Pomology
Masud Fattahi; Abdolrahman Mohammadkhani
Abstract
Introduction
UCB-1 hybrid rootstock is propagated from the seed of a controlled cross between a P. atlantica female and a P. integerrima male. Clonal propagation of this rootstock is also necessary since it produces identical genotypes. UCB1 has recently been introduced in Iran. However, little ...
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Introduction
UCB-1 hybrid rootstock is propagated from the seed of a controlled cross between a P. atlantica female and a P. integerrima male. Clonal propagation of this rootstock is also necessary since it produces identical genotypes. UCB1 has recently been introduced in Iran. However, little research has been done on this subject. Water stress is one of the most important environmental stresses and occurs for several reasons, including low rainfall, high and low temperatures, salinity, and high intensity of light, among others. Drought stress is a multidimensional stress and causes changes in the physiological, morphological, biochemical, and molecular traits in plants. Proline is also found widely in plants and accumulates in large quantities in response to environmental stresses such as drought. It is the essential amino acids that accumulate in different tissues of the plant, especially in the leaves through the effect of water stress, and that the accumulation of it has a function in the regulation of osmosis in the cell as the proline is increased in the cytoplasm to counterbalance effort osmosis cell sap. Proline is an indicator of water stress tolerance and its increase in the leaf proof that the plant suffered drought stress, also is the way the plant tolerance to drought stress.
Materials and Methods
A pot experiment was conducted, to investigate the effectiveness of foliar applied proline in mitigating the concurrent effects of drought stresses on UCB1 rootstock, at greenhouse of Faculty of Agriculture, University of Shahrekord. Experiment was carried out in a completely randomized design with split arrangement having three replications. Chl. and carotenoid contents were determined according to Lichtenthaler (1987). Leaf discs were obtained from expanded leaves of each pot in the morning. The leaf discs were weighed immediately to obtain the fresh weight (FW), and submerged in distilled water for 4 h at 4◦C in dark condition and then weighed to prepare turgor weight (TW). The leaves were dried in a forced-air oven at 70◦C for 24 h, and the dry weight (DW) was recorded. The RWC of samples was calculated using the following equation (Bastam et al., 2012): RWC = [(FW–DW)/(TW–DW)] × 100
Levels of glycine betaine were quantified as described previously by Arakawa et al. (1990). To determine the free-proline concentration, leaves were homogenized in 5 ml of ethanol at 95%. Proline concentration was calculated with a standard curve and expressed as µg g−1fresh mass (Paquin and Lechasseur, 1979).
Results and Discussion
The UCB1 proximate analysis in the present study depicted that imposition of drought stress increased the leaf and root proline content and electrolyte leakage. Exogenous application of proline as foliar spray significantly increased the moisture content of leaf and root, RWC, Chl a and total chlorophyll. Exogenous proline application upregulated leaf and root proline contents and decreased the lipid peroxidation (decrease electrolyte leakage), resulting into improvement in chlorophyll contents. 150 mg. l-1 proline application gave maximum alleviation against stress.
Numerous reports depict that the exogenous application of proline as a foliar spray can play an important role in enhancing plant tolerance against drought stress, and our results are consistent with them. This ameliorating effect of exogenously applied proline can take the form of osmoprotection, cryoprotection, or protection against reactive oxygen species.For example, in various plant species growing under stress conditions, exogenously supplied proline provided osmoprotection and facilitated plant growth. Normally, proline accumulation in plants, is in response to drought or salinity stress occurs in the cytosol where it contributes substantially to the cytoplasmic osmotic adjustment. It actively takes part in plant osmotic adjustment under stressful environmental conditions. In addition to its role as an osmolyte for osmotic adjustment, it actively takes part to stabilize subcellular structures, biological membranes, proteins, and scavenge free radicals. It also plays a vital role in buffering cellular redox potential under stressful environmental conditions.
