A. Saffar Yazdi; A. Ganjeali; R. Farhoosh; M. Cheniany
Abstract
Introduction: Purslane (P. oleracea) is considered as valuable plant due to its high antioxidant compounds and important fatty acids such as omega-3 and 6. Phenolic and flavonoid compounds are one of the most important constituents in the purslane. Phenolics are a large group of natural plant compounds ...
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Introduction: Purslane (P. oleracea) is considered as valuable plant due to its high antioxidant compounds and important fatty acids such as omega-3 and 6. Phenolic and flavonoid compounds are one of the most important constituents in the purslane. Phenolics are a large group of natural plant compounds with antioxidant and Anti-inflammatory properties. Flavonoids, as a subset of phenolic compounds, have a wide range of effects on plants, including antioxidant activity and improve resistance to environmental stresses. Callus culture is one of the important strategies for the production secondary metabolites, which are difficult to produce chemically. Plant growth regulators including auxins and cytokinins play a crucial role in the stages of plant growth. Various combinations of these two hormones are used to make the desired changes in the cultures. Studies suggest that the accumulation of secondary metabolites can be increased by the application of different elicitors in medium. Researchers reported an increase in the content of secondary metabolites such as phenol and flavonoid compounds in calli treated with elicitors such as yeast extract. The purpose of this study was to determine the best explant, medium and hormonal treatment for calli induction of purslane. The effect of different levels of yeast extract on total phenol and flavonoid content and antioxidant capacity of purslane calluses was also investigated.
Materials and Methods: Seeds of purslane plant were cultivated in a solid 1/2MS medium for the preparation of sterile seedlings. The explants from sterile seedlings including to leaves, 1 cm stem specimens and terminal buds, were placed on MS and 1/2MS medium containing 0, 0.1, 0.3, and 0.5 mg L-1 BAP and NAA. After five months, calluses were evaluated for callogenesis and some morphological traits such as color, texture, and size, fresh and dry weight. This experiment was conducted based on completely randomized design with three replications. In the second experiment, the calluses obtained from the previous stage were transferred to MS medium with selected hormone treatment of the first experiment (0.5 mg L-1 NAA and BAP) and different levels of yeast extract (0, 125, 250, and 500 mg L-1). Total phenol and flavonoid contents of the calluses were determined by Folin-Ciocalteau and aluminum chloride methods, respectively. Furthermore, Ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used to determine the antioxidant activities.
Results and Discussion: The results showed that 1/2MS medium was suitable for sterile seedling production from purslane seeds. Based on the present study, only stem explants in a medium containing BAP and NAA, produced durable calluses. The color of the resulting calluses were green and had a constant and firm texture. The highest callus percentage (90.46%), the size (21.6 mm), and fresh (1826.5 mg) and dry weight (75.33 mg) of calluses belong to MS medium containing 0.5 mg L-1 BAP and NAA. Results of the second experiment showed positive and significant effects of yeast extract on the total phenol, flavonoid contents and antioxidant activities. The highest content of total phenol (664.12 mg GAE 100g-1 DW), flavonoid (42.25 mg QE 100g-1 DW) and FRAP data (787 µmol Fe g-1 DW) were obtained from the calli treated with 500 mg l-1 yeast extract. The maximum DPPH IC50 (2.45 mg ml-1) was also observed in control. The formation of callus associated with plant species, hormonal composition, the stage of development, and the type of explants. Auxin and cytokinin as plant growth regulators are key factors for controlling cell division in tissue culture. In most studies, callus formation in purslane plant were induced in medium containing auxin and cytokinin. The presence of green calluses derived from purslane explants can be due to the formation of chloroplastids in the cells of the callus tissue that rapidly produce chloroplasts under light conditions. In the second experiment, increased phenolic and flavonoid compounds with yeast extract treatment probably resulted in increased antioxidant activity.
Conclusion: In the present study, 1/2MS medium is suitable for the production of sterile seedlings from purslane seeds. MS medium containing 0.5 mg l-1 BAP and NAA is the best treatment for calli induction from stem specimens. The concentration of 500 mg L-1 of yeast extract is introduced as the most effective concentration for increasing the phenolic and flavonoid content and antioxidant activity in the purslane calluses.
Niaz Gholi Firozbakht; Mehdi Rezaei
Abstract
Introduction: Size of fruit in Japanese plum has an important role in marketability and fruit quality. In Golestan province, one of the most important areas of plum production in Iran, due to high temperatures in summer that led to unfavorable conditions in fruit ripening stage, final fruit size are ...
