Medicinal Plants
Hoda Sajedimehr; Mahya Sajedimehr; Majid Azizi
Abstract
IntroductionMedicinal plants with a high level of antioxidant activity are of great importance due to their effect on a wide range of diseases such as diabetes, inflammatory diseases, Parkinson's, Alzheimer's, cardiovascular diseases, blood pressure and other diseases caused by oxidative stress. Therefore, ...
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IntroductionMedicinal plants with a high level of antioxidant activity are of great importance due to their effect on a wide range of diseases such as diabetes, inflammatory diseases, Parkinson's, Alzheimer's, cardiovascular diseases, blood pressure and other diseases caused by oxidative stress. Therefore, studying medicinal plants and extracting and identifying chemical properties and effective compounds in medicinal plants emphasizes the necessity of learning and using medicinal plants. Iranian shallot plant with the scientific name Allium hirtifolium is a species of the onion family (Alliaceae) and is one of the largest genera of the monocot group. Shallot plant is an important horticultural product that has been known and used as a vegetable, spice and medicinal plant since ancient times due to its useful properties. In this genus, there are economically important species such as: onions, garlic, shallots, chives and leeks. Germination and sprouting are one of the most important phenological stages (life cycle) of the plant. Having enough information about the phenological cycle of the plant leads to better management of the different stages of this cycle, which determines the degree of success of agricultural systems. Seedling germination and growth in the early stages are strongly influenced and controlled by environmental factors, especially temperature, soil moisture and seed quality (germination and seedling strength) and internal factors (growth regulators) such as Gibberellin and Abscisic acid hormones.In order to speed up the germination of seeds and eliminate seed dormancy so that germination can happen faster, there are different methods. One of these methods is mechanical or chemical scratching. The aim of this research is to present a precise and scientific description for the failure of Iranian shallot medicinal plant seed dormancy (Allium hirtifolium) and improvement in the acceleration of germination, considering the different characteristics in three populations of Iranian shallot seeds. Also, to increase the quality and accuracy in this research, a scanning electron microscope was also used to accurately determine the surface changes of the seeds before the acid-washing treatment with sulfuric acid and after the acid-washing treatment with sulfuric acid. In the previous research that has been carried out on Iranian shallot seeds, the simultaneous examination of different temperatures and different times of acid washing by sulfuric acid in a precise manner and with several populations that have different genotypes, as well as the use of Scanning Electron Microscopy (SEM) has not been done.Materials and methodsThe study was done to investigate the effect of different degrees of temperature, and different times of sulfuric acid for acid washing on the improvement of germination of three populations of Iranian shallot seeds (Allium hirtifolium). The effect of four different temperatures (5, 10, 15 and 20 degrees Celsius) inside the Germinator device and four different times of acid washing with sulfuric acid (0, 5, 10, 15 minutes) on germination and micromorphological characteristics of three populations of shallot plant (Feridon Shahr, Tiran and Khansar) was investigated. On the other hand, a scanning electron microscope (SEM) with different degrees of magnification was used for the effect of sulfuric acid treatment on the surface of the seed coat. The experiment was conducted as a factorial, in the form of a completely randomized design with four replications. At the end of the experiment, traits such as germination percentage, average germination time, germination speed, root length and shoot length were evaluated. Also, traits such as diameter, length, volume and weight of seeds in three populations of shallot were also analyzed statistically.Conclusion and discussionThe results of electron microscopy showed that in all three populations of Iranian shallot seeds, the seed coat, after using the acid washing treatment with sulfuric acid for 15 minutes, underwent noticeable and significant changes compared to the control seeds. The surface of the seed is destroyed by sulfuric acid and the surface of the seed does not have its natural ornamentation and protrusions compared to the control. Also, the effect of temperature, duration of acid washing and seed population on germination percentage, germination speed, average germination duration, seedling root length and seedling length was significant at the 1% probability level (p≤0.01). The population of Fereydoun Shahr has the highest germination percentage (69.16 percent), germination speed 3.7 (number of seeds per day) and average duration of germination 9.64 (number of seeds per day) at a temperature of 5 degrees Celsius and acid washing time of 15 minutes. The maximum shoot length and root length were 19.7 and 8.81 (mm) in the Tiran population with a temperature of 20 degrees Celsius and a 15-minute acid washing time, and in the Khansar population with a temperature of 20 degrees Celsius and time of 5 minutes acid washing respectively. The results show that, according to the dormancy of the seeds and their need for cold, the best temperature for shallot seed germination is 5 degrees Celsius with 15 minutes of acid washing by sulfuric acid. Diversity in shallot plant populations has a significant effect on the performance of this plant in improving seed germination.AcknowledgeWe thank Ferdowsi University of Mashhad and the Isfahan University of Technology.Keywords: shallot diversity (seed morphology), stratification, seed scarification, germination, scanning electron microscope (SEM)
Growing vegetables
Mahya Sajedimehr; Maryam Haghighi; Monireh Mehnatkesh
Abstract
Introduction
Drought stress is one of the most important factors limiting plant growth and production and leads to a reduction of more than 50% in the average production of most crops worldwide. Drought stress due to increased soil osmotic potential, especially in greenhouses where fertilizer consumption ...