Conclusion
In summary, our results showed that, drought induces a decrease in moisture content, RWC, T Chl and carotenoids and an increase in some osmoregulators (proline, glycine betaine, TSC). The most favorable treatment was 150 mg.l-1 proline foliar spray. 150 mg.l-1 proline application gave maximum alleviation against stress. Foliar application increased the moisture content of leaf and root, as well as increased the Chl a, total, RWC and proline content of leaf and root. It can be suggested that the foliar application of proline (150 mg L-1) used as a plants defense factor against drought stress conditions.
Medicinal Plants
Rahele Ghanbari Moheb Seraj; Mehdi Behnamian; Asadollah Ahmadikhah; Vahid Shariati; Sara Dezhestan
Abstract
Introduction
Plant growth and yield are affected often by stress conditions, especially drought, which is the most important factor in reducing crop production worldwide. Silybum marianum is an important pharmaceutical crop with great potential as a multipurpose plant for low-input cropping systems ...
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Introduction
Plant growth and yield are affected often by stress conditions, especially drought, which is the most important factor in reducing crop production worldwide. Silybum marianum is an important pharmaceutical crop with great potential as a multipurpose plant for low-input cropping systems of the arid and semiarid regions.
Materials and Methods
In this experiment, the effect of drought stress (full irrigation at field capacity; no stress, irrigation at 70% of field capacity; mild stress and irrigation at 40% of field capacity; severe stress) on physiologic traits, the amount of silybin a and b and 1000 seed weight in milk thistle was studied in the research field of Shahid Beheshti University in 2017-2018. The experimental site is located in Shahid Beheshti University, Tehran, Iran (51.23°N, 35.48°E, and 1769 m above mean sea level). It has a moderate and mountainous climate with a mean annual rainfall of 145.2 mm and a mean temperature of 22ºC. This experiment was performed in a completely randomized block design with 3 replications. Milk thistle seeds were prepared from Isfahan Pakanbazr Company. The soil composition consisted of 1/3 clay, 1/3 sand, and 1/3 leaf composts. The field area was 150.0 m2. Furrows were created to implement this study. The space of plants on rows was 0.5 m and between rows was 1 m. In general, 15 furrows were created and 15 plants were cultured on each furrow, so the total number of plants cultivated on the field was 225. Drought stress was applied at flowering stage. Soil moisture was measured by the weighing method. The soil samples were taken from various areas (randomly) of the field, three samples each day. After measuring the water content at F.C, based on that, the amount of 70%F.C and 40%F.C was also calculated. At the time of stress, F.C irrigation was performed every two days, 70% F.C irrigation every 4 days, and 40% F.C irrigation every 6 days. After 8 days, leaf sampling was performed to measure catalase, ascorbate peroxidase, proline and malondialdehyde content and seed sampling was performed to 1000 seed weight and extract analysis. For physiologic measurements, 3 plants were randomly assigned to each stack and their leaves were separated and transferred to the laboratory. Then, in the next step, their physiologic parameters (include Catalase and ascorbate peroxidase, proline and malondialdehyde content) were measured according to the relevant protocol. In order to measure silybin, 4 plants were randomly considered to each stack and their seeds were harvested and combined and dried in shade condition in the laboratory for one month. The dried seed samples were completely powdered using a mill, then 10 g of the powders weighed and the oil extract of them was isolated by Soxhlet using n-hexane solvent. The extraction temperature was 70 °C and the extraction time was 6 h. After the extraction was completed, the extract was poured into dark glass. Next, the oil-free powder was dried in an incubator at 37 ° C. Methanol extract of oil-free powder was extracted using methanol solvent. For this purpose, 2 g of samples powder was weighed and 200 ml of 80% methanol was added to each of them and the mixture stirred for two days by Shaker. The mixture was then passed from a filter paper and after that, 200 ml of 80% methanol was added to the sample precipitate (on filter paper) and placed again on the shaker. After 24 h, extraction was performed by the same method and were added to the previous extract. The extracts were then concentrated in the environment temperature for two weeks. Concentrated extracts (powder) as well as standard silymarin with certain concentrations were dissolved in methanol solvent and used for injection into HPLC (Model: Infinity1260, Manufacturer: Agilent) using syringe filters with a diameter of 0.2 μm. After receiving the HPLC results, the data and peaks were analyzed and the amounts of silybin a and b were determined and compared at different levels of water stress. Statistical analysis of data was performed using R 3.6.1 and RStudio 1.1.463 software. Mean data were compared using Duncan's test with agricolae package at a significance level of 0.05.
