Growing vegetables
Milad Cheraghi; Ali Asghar Hatamnia; Fardin Ghanbari
Abstract
Introduction Salinity is the most important environmental parameter limiting plant growth and productivity. The detrimental effects of high salinity on plants can be observed at the whole-plant level as the death of plants and/or decreases in productivity. Increasing salinity ...
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Introduction Salinity is the most important environmental parameter limiting plant growth and productivity. The detrimental effects of high salinity on plants can be observed at the whole-plant level as the death of plants and/or decreases in productivity. Increasing salinity is accompanied by significant reductions in number of leaves per plant, shoot weight, root weight, shoot length, and root length. With an increase in salinity, water potential and osmotic potential of plants become more negative. Two medicinal species of Coriandrum sativum L. and Anethum graveolens L. are herbaceous and annual plants of the Apiaceae family, which have many uses in the pharmaceutical and food industries. Considering the importance of these two medicinal species and the increase of environmental stresses including salinity stress in recent years, this research aims to investigate the effect of external application of melatonin on resistance to salinity stress in Coriandrum sativum L. and Anethum graveolens L. species and its effect on some morphological and physiological characteristics of these two species under salt stress. Materials and Methods This research was conducted in a factorial experimental format based on a randomized complete block design with three replications. Experimental treatments include five levels of salinity (0, 40, 80, 120 and 160 mM) and two levels of melatonin foliar spraying (0 and 100 μM). After the end of the treatment period, the morphological and physiological characteristics of the plant were measured by the different methods. Data analyses were performed using SPSS software version 20. Results were analyzed using one-way analysis of variance (ANOVA) followed by Tukey’s multiple comparison test. The results were expressed as mean values and standard error (SE) of the means. Results and Discussion The results of variance analysis indicated that species, melatonin and salinity stress have a significant effect on all morphological factors at the p < 0.05. The results of compare means showed that the number of leaves in both plants has a significant decrease at the probability level of 5% with the increase in salinity. However, the amount of this decrease in the samples that have been affected by melatonin is lower than the samples without melatonin. The use of melatonin has reduced the negative effects of salinity stress in two plants, so that at the salinity level of 160 mM sodium chloride, the use of melatonin has increased the fresh and dry weight of coriandrum sativum L. shoots by 7 and 3.61 times, respectively. The results of variance analysis showed that melatonin and salinity stress have a significant effect on all pigments. The results shown that with the increase in the level of salinity stress, a significant decrease (p < 0.05) was observed in the amount of chlorophyll and anthocyanin pigments of two species. The results of variance analysis showed that species and melatonin have a significant effect at the p < 0.01 on all physiological parameters, and salt stress has a significant effect at the p < 0.01 on all the physiological parameters except of relative water content. Also, the interaction effects of species with salinity, species with melatonin, melatonin with salinity and the interaction of all three factors have a significant effect at the 1% probability level on the parameters of proline and total phenol.With the increase in salinity, the amount of total protein in both species decreased, but the amount of this decrease was lower in the plants that were treated with melatonin. In coriandrum sativum L. plant, the amount of total protein reduction at 160 mM salinity level is 42.31% compared to the control, but this reduction was 28.9% in the plants that were treated with melatonin. Also, in the Anethum graveolens L., the amount of total protein reduction at the salinity level of 160 mM was 29.78% and 21.06% respectively, in the samples without melatonin treatment and under melatonin treatment. Conclusions The results of variance analysis of the data showed that melatonin has a significant effect at the probability level of 1 and 5% on all morphological and physiological parameters measured in both plants. Also, the compare means showed that with the increase in the level of salinity stress, a significant decrease in the probability level of 5% was observed in the parameters measured in two plants. In general, the external application of melatonin moderates the negative effects of salinity stress, and therefore melatonin can be used to improve the growth of plants under stress.
Growing vegetables
Zahra Darabi; Fardin Ghanbari; Javad Erfani moghadam
Abstract
Introduction
Low temperature is one of the most important environmental stresses that cause damage to plants and limit the geographical distribution of plant species. Plants of tropical and sub-tropical origin, such as cucumbers, are sensitive to cold stress and severely damaged at low temperatures. ...
