جستجوی مقالات مرتبط با کلیدواژه "direct shoot regeneration" در نشریات گروه "کشاورزی"

Petunia (Petunia hybrida) is an ornamental plant species of high economic potential. One of the appropriate methods for propagation and breeding of petunia is tissue culture. This experiment was conducted to investigate the effects of different concentrations of benzyl adenine (BA) either alone or in combination with different concentrations of naphthalene acetic acid (NAA) on the regeneration of adventitious shoots and callus production in Petunia hybrida. For the regeneration of adventitious shoots and callus production, leaf segment explants taken from germinated seeds were cultured on MS basal media supplemented with different concentrations of BA (0.1, 0.4, 0.8 mg L-1) solely and/or in combinations with and NAA (0, 0.1, 0.2 and 0.4 mg L-1). Cultures were incubated under dark conditions for two weeks and then transferred to light condition. After 20 days of keeping in the light condition, the results showed that BA and NAA had significant effect on shoot regeneration. When BA applied alone, the lowered concentrations were effective in shoot regeneration, however when used in combination with NAA, its increased concentrations were more suitable. The greatest percentage of shoot regeneration was recorded in the medium with high level of BA to NAA. The highest number and fresh weight of shoots (18 shoots per explant) were obtained in MS medium supplemented with 2 mg L-1 BA + 0.4 mg L-1 NAA. The greatest shoot length (5.1 cm) was obtained in MS medium containing 0.5 mg L-1 BA + 0.2 mg L-1 NAA. Also, the greatest callus fresh weight was observed in MS medium supplemented with 0.5 mg L-1 BA + 0.4 mg L-1 NAA. Therefore, MS medium supplemented with 2 mg L-1 BA combined with 0.4 mg L-1 NAA could be suggested for direct shoot regeneration and large scale propagation of petunia from leaf explants.

Plant tissue culture is a collection of techniques used to maintain or grow plant cells, tissues or organs under sterile conditions on a nutrient culture medium of known composition and widely used to produce clones of a plant in a method known as micropropagation. Plant research often involves growing new plants in a controlled environment. These may be plants that we have genetically altered in some way or may be plants of which we need many copies all exactly alike. These things can be accomplished through tissue culture of small tissue pieces from the plant of interest. These small pieces may come from a single mother plant or they may be the result of genetic transformation of single plant cells which are then encouraged to grow and to ultimately develop into a whole plant. Tissue culture techniques are often used for commercial production of plants as well as for plant research. Tobacco (Nicotiana tabacum L.) is one of the most important model plants used in the physiologic, genetic and tissue culture studies. The manipulation of tobacco genetic structure requires an efficient technique of gene transferring and regeneration. Whereas, the tobacco plant is a very effective bioreactor in the production of recombinant proteins, in this research we optimized the best tissue culture system and also, genetic transformation process of this plant.
Our plant tissue culture protocols, Include helpful information for Murashige and Skoog media, plant growth regulators, plant growth hormones, plant transformation systems, and other products for plant tissue culture. For this purpose, different concentrations of sucrose and 4 combinations of growth regulators (BAP and NAA) on callus induction, direct shoot regeneration and rooting were examined in a factorial experiment based on completely randomized design with 3 replications. The sensitivity of tobacco explants to kanamycin was examined through the cultivation of them on the selective medium with different concentrations of antibiotic. For genetic transformation, agrobacterium tumifacious (GV3101) harboring plasmid pBI121 was used and the transgenic plants were confirmed by PCR analysis.
The results of variance analysis and the means comparison showed that the best medium for callus induction was M1 (0.1 mg/l NAA and 1 mg/l BAP) with 15 g/l sucrose in the leaf explants, while the most direct shoot regeneration rate was obtained on the M1 medium with 30 g/l sucrose concentration. High-frequency of rooting was also influenced by 0/1 mg/l NAA and 60 g/l sucrose. So, supplementing the medium with NAA and BAP at different concentrations facilitated induction of multiple shoots from explants. NAA was proved to be the best and the number of shoots increased with increase in the concentration up to (0.1 mg/l), and exceeding this concentration resulted in decline in percent response as well as number of shoots was recorded shoot regeneration. The concentration of BAP was further increased a linear increase in the number of shoots was observed up to an optimal level (1 mg/l). Beyond the optimal concentration (1 mg/l), a decrease in the response as well as number of shoots was recorded due to profuse basal callusing. The effect of cytokinins on multiple shoot regeneration, higher concentrations of NAA found to be inhibitory for shoot regeneration because of huge callusing which hampered the growth and development of new shoots. Also different concentrations of sucrose have a different effect on the shoots and callus. The concentration of sucrose had significant effect on direct shoot regeneration. The main effect of sucrose concentration, concentration of 30 grams per liter, compared with a concentration of 15 grams per liter had the highest direct shoot regeneration. Concentration of 50 mg/l kanamycin could completely prevent the regeneration of untransformed explants so was used in the selective culture medium. Subsequently, the presence of nptII gene (798 bp) in the transgenic plants was confirmed and the transformation efficiency obtained by using the agrobacterium-mediated transformation was more than 95%.
Conclusions In present research, an efficient in vitro regeneration protocol has been developed for tobacco, where different factors including the age of the explant and plant growth regulators were optimized for maximum propagation of tobacco. The results showed that regeneration and transformation method described here is highly efficient and fast for the introduction of any foreign gene directly in tobacco plant.

Lepidium drabathrough the production of anti-cancer and anti-microbial compound, sulforaphane, is considered a valuable medicinal plants.Therefore, optimization of in vitro tissue culture to facilitate genetic transformation and improvement of traits in this plant is important. This study was conducted, by cotyledon, stem and root explants inMSmedium in the form of two separate tests. Data were analyzed in a factorial experiment based on completely randomized design. In the first experiment with different concentrations of growth regulators NAA and BAP, the highest response rate, direct shoot regeneration rate and direct shoot generation were related to root explants. The highest root production rate and root generation were showed in cotyledons explants. 1 mgl-1 BAP without NAA induced the highest direct shoot generation in root explants. Cotyledons explants in 2 mgl-1 NAA and 0.5 mgl-1 BAP produced the highest Root production rate and the highest root generation. Callus induction rate and callus initiation of stem explants were more than others, but the callus regeneration rate in three studied explants showed no significant difference. The highest shoot generation from regenerated callus was observed in the cotyledons explants. The second experiment with a combination of different concentrations of 2,4-D and BAP, under the influence of two treatments darkness and 16h photoperiod was performed. The highest investigated traits was in the 16h photoperiod. Cotyledons and stem explants were showed the highest callus induction rate and leaf explants showed the greatest weight of callus; While the highest callus regeneration rate and callus growth rate were obtained from the root explants.From leaf explants, the highest callus weightwas obtained from 0.5 mgl-1 2,4-D with 3 mgl-1BAP and the most growth rate of callus was obtained from 0.5 and 1 mgl-1 2,4-D and 3 mgl-1BAP. Also the combination of 2 mgl-1 2,4-D with 2 mgl-1 BAP and 3 mgl-1 BAP, produced the highest callus regeneration in root explants.