Results and Discussion
The results showed that with increasing water stress intensity, the amount of silybin a and silybin b increased by 24% and 26%, respectively. The amount of these compounds in 40% were significantly higher than other treatments, so that its amount compared to F.C treatment (26.07 mg/g Grain DW in silybin a and 40.74 mg/g Grain DW in silybin b) and compared to the 70%F.C (25.32 mg/g Grain DW in silybin a and 34.64 mg/g Grain DW in silybin b) was higher. This indicates carbon assimilation from photosynthesis to produce secondary metabolites in this treatment. Also, the amount of silybin b compared to silybin a in all treatments was (0.8: 1.2), in which 1.2 is related to silybin b and 0.8 is related to silybin a. In severe stress treatment (40% of field capacity), the amount of silybin a and b (67.30 and 98.92 mg/g, respectively) increased significantly compared to other treatments. According to the mean comparison results, the highest activity of catalase (5.16 U/ml) and ascorbate peroxidase (2.26 U/ml) was observed in mild stress treatment. Proline content gradually increased with increasing stress intensity and reached its peak in severe stress (3.36 µM/gr). Lipid peroxidation also had their maximum in severe stress (8.35 nmol/grFW). The 1000 seeds weight was reduced by 6.8 g in severe stress treatment (40%F.C) compared to the control (F.C).
Conclusion
According to the results, the amount of milk thistle flavonoids can be increased for medicinal purposes including the treatment of liver disease and hepatitis by applying dehydration stress.
Mohammad Sadat Farizani; Hamid Reza Khazaee; Ali Gazanchian
Abstract
Introduction: Beautification of urban space and creating attractive face for cities by development of green space has caused to capita of urban green space be introduced as an important factor in urban development. Meanwhile, the important role of cover plants, especially turf grass, in creating green ...
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Introduction: Beautification of urban space and creating attractive face for cities by development of green space has caused to capita of urban green space be introduced as an important factor in urban development. Meanwhile, the important role of cover plants, especially turf grass, in creating green spaces has caused to add quickly the area of these beautiful plants in the cities. Nevertheless, existence of plants with high water requirements between the turf grasses, have created limitations in terms of water requirements supply. The grass planted in the country is mainly from imported seed types that are not so compatible with dry and semi-arid conditions in our country and from this point of view, sometimes they create limitations in terms of water supply. One of the native grasses in the country, is Tall Fescue (Festuca arundinaceous), which is a variety of cool-season, perennial and herbaceous grasses. One of the strategies to preserve grass under drought stress is improving soil structure with the aim of increasing the moisture. Organic compounds that improve soil physical and biological conditions (such as municipal waste compost and manure) can be effective. Using compost improves soil structure and strengthens soil mineral content and allows soil to retain moisture for longer. Because compost can hold water about two to six times its volume and prevent it from being wasted. Compost in heavy soils, improves soil porosity and makes the soil better ventilation elderly. In light soils, it acts like a sponge and by keeping water and food safe, it will greatly prevent them from being washed. Therefore, present research was done to evaluate the effect of mixing different amounts of Municipal Solid Waste (MSW) compost with soil on some physiological properties of Tall Fescue native grass under moisture stress conditions.
Materials and Methods: This research was conducted in the form of two experiments in research greenhouse of Ferdowsi University of Mashhad. The first experiment with aim of evaluating percentage and rate of grass emergence was conducted in a completely randomized design with four replications that the experimental treatments consisted of ten different levels of compost mixing with soil (10 up to 100 t.ha-1) and control treatment (agronomic soil without mixing compost). In the second experiment, three values of 70, 80 and 90 tons of compost per hectare plus control (no compost consumption) as the first factor and three levels of moisture stress of 25, 50 and 100 percent of field capacity as intense stress, mild stress and without stress, respectively as the second factor that were compared in factorial by a completely randomized design with four replications.