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Introduction
Drought stress is one of the most important factors limiting plant growth and production and leads to a reduction of more than 50% in the average production of most crops worldwide. Drought stress due to increased soil osmotic potential, especially in greenhouses where fertilizer consumption is high, is one of the greenhouse crop problems.
Material and Methods
In the present study, two concentrations of polyethylene glycol at three levels of 0 (D1), -1.48 (D2), 4-91 (D3 ds/m to create different levels of drought stress due to osmotic changes in culture medium and application of KCl two levels (0 (K1) and 6 (K2) mmol / l) was used to reduce the possible effects. The experiment was performed as a factorial experiment in a completely randomized design with three replications. To apply drought stress, pot water was measured using a tensiometer, and when the drought reached below the field capacity (FC), irrigation with different concentrations of PEG and once a week spraying with KCl at the desired concentrations was done. Cucumber seeds were planted directly in 5 kg plastic pots containing a mixture of potting soil, including soil + sand + animal manure in the ratio of 1 + 2 + 0.5. The number of seedlings in each pot was 2 to 3 kg, which was reduced to one seedling seventeen days after sowing the seeds in the stage of three to four leaves. KCl spraying and spraying began in the three to the four-leaf stage of the seedlings and lasted for about a month. The plants were kept in the greenhouse during the experiment with an average temperature of 25 ° C and relative humidity of 70%. At the end of the experiment, dry weight, fresh weight, chlorophyll, chlorophyll fluorescence, flavonoids, carotenoids, proline, phenol, total protein, abscisic acid, superoxide, and ascorbate peroxidase, antioxidants, and catalase were measured.
Result
The results showed that the effect of foliar application of potassium in all traits except chlorophyll fluorescence and superoxide dismutase was significant (P <0.01). According to the obtained results, ccontrol treatment increased the amount of antioxidants and catalase, but the application of K2 on most of the measured parameters, including dry weight, fresh weight, chlorophyll, flavonoids, carotenoids, proline, phenol, total protein, abscisic acid, and superoxide disodium showed a positive effect. In D3 with the addition of K2 the highest amount of phenol and protein was observed. Also, the content of abscisic acid in all treatments increased with the addition of K2 and the highest amount was observed in D3 which can be concluded that the use of potassium at a concentration of 6 mM Acceptable cut. According to the results obtained in this study, it can be stated that the plant tries to maintain its osmotic pressure in the face of drought stress, and this is done by increasing osmolites such as proline and antioxidant enzymes that help maintain plant cell pressure and torsion. Potassium application can reduce the adverse effects of drought stress by improving the activity of antioxidant enzymes and preserving chlorophyll. Thus, the cell continues its vital activities and ultimately produces more acceptable performance under these conditions. In other words, increasing the antioxidant activity in drought conditions along with the application of potassium leads to a higher inhibitory capacity of reactive oxygen species and production stability in these conditions. Therefore, to compensate for at least some harmful effects of stress and help the plant to return to normal growth conditions after re-irrigation, foliar application of such elements can be effective in drought resistance of the plant and play a role. Based on the findings of this study, it seems that the application of potassium with a concentration of 6 mM is the most effective.
