP, and 0.2 mg l-1 NAA. The shoots were then transferred to the root culture medium with the different hormonal treatments. The results showed that the best treatment to obtain the long and high roots was the ½ MS medium containing 0.25 mg l-1 NAA and 2 g l-1 activated charcoal. The seedlings obtained from the direct regeneration grew well after transplanting into the soil.

Orchis muscula L. is one of the worthwhile ornamental, medicinal, native and endangered species in Iran. In this research, plant tissue culture method has been used to propagate this valuable plant. For in vitro organogenesis, protocorm explants were surface sterilized and then cultured on different shoot and root induction media based on OrchiMax (OM) medium, supplemented with plant growth regulators with different concentrations alone or in combination. Based on results, the most shoot induction (100%) was obtained from protocorm explants cultured on medium containing 2 mg L-1 BAP and 0.5 mg L-1 NAA and the highest root induction (80%) was belonged to the treatment of IAA at 1 mgL-1.

This research was aimed to investgate the effect of light quality on micropropagation of pear rootstock OH×F333. First, single nodes explants were cultured in modified QL medium containing BA at four levels (0, 0.5, 1, and 2 mg/l-1) and IAA at three levels (0, 0.1, and 1 mg/l-1) and were evaluated for shoot proliferation. Then, plantlets subcultured in modified QL medium containing 1 mg/l-1 BA and were maintained in growth chamber under four level of light quality consisting red, blue and red-blue light provided by LED instrument and white cool light provided by florescent, all having 75 µmol m-2 s-1 intensity. For investigation of light quality on rooting, shoots were subcultured on modified QL medium containing 1 mg/l-1 IAA and were incubated under same light treatments. The results indicated that the highest number of proliferated shoots was obtained in red-blue light while the longest shoots and internodes was in red light treatment. Moreover, the number of leaves and nodes of plantlets grown under blue light were high. Light quality showed significant effect on rooting percentage, root number and root length. The highest rooting, with 100 percent rooting of shoots, was observed in red-blue light treatment. In contrary, the lowest percentage of rooting, the lowest number of root and the shortest length of root were observed in blue light treatment. Based on current results, combination of blue and red light in comparison to other light treatment was more appropriate treatment for shoot proliferation and rooting of pear rootstock OH×F333. The explants under this treatment showed higher number of shoots.

Carnation (Dianthus caryophyllus L.) is the third most important cut flowers in the world. Tissue culture techniques offer an efficient method for micropropagation of this ornamental plant. In present work effects of Kinetin (Kin) and Benzyl Adenine (BA), on shoot multiplication and hyperhydricity of four carnation cultivars (Prado Aquila Kgr, Skimo Mogr, Mondeo Kgr and Innove Orange Bogr) were studied. Explants from nodal segments were cultured on MS medium supplemented with different concentrations of BA (1, 2, 3 and 4 mg/l) and Kin (1, 2, 3 and 4 mg/l) in combination with 0.2 mg/l NAA, 30 g/l sucrose and 8 g/l agar. Rooting of regenerated shoots was done in the MS medium supplemented with 1 mg/l NAA. Results indicated that there is a significant difference among cultivars shoot regeneration, Eskimo and Prado Aquila Kgr with 3.2 and 1.5 shoots show the highest and lowest regeneration rate, respectively. Increasing the concentration of cytokinin from 1 mg/l to 4 mg/l lead to increase regenerated shoot number from 1.7 to 2.4 shoots per explant and increase hyperhydricity from 12% to 54%. In addition high concentration of cytokinin, especially BA, decreased height of regenerated shoots. Based on hyperhydricity percentage of regenerated shoots, there was a significant difference between cultivars and cytokinins. Mondeo Kgr and Prado Aquila Kgr showed highest (44%) and lowest (23%) hyperhydricity, respectively and explants cultured in medium supplemented with BA caused more (40%) hyperhydricity than Kin (26%). Results of present work showed that by increasing the concentration of cytokinin specially BA, multiplication will be increased but also it will increase the hyperhydricity of plantlets and consequently it will lead to death of them. By considering the amount of multiplication and frequency of hyperhydricity for obtaining the highest number of normal shoots, using of MS medium containing 1 mg/l BA in combination with 0.2 mg/l NAA is suggested.

St Johns Wort (Hypericum perforatum L.) from Hypericaceae is an important medicinal plant, which its secondary metabolites, hypericin and hyperforine, have several medicinal effects such as antidepressant, antiviral, antibacterial and etc. The importance of studying in vitro culture of medicinal plants is optimizing these protocols for subsequent studies about effective factors on biosynthesis of secondary metabolites and applying these methods in improving medicinal plants. Since now there are no report on in vitro culture of Iranian St Johns Wort and for the first time we studied the callogenesis, shoot regeneration and rooting process of this plant. The seeds of Iranian St Johns Wort were collected from Ardebil province and the base growth media was MS and for callogenesis we studied the effect of several levels of 2,4-D (0.25, 0.5, 1, 2 and 5 mg/l) and BA (0.25, 0.5, 1 mg/l) or KIN (0.25, 0.5, 1, 2 and 5 mg/l) and NAA (0.5, 1, 2 and 5 mg/l). Several levels of BA (0.25, 0.5, 1and 5 mg/l) and several levels of KIN (1, 2 and 5 mg/l) accompanied by 1 mg/l NAA were used for shoot regeneration in callus. Several levels of NAA (0, 0.5, 1, 2 and 5 mg/l) were used for rooting of the shoots. The growth condition was 25°c and 16/8 hours period for rooting and shoot regeneration, darkness for callogenesis. The results of callogenesis with Duncans Multiple Range Test at 5% showed that highest callus fresh weight (2.1937 gr) was obtained in 0.25 mg/l 2,4-D with 1 mg/l KIN. Results of shoot regeneration in level 5% showed that maximum number of shoots (95 shoots/call and 4 Cm length) obtained in treatment contain 1 mg/l NAA with 1 mg/l KIN. Results also showed that maximum root number (4.7 roots per shoot and 2.2 Cm length) was in hormone free media.