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Introduction: Size of fruit in Japanese plum has an important role in marketability and fruit quality. In Golestan province, one of the most important areas of plum production in Iran, due to high temperatures in summer that led to unfavorable conditions in fruit ripening stage, final fruit size are reduced in commercial scale. In this respect, the large financial loss is imposed to plum growers. Today, synthetic auxins are widely applied in the commercial gardens of the world in order to increasing fruit size and improving fruit growth . Auxins can promotes cell division, cell enlargement in fruit growth stages and it also acts as sink for nutrients absorption. In this study, the effects of the foliar application of two synthetic auxins were investigated on fruit qualitative and quantitative of Japanese plums in Golestan province climatic conditions.
Material and Methods: A split-plot factorial experiment based on randomized complete block design with four replications was conducted in a commercial orchard from Run Agri Company in Golestan province, Iran for two years (2015 and 2016). The main factor was considered four plum cultivars including ‘Ghatreh Tala’, ‘Shablon Zodras’, ‘Shablon Mianras’ and ‘Shablon Dirras’ which were spraying by two synthetic auxins: NAA (0, 300 and 400 mg/l) and 2, 4-D (0, 10 and 30 mg/l) along and in combination. Fruit length, diameter, length to diameter ratio and fruit weight, yield, yield efficiency and percentage of first and second fruit grade production characteristics were evaluated. Data analysis was performed by SAS 9.1 software and the comparison of mean values was done by Duncan's multiple range tests at 0.05 of probability level.
Results and Discussion: The results showed that foliar application of auxin significantly increased fruit size and weight. The results showed that the response of plum cultivars to synthetic auxins was different. Fruit length and width of ‘Shablon Dirras’ cultivar were increased with the 2,4-D application at 10 and 30 mg/l , but in the ‘Shablon Mianras’ cultivar, the combination of 2,4-D with NAA improved fruit size. NAA at its highest concentration (400 mg/l) plus 2, 4-D at its highest concentration (30 mg/l) produced the largest fruits and the highest yield in ‘Shablon Mianras’ cultivar. Stern et al. (16) also obtained similar results from NAA and 2, 4-D treatments in plum, which is confirmed our results. The yield (kg/tree) and yield efficiency in plum cultivars increased significantly by synthetic auxin treatments. The average of yield (kg/tree) by 2, 4-D and NAA foliar application increased 30, 60, 28 and 34 percent in ‘Shablon Zodras’, ‘Shablon Mianras’, ‘Shablon Dirras’ and ‘GhatrehTala’ cultivars, respectively. The highest yield efficiency was obtained in ‘Shablon Mianras’ cultivar (0.38 kg/cm2) in 30 mg/L of 2, 4-D plus 400mg/L of NAA, which showed a 120 % increasing in comparison to control trees. Denis (7) reported increases the quantitative characteristics of stone fruits such as fruit size and weight by using synthetic auxin spray. The effect of auxin on increase cell proliferation and cell size are main reason for increasing the length and weight of the fruits (7). The results showed that 2, 4-D and NAA auxins were able to increase the percentage of first grade fruit relative in all plum cultivars in comparison to the control trees, but the concentrations and composition of plant growth regulators that increased the percentage of first grad fruits were not completely same to best treatments on fruit size, weight or yield. It referred to the first-grade fruits selection criteria. In selecting of best marketable fruits, in addition to the size of the fruit, others feature such as fruit appearance, color, physical damage and the absence of symptoms of diseases are also taken into grading. Temperature, water, nutritional and genetic conditions can affect the effect of plant growth regulator treatments (13).
Conclusions: Plum cultivars showed different reactions to synthetic auxin treatments. The largest fruit, highest yield and yield efficiency obtained in 2,4-D (30 mg/l ) with NAA (400 mg/l) in ‘Shablon Mianras’, ‘Shablon Dirras’ and ‘Ghatreh Tala’ cultivars and 2,4-D at 30 mg/l with NAA at 300 mg/l concentration in ‘Shablon Dirras’ and ‘Ghatreh Tala’ Cultivars. The highest degree of first grad-fruit was observed at 10 mg/l 2,4-D in ‘Shablon Zodras’ and ‘Dirrras’ cultivars and 300 mg/l of NAA in ‘Shabolon Mianras’ and ‘Ghatreh Tala’ cultivars.
