Growing vegetables
Nasrin Farhadi; Mojgan Abdeshahian; Samane Mottagi
Abstract
Introduction
Currently, salinity stress is one of the most important challenges in the agriculture and is the main growth limiting factor of many plant species. Saline stress adversely affects the plant's physiological and biochemical process which leads to a considerable reduction of plant growth ...
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Introduction
Currently, salinity stress is one of the most important challenges in the agriculture and is the main growth limiting factor of many plant species. Saline stress adversely affects the plant's physiological and biochemical process which leads to a considerable reduction of plant growth and yield. Shallot (Allium hirtifolium Boiss.) is a perennial plant from the Alliaceae family, which is one of the native and valuable plants of Iran and wildly grows in the slopes of the Zagros Mountain range. The nutritional and medicinal value of shallots is due to the presence of sulfur compounds, especially allicin in the bulbs. The present study was conducted to investigating the effect of foliar application of salicylic acid on the changes of growth, physiological and biochemical traits of shallot under different levels of salinity stress in factorial design based on a completely randomized design with three replications. The investigated treatments were four levels of salinity (0, 30, 60 and 90 mM NaCl) and four levels of salicylic acid (0, 1, 1.5 and 2 mM). Distilled water (control) and salicylic acid (1, 1.5 and 2 mM) were foliar sprayed on the whole plants at 4, 6 and 8 weeks after sowing date. At the end of the growing season (beginning of yellowing of the leaves of the plants), growth, physiological and biochemical traits were evaluated. Evaluation of lipid peroxidation, osmolality compounds and activity of antioxidant enzymes was carried out in the leaves of treated plants and the amount of pyrovat and allicin was measured in harvested shallot bulbs.
Results and discussion
Various abiotic stresses restrict plant productivity, and many efforts have been done to reduce plant growth inhibition by alleviating the disorder’s effects of these stresses. Exogenous application of plant growth regulators has been reported as an economic procedure to improve plant resistance to environmental stresses. It has been previously reported that salicylic acid as a signaling molecule alleviated the adverse effect of different stress condition. In this experiment, shallot resistance to saline condition was enhanced by the foliar spray of salicylic acid. The results showed a significant link between salicylic acid treatment and improvement of bulb biomass under saline conditions. Lipid peroxidation regards to accumulation of malondialdehyde and hydrogen peroxide increased with increasing the salinity intensity. Also, saline stress significantly enhanced the proline and glycine betaine content in stressed plants of shallot. The plant antioxidant activity induced under stress condition by increased the total phenol content as well as the activity of catalase, peroxidase, ascorbate peroxidase and superoxide dismutase enzymes. The pyrovat and allicin content of shallot bulb was increased with increasing salinity stress. The decreased in the photosynthetic pigments (total chlorophyll and carotenoids) led to a decrease in plant growth with the intensifying of stress level. So that the lowest leaf area, fresh and dry weight of bulbs were obtained in severe salinity stressed plants (90 mM NaCl). Foliar application of salicylic acid through increasing the antioxidant compounds (total phenol, pyrovat and allicin) and the activity of antioxidant enzymes (CAT, POX, APX and SOD) limited the of hydrogen peroxide accumulation and lipid peroxidation. The induced accumulated osmolyte compounds proline and glycine betaine was decreased in treated plant with salicylic acid. The treatment of salicylic acid considerably improved the chlorophyll and carotenoids content especially in salinity stressed plants. So that the applied of salicylic acid, especially at concentration of 2 mM, reduced the harmful effects of salinity stress on plant growth and bulb yield by increasing the photosynthesis pigments and consequently photosynthesis efficiency. Also increased growth in the treated plants with salicylic acid has been attributed to changes in the concentration of plant hormones, especially auxins and cytokinins (the most important plant growth stimulating hormones). Nevertheless, the growth reactions of treated plants to salicylic acid are different depending on the used concentration, the plant species and the growth stage at the treatment time.
Conclusion
In the several literatures the salicylic acid effects on plant growth enhancement under unfavorable environmental condition attributed to salicylic acid-induced changes in plant biochemical and physiological processes. Based on the obtained results, the salinity resistance of the shallot plant in response to salicylic acid is related to the increased antioxidant capacity of the stressed plants, which leads to the improvement of the photosynthetic pigments, and consequently plant growth and bulb biomass under saline condition. Although the present study was performed in the glass greenhouse, the obtained finding showed that salicylic acid application could also be a promising treatment for improving salinity tolerance of A. hirtifolium under field conditions.
Nasrin Farhadi; Saeideh Alizadeh Salteh
Abstract
Introduction: Allium hirtifolium commonly known as Persian shallot is an important wild medicinal plant from Alliaceae family. Persian shallot commonly known as mooseer in Iran is a perennial diploid plant that is native to Iran and grows as a wild plant throughout in the Zagross Mountains range, western ...