Results and Discussion: The results of the first experiment showed that the amounts of 70, 80 and 90 tons per hectare increased significantly the percentage and rate of grass emergence due to increased fertility and higher water holding capacity and in these treatments, the positive effect of rising water holding capacity has been dominated on negative effect of electrical conductivity of the soil and this topic has led to an improvement in the percentage of grass emergence in these treatments. Furthermore, in the amounts of 70, 80 and 90 tons of compost per hectare, the bulk density of soil significantly decreased and the C/N ratio dramatically increased. In the second experiment, with increasing drought stress in different amounts of compost, the total chlorophyll content decreased and relative water content of plant, proline and electrolyte leakage increased. In the compost treatment of 90 tons per hectare, due to its high ability to store water, the cell membrane integrity was more preserved and it was done less understanding of stress. The shoot dry weight decreased significantly as a result of increasing the severity of drought stress.
Conclusion: Based on the findings of this study, application of 90 tons of compost per hectare significantly improved some of physiological traits for Tall Fescue grass in drought stress conditions. Also, it seems that Tall Fescue grass cleverly has tried to deal with drought stress with target of increase the amount of moisture available for itself. Therefore, using 90 tons of compost per hectare for Tall Fescue grass in low water conditions and occurrence of moisture stresses is recommended.
Mohammad Hossein Sheikh Mohammadi; Nematollah Etemadi; Ali Nikbakht; Mostafa Arab; Mohammad Mehdi Majidi
Abstract
Introduction: Drought and salinity are the most detrimental abiotic stresses for turfgrass growth across a wide range of geographic locations. Most cool season grass species are not well adapted to extended periods of drought and salinity stress. The decline in turf quality caused by drought and salinity ...
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Introduction: Drought and salinity are the most detrimental abiotic stresses for turfgrass growth across a wide range of geographic locations. Most cool season grass species are not well adapted to extended periods of drought and salinity stress. The decline in turf quality caused by drought and salinity stresses is a major concern in turfgrass cultivation and management. Therefore, developing management practices for improving drought and salinity resistance of turfgrasses has become imperative in arid and semiarid regions. Grass genotypes differ in their responses to drought and salinity stresses, which involve changes in morphological and physiological aspects. Understanding of relative involvement of each morphological and physiological characteristic in drought and salinity tolerance is important in selecting grass genotypes to facilitate breeding of drought and salinity-tolerant genotypes. The purposes of this research were to make selections of genotypes tolerant to drought and salinity stress for turfgrass management program.
Materials and Methods: To study some morphological and physiological responses of six Iranian crested wheatgrasses (Agropyron cristatum L.) under drought and salinity, an experiment was conducted in the greenhouse of College of Abureyhan, University of Tehran, Iran. Six Iranian Agropyron cristatum genotypes were collected from six locations in Iran. Agropyron cristatum genotypes were planted in polyvinyl chloride tubes and kept in the greenhouse. Pots were filled with sandy loam soil which had been sterilized in an oven at 160ºC for 6 h. Irrigation was applied as needed to prevent any visible stress during grass establishment. Grasses were watered three times weekly to maintain plants under well-watered conditions and soil moisture at field capacity. The experiment consisted of three treatments: 1) well-watered plants were irrigated three times per week with distilled water (control), 2) Drought stress was imposed by withholding irrigation for 45 days (drought stress), and 3) plants were irrigated daily with 100 mL of 9 dS.m–1 NaCl solution (salinity stress). To avoid primary salinity shock, the soil in each pot was drenched with 100 mL NaCl solution at incremental electrical conductivity (EC) by 3 dS.m–1 per day until the final EC reached 9 dS.m–1. Data were subjected to analysis based on a split-plot design with water treatments as main-plots and genotypes as sub-plots. Irrigation treatment as the main factor in three levels (control, drought, and salinity) and crested wheatgrass at six levels were considered as sub-plots. Studied characteristics such as height, turf quality, chlorophyll content, soluble carbohydrates, relative water content, electrolyte leakage, root penetration, and effective root depth were recorded. Statistical significance was tested using the analysis of variance procedure in SAS 9.1 (SAS Institute Inc., Cary, NC). Differences between the means were determined using the Fisher’s protected LSD test at the 5% probability level.