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Introduction
Low temperature is one of the most important environmental stresses that cause damage to plants and limit the geographical distribution of plant species. Plants of tropical and sub-tropical origin, such as cucumbers, are sensitive to cold stress and severely damaged at low temperatures. Plants have evolved a set of defense mechanisms to adapt to low temperatures. These mechanisms include the regulation of gene expression and physiological and biochemical changes that increase plant resistance to chilling stress. Cinnamic acid (CA) is one of the most important phenolic acids present in all plants and has antimicrobial properties against fungi and bacteria. The application of this compound in some plants causes oxidative stress and leads to the activation of antioxidant enzymes. Therefore, in the present study, the effects of exogenous cinnamic acid treatment on cold stress tolerance in cucumber seedlings have been investigated.
Materials and Methods
This research was conducted in the greenhouse and laboratory of the Department of Horticultural Sciences of Ilam University in 2019. Cucumber seeds (Super Daminus cultivar) were planted in a 1: 1: 1 ratio of field soil, manure, and sand. In the fully developed two-leaf stage, seedlings produced were sprayed using cinnamic acid (at concentrations of 0, 50, 100, and 200 μM). Foliar spraying treatments were applied at the mentioned concentrations until the surface of the leaves was completely wet. 24 hours after foliar application, all plants were exposed to cold stress at 3 ° C for 6 hours in six consecutive days. After applying the cold treatment, the seedlings were transferred to the greenhouse and 72 hours later, the traits were measured.
Results and Discussion
The results showed that exogenous CA application increased the growth characteristics of cucumber seedlings subjected to chilling stress. Improving the growth and development of plants under stress conditions by cinnamic acid treatment has been reported in other studies, which is consistent with the results of the present study. It has been reported that cinnamic acid treatment, by causing oxidative shock in plants, leads to plant defensive responses to stress conditions, and through this, plants can better withstand stress conditions. These defense responses include increasing compatible solutions and improving the antioxidant system. In the present study, the use of cinnamic acid treatment increased proline, chlorophyll, and total phenol and reduced of membrane lipid peroxidation, and these changes led to a decrease in the apparent effects of cold on cucumber seedlings.
The use of chemicals that can mitigate the effects of cold on the plant can also help maintain plant growth under cold stress. In the present study, the application of cinnamic acid improved the growth of cucumber seedlings under cold stress conditions. Cinnamic acid pretreatment by inducing antioxidant compounds reduced the effects of cold on cucumber seedlings and improved plant growth in chilling conditions. Also, cinnamic acid treatment increased the growth of pepper plants under salinity stress, cucumber under drought stress, and wheat under drought conditions, which is consistent with the results of the present study. Therefore, it can be said that cinnamic acid improves plant growth under stress by changing physiological and biochemical processes. The results showed that the application of cinnamic acid improved the growth of cucumber seedlings under chilling stress conditions. Cinnamic acid pretreatment caused a significant increase in relative water content (25 to 32%), chlorophyll (108 to 125%), proline (152 to 244%), and total phenol (31%) compared to the control, therefore improving the adaptabilities of cucumber seedlings to chilling stress. The application of cinnamic acid also reduced the damage to cell membranes. The electrolyte leakage and malondialdehyde accumulation of cinnamic acid-treated seedlings were lower than that of control seedlings.
Conclusion
In general, the results of this study showed that the application of cinnamic acid reduced the effects of cold stress on cucumber seedlings. These results were associated with increased proline, chlorophyll, phenol and relative water content, in this way, the rate of ion leakage and accumulation of malondialdehyde in cucumber seedlings were reduced under cold stress. In general, the results showed that cinnamic acid treatment (especially concentration of 200 μM) can effectively reduce the effects of chilling on cucumber seedlings and improve their growth under cold stress.