H. Hadizadeh; M. Mohebodini; B. Esmaeilpoor; E. Chamani
Abstract
Introduction: Chicory (Cichorium intybus L.) belongs to Asteraceae family is commonly known as witloof chicory. The leaves and the roots of this medicinal plant are edible and commonly used as salad. Some varieties are also cultivated as coffee substitute after roasting the roots. All parts of the plant ...
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Introduction: Chicory (Cichorium intybus L.) belongs to Asteraceae family is commonly known as witloof chicory. The leaves and the roots of this medicinal plant are edible and commonly used as salad. Some varieties are also cultivated as coffee substitute after roasting the roots. All parts of the plant contain these volatile oils, with the majority of the toxic components concentrated in the plant's root. In folk medicine, the plant is used for the treatment of diarrhea, spleen enlargement, fever, and vomiting. Antihepatotoxic activity on damaged rat’s liver sections and anti-bacterial activity of this crop has been recently reported. In vitro regeneration from leaf explants with various hormonal combinations has been reported previously. Moreover, in vitro regeneration of Chicory from cotyledon explants using different combinations of plant growth regulators has been studied. Also, a protocol for the regeneration of plantlets from leaf and petiole explants of witloof chicory has been developed. The aim of the present investigation was optimization of callus induction and shoot regeneration from leaf and petiole tissues of Chicory (Esfahan genotype).
Materials and Methods: In this investigation, Esfahan genotype was used for callus induction and direct shoot regeneration. Seeds were first washed with running tap water for 30 min then seeds were surface sterilized by dipping in 70% ethanol for 90 s and rinsed with sterile distilled water, followed by immersing in 5% sodium hypochlorite solution for 25 min and thereafter rinsed for 30 min with sterile distilled water. The basal medium used in this investigation was MS. For shoot regeneration, leaf and petiole explants (5 mm segments) were excised from 4-week-old sterile seedlings and cultured on MS medium containing different combinations of NAA / BA and KIN / BA in two separate experiments. Experiments were performed factorial based on completely randomized design. Cultures were incubated at 25° C ± 2 with a 16/8 hour (day/night) photoperiod and an irradiance of 1500 LUX using Sylvania cool white fluorescent tubes. The percentage of callus induction, shoot regeneration and the number of regenerated shoots were calculated for the leaf and petiole explants. Data was subjected for analysis of variance and means were compared in 5% level with Duncan’s multiple range tests.
Results and Discussion: Explants cultured on medium containing either no plant growth regulators (control) or cytokines alone produced no callus. However, after 2 weeks, other concentrations of NAA and BA indicated callus formation from leaf and petiole explants in all hormone combinations. In leaf explants, the highest callus induction were obtained in the medium containing 0.3 mg l-1 NAA with 1 mg l-1 KIN and 0.3 mg l-1 NAA with 1.5 mg l-1 KIN (81.25%). Leaf and petiole explants cultured on medium containing no plant growth regulators (control treatment) and medium containing NAA produced no shoots. The combination of 0.3 mg l-1 NAA and 0.1 mg l-1 BA was the best treatment tested. This treatment produced 2.7 shoots per explant at 71% shoot regeneration frequency in leaf explant and 2.73 shoots per explant at 73% shoot regeneration frequency in petiole explants. The results also showed that the highest percentage of regeneration and the highest number of regenerated shoots were obtained in the medium containing 0.1 mg l-1 NAA and 1 mg l-1 KIN in leaf explants (65.6% regeneration and 1.37 shoots per explant, respectively). The highest number of regenerated shoots was obtained in the medium containing 0.3 mg l-1 NAA and 0.5 mg l-1 KIN in petiole explants (40.6% regeneration and 0.5 shoot per explants, respectively. Shoot regeneration requires plant cells to undergo dedifferentiation which is known to be affected by not only exogenous plant growth regulators but also endogenous content of the hormones. Different tissues may have different levels of endogenous hormones and, therefore, the type of explant source would have a critical impact on the regeneration success. In our study, when leaf and petiole explants were compared, it was clear that leaf explants were much more productive for regeneration than petiole explants.
Conclusion: Callus induction and shoot regeneration are in vitro tissue culture methods. Plant growth regulators and types of explant are the most important factors for callus induction and shoot regeneration phases. Therefore, optimization of these factors is essential to establish a high frequency of callus induction, shoot regeneration and gene transfer to this plant.