Results and Discussion: The results of this study showed that drought and salinity stress decreased the quality of crested wheatgrass masses, and reduced the level of quality varied among the masses. Throughout the experiment, ‘Sabzevar’ and ‘Damavand’ under drought conditions and ‘Sabzevar’, ‘Arak’ and ‘Damavand’ under salinity conditions maintained higher Turf quality compared with other genotypes. Total chlorophyll content of ‘Sabzevar’ and ‘Damavand’ were higher than other genotypes under drought and salinity conditions. The maintenance of higher chlorophyll content has been associated with better drought and salinity tolerance in plant. The soluble sugar content of ‘Sabzevar’ and ‘Damavand’ under drought conditions and ‘Sabzevar’, ‘Arak’ and ‘Damavand’ under salinity conditions were higher than other genotypes during the experiment. Soluble sugar content is an important compatible osmolyte in plants. Increased accumulation of soluble sugar content in stressed plants may be an adaptation process and resistance strategy to abiotic stresses in plants. Throughout the experiment, ‘AEKQI’, ‘Sabzevar’ and ‘Damavand’ genotypes under drought conditions and ‘Sabzevar’ genotypes under salinity conditions maintained higher relative water content in compared with other genotypes. Higher RWC indicates the ability of the leaf to maintain its higher water content under stress conditions with the simultaneous capability of the root system to take up adequate water. Based on morphological and physiological analysis for drought and salinity tolerance in investigated genotypes, the tolerance ranking would appear to be ‘Sabzevar’ > ‘Damavand’ > ‘Arak’ > ‘Urmia’ = Takestan > ‘Hashtgerd’ under drought stress and ‘Sabzevar’> ‘Arak’ > ‘Damavand’ > ‘Takestan’ = ‘Hashtgerd’> ‘Urmia’ under salinity stress. The results of this study showed that ‘Sabzevar’ and ‘Damavand’ genotypes had good tolerance to drought stress, and ‘Sabzevar’ and ‘Arak’ genotypes had good tolerance to salt stress than other Iranian crested wheatgrass genotypes.
Masud Fattahi; Abdorahman Mohammadkhani
Abstract
Introduction: Abiotic stresses, in particular drought, not only compromise crop quality and limit yield, but also restrict the geographical range over which crop production is viable. Plant species have evolved a number of physiological and molecular means to cope with adverse environmental conditions. ...
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Introduction: Abiotic stresses, in particular drought, not only compromise crop quality and limit yield, but also restrict the geographical range over which crop production is viable. Plant species have evolved a number of physiological and molecular means to cope with adverse environmental conditions. Grapevine is a perennial crop grown in various areas around the world. It is highly responsive to local environmental conditions and viticultural practices. Abiotic stresses cause extensive losses to agricultural productivity. Grapevine is no exception to the rule and faces several abiotic stresses throughout its lifespan. Drought, salinity, or heavy metals are serious problems in many parts of the world. The potential of AMF to enhance plant tolerance to abiotic stress conditions has long been known, and their use in sustainable agricultural systems will be of tremendous importance for soil quality and crop productivity under severe edapho-climatic conditions. Arbuscular mycorrhizal fungi (AMF), a kind of beneficial soil microorganism, can create a symbiotic association with plant roots forming arbuscular mycorrhizas (AMs), which play a role in the regulation of plant growth. This research was carried out in order to determine the effect of deficit irrigation on morphological characteristics of grapevine ʽAsgariʼ cultivar in greenhouse conditions in 2016.
Materials and Methods: The layout was as a factorial experiment in a completely randomized design with three replication and two factors, including Arbuscular mycorrhizal and irrigation regimes. Irrigation treatments were irrigation with 100% moisture content of field capacity (control), 70% moisture content between field capacity and permanent wilting point (MAD 30) and 40% moisture content between field capacity and permanent wilting point (MAD 60) and mycorrhizal treatments was including non-use of mycorrhizal and use of Glomus mosseae, G. intraradices, G. etunicatum and G. verciform. Some morphological traits including height, root length, root volume and root density, fresh and dry weight of leaf, stem and root, leaf area, number of leaf damage, leaf area, leaf diameter and symbiosis percent of grape roots with fungi were measured.