Fardin Ghanbari; Saadollah Akbari
Abstract
Introduction: Melon, like other members of cucurbitaceae family, is sensitive to cold stress. Applying different cultivation techniques in the nursery can provide some degree of tolerance to environmental stresses in the plants. In the other words, applying stress conditions on plants may cause them ...
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Introduction: Melon, like other members of cucurbitaceae family, is sensitive to cold stress. Applying different cultivation techniques in the nursery can provide some degree of tolerance to environmental stresses in the plants. In the other words, applying stress conditions on plants may cause them to withstand subsequent stresses, this is so called a cross-adaptation or cross-tolerance. For example, Whitaker (1994) showed that cold stress damage can be mitigated by temperature pretreatment. This technique was then used to improve stress tolerance in different plants. In this regard, heat treatment has been used to increase the chilling tolerance in fruits and vegetables. Therefore, in this study, the possibility of increasing cold stress tolerance in melon seedlings using heat shock was investigated. Materials and Methods: The experiment was conducted in a completely randomized design (CRD) with three replications and five treatments (including control and spraying with water at temperatures of 20, 45, 50 and 55 °C for 90 seconds) in Faculty of Agriculture of Ilam University in 2019. Heat treatments where used as foliar spray by heated water. After applying different levels of heat treatment and recovery at 24 hours, seedlings were exposed to chilling stress at 3 °C for 6 h in 6 consecutive days. All seedlings were transferred to greenhouse and after 72 hours, the related traits were measured. Results and Discussion: Results showed that pre-treated seedlings had higher growth rate than control seedlings at the end of chilling period. Heat shock pretreatment significantly increased the content of chlorophyll, proline and hydrogen peroxide and reduced the amount of malondialdehyde compared to the control. The lowest amount of malondialdehyde (1.14 nmol g-1 fresh weight) was observed in the 50 °C treatment, which was 50% lower than the control. Similar to other environmental stresses, low temperature usually leads ROS production and oxidative stress. Malondialdehyde content is an index to measure membrane lipid peroxidation and its measurement is a criterion of damage to plants in stress conditions. Reduction of malondialdehyde has been reported to increase cell membrane stability and increase stress tolerance in plants. In the present study, heat shock reduced the accumulation of malondialdehyde compared to the control, indicating a decrease in cold effects on the plant. Mei and Song (2010) investigated the effect of heat pretreatment on increasing high temperature tolerance in barley, and reported that using this method by stimulating the synthesis of antioxidant enzymes prevented the increase of malondialdehyde in the plant under heat stress. Therefore, maintaining the membrane structure and decreasing the accumulation of malondialdehyde in melon seedlings under cold conditions indicates an improvement of plant defense responses induced by heat shock. Environmental stresses including cold stress by producing hydrogen peroxide and other free radicals lead to oxidative stress and damage plant cells. Hydrogen peroxide is converted to water by ascorbate peroxidase, peroxide redoxin, glutathione peroxidase and guaiacol peroxidase groups. Therefore, increasing the activity of antioxidant enzymes in plants is one of the most important mechanisms of the plant to cope with stress conditions. In the present study, heat shock pretreatment significantly increased peroxidase (POD) and poly phenol oxidase (PPO) activity and increased the amount of proline and hydrogen peroxide. In this regard, it has been reported that hydrogen peroxide has a dual role in plants and its increase in stress conditions by regulating the production of antioxidant enzymes helps plants to enhance their tolerance to the stress conditions. Our results is in consistent with Ao et al. (2013) report that stated hardening pretreatment of Jatropha curcas seedlings caused to increase the antioxidant enzymes activity, plant glutathione and ascorbate content. The increases in antioxidant enzymes activity by heat shock might be a positive mechanism, which facilitate the scavenging of ROS and induce plant growth and development under chilling stress. These results indicate that antioxidant defense system has a specific role in enhancing plant tolerance to stress conditions and hydrogen peroxide play an important signaling role in plant adaptive responses. Conclusion: In general, the results showed that heat shock (especially at 50 and 55 oC) caused positive physiological changes in melon seedlings and could increase their tolerance to cold stress conditions.