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Introduction: Allium hirtifolium commonly known as Persian shallot is an important wild medicinal plant from Alliaceae family. Persian shallot commonly known as mooseer in Iran is a perennial diploid plant that is native to Iran and grows as a wild plant throughout in the Zagross Mountains range, western and southwestern Iran. It is a bulbous herb and usually consists of a single main bulb or rarely two bulbs. Each bulb has a weight of about 8-15 times of a garlic clove. The bulbs of mooseer has been widely used as a traditional herb and spice plant, added to a variety of foods such as salads, pickles, yogurt and different sauces. Conventionally, Persian shallot propagates through bulbs and seeds but these two methods are not commercially efficient due to low growth rate of bulbs and deep dormancy, low viability and germination rate of seeds. In addition, the natural habitat of this plant is under increasing pressure as a result of excessive incorrect harvest that caused to damage the plant density in Iran rangelands. So, improving the efficiency of A. hirtifolium propagation is necessary. A number of positive effects on the growth and productivity of some plants through cytokinin application have been registered by earlier research. The current study aimed to evaluate the effects of pretreatment and foliar application of forchlorfenuron as a safe cytokinin on improving the bulb production, phytochemical compounds and antioxidant attributes of Persian shallot.
Materials and Methods: This experiment was done at research green house of Tabriz University in 2015-2016. For pretreated of Persian shallot bulbs, they were soaked in 0, 50 and 10 mg l-1 forchlorfenuron solutions for 24 h. Then they were cultured in pots contained perlite and vermicompost with 3:1 ratio. Foliar application was applied 2, 4 and 6 weeks after culture with 0, 50, 100 and 150 mg l-1 concentrations of forchlorfenuron. At the end of growth season the number of leaves, number of bublets, fresh and dry weight of bulblet were recorded. The phytochemical compound (protein, phenol and allicin), antioxidant enzymes (catalase, peroxidase, ascorbate peroxidases and superoxide dismutase) and antioxidant activity of bulbs were assayed with spectrophotometry methods.
Results and Discussion: Foliar applications of plant growth regulators such as cytokinins in agriculture crops are reported to be useful in controlling multiple physiological processes, including flower initiation, shoot elongation, bulb production, fruit set and as well as affected the quality characters of products. In this study despite the bulblets number that did not influence by treatments, pretreatment and foliar application of forchlorfenuron significantly increased the leaves number, fresh and dry weight of bulbs in comparison with control plants. The highest leaves number (4.49 per plant) was obtained from pretreatments. The highest fresh weight (91.77 g) was recorded at 5 and 10 mg l-1 pretreatment and 100 mg l-1 (91.63 g) foliar application. The interaction effect of treatments on dry weight was significant and the highest dry weight (19.75 g) was recorded at 10 mg l-1 pretreatment with 100 and 150 mg l-1 foliar application. Allicin content did not show significant variation between treatments and in average was 0.859 mg g-1 FW. Total phenol content significantly influenced by treatments and the highest phenol content (1.585 mg GAE g-1 FW) was recorded at 5 mg l-1 pretreatment with 100 mg l-1 foliar application. The antioxidant enzymes included catalase, peroxidase and ascorbate peroxidase that showed significant increasing under forchlorfenuron treatments. Due to significant effects of forchlorfenuron on antioxidant compounds and enzymes of Persian shallot bulbs, the assay of antioxidant activity also showed a significant increasing in treated bulbs. The maximum percent of antioxidant activity (74.522) was obtained from 100 mg l-1 foliar application. Exogenous application of cytokinins plays an effective role by protecting the fluidity and integrity of plant cell membranes. They properly mediate enzymatic (SOD, APX, and CAT) and non-enzymatic machinery with the result of preventing cell membrane damage by oxidative stress.
Conclusions: Considerable improvement in biochemical and antioxidant attributes of Persian shallot was recorded with pretreatment and foliar application of forchlorfenuron. The present data support the potential uses of the forchlorfenuron for improving the production of weighty bulbs with the high antioxidants attributes in Allium hirtifolium. Pretreated and foliar application at 5 mg l-1 and 100 mg l-1 concentrations of forchlorfenuron, respectively showed the best results and is recommendable for A. hirtifolim production.
Nasrin Farhadi; Mohammad Kazem Souri; Abolfazl Alirezalu; Hossein Rabbi Angoorani
Abstract
Castor oil due to extraordinary physicochemical properties has numerous applications in pharmaceutical, chemical, hygienic, biodiesel and nowadays in food industries. During plant growth and development, as well as during postharvest and processing, different factors may affect caster oil properties. ...
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Castor oil due to extraordinary physicochemical properties has numerous applications in pharmaceutical, chemical, hygienic, biodiesel and nowadays in food industries. During plant growth and development, as well as during postharvest and processing, different factors may affect caster oil properties. This study was conducted to evaluate oil content and physiochemical properties under different sowing dates under climatic conditions of Tehran. The highest seed yield (1590.67 kg ha-1) and oil yield (774.43 kg ha-1) were obtained from 5th April Sowing date, that had significant difference with other sowing dates. In analyzed samples oil content were (%34.45-49/97), moisture content (%0.97-2.12), refractive index (1.470-1.473), chlorophyll content (0.26-0.40 mg Pheophytin/kg oil), acid value (0.28-0.62mg NaOH/g oil), peroxide value (0 meq O2/kg oil), soponification value (165.62-181.34 mg KOH/g oil) and iodine value (82.43-89.22 g I2/100 g oil). The results revealed significant differences for moisture and chlorophyll content, acid value (p