Results and Discussion: The results showed that mycorrhizal and 100% irrigation treatments increased the fresh and dry weight of leaf, stem and root, leaf area and the percentage of mycorrhizal symbiosis. Due to irrigation, the indices measured in the experiment such as height, fresh and dry weight of root, leaf and stem decreased, so that the decrease in without mycorrhizal plants was more than the with mycorrhizal plants. Generally, the use of mycorrhiza in this research has reduced the damaging effects of water stress on the morphological characteristics of grapevine, which in between the G. verciform and G. etunicatum were better than the G. mosseae and G. intraradices.
Conclusion: Grapevine phosphorus deficiency is usually rarely observed, not only mainly because of limited phosphorus requirement, but also because of sufficient phosphorus richness in the majority of vineyard soils and remobilization from bark, wood, and roots during periods of high P demand. Nevertheless, P deficiency have been described in vineyards in Australia, France, Germany and USA. Phosphorus deficiency symptoms correspond to stunt shoot growth, decrease in dry matter, and berry clusters.
Mycorrhizal treatments helped in alleviation of drought stresses. Enhanced uptake and storage of P, beyond what is required for immediate vegetative growth may be of particular importance for heavily pruned crops like grapes, since most of the new shoot growth is removed every year. These results were achieved in the greenhouse under almost controlled conditions and can be difficult to suggest for applying in the field conditions. Such experiments may be organized in the field conditions.
Present-day vineyard practices place several constraints on the use of functions provided by mycorrhiza. The risk of large, costly, or irreversible changes is to be reduced or averted. Future (modern) agriculture should be based on the implementation of ecological management practices that deliberately maintain resilience of ecosystem services. This means integrating the development of vineyard management strategies that optimize the impact of beneficial microbes like mycorrhizal fungi on production. Furthermore, AMF vary in their ability to provide ecological services so that suitable tools have to be defined to fully assess their contribution. Molecular tools have considerably improved the possibility to identify and monitor mycorrhizal fungi in ecosystems, but a quick and reliable test for assessing their functionality is still lacking. For producers’ expectations to be met, a novel industry encompassing soil/mycorrhiza analyses and advice to producers/managers is needed. Additional barriers to rationally exploiting beneficial soil microbes like mycorrhizal fungi as ecosystem services range from economical, technical, and cultural aspects to legislative questions. In spite of this, considerable progress has been made in the last decade for crop plants in general, but also for grapevine, towards the use of AMF.
Mohsen Mahmoodnia; Mohammad Farsi; Seyyed Hassan Marashi; Parviz Ebadi
Abstract
Investigation of the cultivated tomato plant as a plant ideal system along with the drought resistant wild species can be useful to a better understanding of the mechanisms of drought resistance and improvement of tomato plants. To investigate the effect of drought stress on leaf Relative Water Content ...
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Investigation of the cultivated tomato plant as a plant ideal system along with the drought resistant wild species can be useful to a better understanding of the mechanisms of drought resistance and improvement of tomato plants. To investigate the effect of drought stress on leaf Relative Water Content (RWC), electrolyte leakage and photosynthetic parameters in four species of tomato (a cultivated species and three wild species) at two levels of irrigation (field capacity and 40% field capacity) and four time periods (before stress, 10 days after stress, 20 days after stress and recovery) a factorial experiment based on Completely Randomized Design (CRD) was used. Among the tested species, cultivated species showed the highest decrease in RWC. Electrolyte leakage was significantly increased in stress conditions. The rate of photosynthesis and chlorophyll fluorescence yield in the two drought resistant wild species increased in stress conditions unlike of cultivated species, probably because of more adaptation of these species with low water conditions. The results showed that each of these species according to their own mechanism for dealing with drought stress, in one or more properties are superior to other species. it is therefore suggested that the different species for future studies (molecular) with different characteristics to be used.