Fardin Ghanbari; Mohammad Sayyari
Abstract
Introduction: Due to its low level of calorie and being as an excellent source of C and A vitamins as well as containing lycopene as a powerful antioxidant, Tomato (solanum lycopersicum, 2n=2 x=24), is extensively consumed in the world. According to the statistics presented in 2013, following China, ...
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Introduction: Due to its low level of calorie and being as an excellent source of C and A vitamins as well as containing lycopene as a powerful antioxidant, Tomato (solanum lycopersicum, 2n=2 x=24), is extensively consumed in the world. According to the statistics presented in 2013, following China, United States, Turkey and Egypt, Iran ranked sixth in tomato production (6174182 kg per year) world tomato production. Similar to other tropical crops, tomato is sensitive to chilling stress. The chilling stress is considered as one of the environmental factors influencing growth and development of many plants including tomato. Applying different environmental conditions and cultivation techniques within transplant production can mitigate the chilling stress of seedlings. The seedling hardening is one of the simple technique being employed to physiological characters of plant, so as to induce subsequent stress resistance. This phenomenon is so-called cross tolerance and it means that exposing plants to stressful conditions can induce plant tolerance to upcoming stresses. Therefore, the objective of our study was to investigate the effect of drought hardening and chilling stress on tomato plant growth and productivity in field condition.
Materials and Methods: This experiment was conducted in greenhouse and research laboratories of agricultural college of Bu Ali Sina University. First of all, the seeds of tomato cv. C.H Falat, were sown in pots filled with perlite and vermiculite (ratio 2:1) and then maintained under natural light and at 25±2°C / 18±2°C (day/night). At four-leaf full development stage, seedlings were subjected to seven-day drought stress simulated with polyethylene glycol 6000 (PEG) at three levels: control (0% PEG), moderate drought stress (10 % PEG equaling to 0.18 Mpa osmotic potential) and severe drought stress (20% PEG equaling to 0.57 Mpa osmotic potential). After employing different levels of drought stress and consequently placing them in recovery for 48 h, they were exposed to chilling stress and non-chilling stress condition. For imposing chilling stress, the seedlings were transferred into growth chamber under 3°C for 6 days and 6 h per day. After receiving chilling stress treatments, the produced seedlings, were planted in the field.
Results and Discussion: In the present study, drought pretreatment reduced the effects of cold stress on fruit yield and quality. Results revealed that, the growth and yield of tomato plants were significantly increased by drought stress pretreatment in field condition. Herein, Seedlings without receiving drought pretreatment slowly grew and gained lower yield than those receiving drought. Some traits such as higher fruit size and shelf life and low number of decayed end blossom fruits were gained by drought application. The highest growth and yield rates were obtained through 10% PEG. These results indicate that drought stress at seedling stage increases the yield of tomato without harmful effects on fruit quality. The results showed that in 0% PEG treatment (control), chilling stress increased the number of days for flowering and fruiting, which indicates the growth retardation in this plant under cold stress condition. Drought pre-treatment using PEG increased the thickness of the pericarp and its post-harvest life, which may indicate the maintenance of the effects of initial stress in all stages of vegetative and reproductive growth. It has been reported that cold stress directly affects the growth potential of plants that interfere with the proper production of plants by disrupting metabolic reactions and indirectly by preventing the absorption of water by plants and oxidative stress (Hussain et al., 2018). In the present study, pre-treatment of drought reduced the destructive effects of chilling stress on fruit size. These results show that pre-treatment of drought (especially 10% PEG) had a significant effect on increasing fruit size and preventing its fruit yield reduction due to cold treatment. Similarly, Paradosi et al. (1987) reported that water stress in tomato plants increased its tolerance to cold and maintained the growth of tomato plants and its yield in cold greenhouse conditions. So far, there have been no reports of interactions between environmental stresses on fruit size, but the effects of drought stress on tomato fruit have been studied.
Conclusion: In general, the results of this experiment showed that the effects of drought pre-treatment on seedling remain in the next stages of tomato growth and can have beneficial effects on growth and yield of tomato in field conditions.
Rahmatollah Gholami; Ali Asghar Zeinanloo; Fardin Ghanbari
Abstract
Introduction: Germplasm and reservation of genetical resources is the principal of plant breeding. Different techniques have been used to characterize olive diversity. Morphological criteria such as leaf, fruit, seed and growth behavior have been used to evaluate olive diversity, to determine the origin ...
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Introduction: Germplasm and reservation of genetical resources is the principal of plant breeding. Different techniques have been used to characterize olive diversity. Morphological criteria such as leaf, fruit, seed and growth behavior have been used to evaluate olive diversity, to determine the origin of olive trees as well. An evaluation of phenotypic diversity was used to discriminate olive cultivars with distinct morphological and pomological characters. Iran is one of the origins of olive in the world and it has considerable variation across Iran. Recently olive cultivation and orchard development has been encouraged in Iran. In this developmental project of olive culture, it is necessary to provide agreeable genotypes for cultivation.
Materials and Methods: The present experiment was carried out to identify and evaluate local olive genotypes in Kermanshah province during 2004-2005. Those were located in six locations in Kermanshah province. Their morphological characters and oil content were investigated according to IOOC descriptor. Local genotype identification in this regions was based on morphological characters (Vegetative and reproductive) such as leaf, fruit, seed and growth behavior evaluated at four different growth phases, including onset of dormancy, flowering, fruit set and fruit growth in 39 local olive genotypes olive trees.
Results and Discussion: The results of this study showed that there was a great variation among genotypes in Kermanshah province. Those variations was observed within and between regions. Significant correlation was observed between the fruit weight, with leaf width, stone weight and percentage of flesh, also significant correlation were observed between oil percentage in fresh fruit weight, with internode length and leaf width. Factor analysis showed that five factors with eigen values greater than one, explains the 69.62 percent of diversity. Among these factors, two biggest factors justified a high degree of diversity and genotypes were better than the other factors that were superior in terms of oil content and fruit weight. Generally it can be concluded that genotypes of Kermanshah province wide variety and traits are also high correlated with fruit weight and oil content and can properly use these genotypes and traits in breeding programs. Olea europaea L. represents one of the most important trees in the Mediterranean basin and the oldest cultivated plant. Among cultivated plants, the olive is the sixth most important oil crop in the world, presently spreading from the Mediterranean region of origin to new production areas, due to the beneficial nutritional properties of olive oil and to its high economic value. The Mediterranean basin is the traditional area of olive cultivation and has 95% of the olive orchards of the world. From the Mediterranean basin, olive cultivation is presently expanding into other regions. wide range of distribution, it is becoming increasingly urgent to identify plants into different ranges of distribution in the world to avoid cases of homonymy, synonymy and mislabeling so that a reliable classification of all varieties can be achieved without unnecessary confusion. In this paper, along with morphological characteristics the acquisition of additional information on biochemical markers is essential. This aspect represents a fundamental and indispensable step to preserve the main olive varieties and also to safeguard minor genotypes, in order to avoid a loss of genetic diversity. This research has focused on using morphological markers to characterize and identify olive varieties. Identification of different varieties using morphological characters (vegetative and reproductive) is one of the aims of the modern horticulture, because such a technique would greatly facilitate breeding programs and germplasm collection management.
Conclusion: According to the results of this research, it can be concluded that there is a great variation among different genotypes. Variation was observed within and between regions. High correlation between the fruit weight and leaf width, stone weight and percentage of flesh was observed, also high correlation between oil percentage in fresh fruit weight, with internode length and leaf width were observed. Factor analysis showed that five factors with eigen values greater than one, explains the 69.62 percent of diversity. Among these factors, two biggest factors justified a high degree of diversity and genotypes were better than others of the factors that were superior in terms of oil content and fruit weight. Generally it can be concluded that olive genotypes of Kermanshah province can properly use in breeding programs
