Pomology
M. Fattahi; Sh. Pourmoghadam
Abstract
Introduction
Almond (Prunus amygdalus) is considered to be able to tolerate drought stress fairly well during all stages of growth. Water shortages are very frequent in many countries, and, together with the rising demand for the industry, the growth of the human population, climate change and ...
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Introduction
Almond (Prunus amygdalus) is considered to be able to tolerate drought stress fairly well during all stages of growth. Water shortages are very frequent in many countries, and, together with the rising demand for the industry, the growth of the human population, climate change and specifically the trend towards irrigated agriculture, have led to widespread problems of water scarcity in most countries. Plant responses to water deprivation are usually monitored through selected morphological and physiological parameters which have been proven to be good indicators of drought in different studies. Chlorophyll a (Chl a) fluorescence, produced by the Chl a molecule after excitation by light, is a non-invasive and rapid biomarker for the assessment of stress (microbial and environmental) effects on PSII, as well as its structure and function. Fluorescence induction patterns and derived indices have been used as empirical diagnostic tools in stress physiology. The aim of this study was to investigate the effect of water stress on chlorophyll fluorescence parameters in two almond genotypes. It is known that the kinetics of fluorescence transients are polyphasic when plotted on a logarithmic time scale labeled as OJIP. This curve rises from an initial low-value F0 (minimal fluorescence) to FJ (fluorescence value at 2 ms) and FI (fluorescence value at about 20–30 ms) and a peak of fluorescence FP (maximal fluorescence or Fm).
Materials and Methods
The Experiment was carried out under a completely randomized design with split arrangement having three replications. Chlorophyll and carotenoid contents were determined by the method of Lichtenthaler (1986). Fresh leaves (1 g) were triturated in 80% acetone. The absorbance of the extracts was measured at 645, 663, and 470 nm using a spectrophotometer. Chlorophyll fluorescence was measured 40 days after the start of drought treatment. Full expanded leaves were selected from each plant for measurements. They were measured with a portable photosynthetic efficiency analyzer model (Hansatech, United Kingdom). Calculations were made with computer-assisted analysis using the SPSS 25 software.
Results and Discussion
The results showed that the maximum total fresh and dry mass was recorded in the Mamaei cultivar. The drought stress caused a significant reduction in a, b, total chlorophyll and carotenoids in Rabie (R) as well as Mamaei (M) cultivars but in general, M plants had higher content of pigments in comparison with R plants under drought stress. In both of cultivars, the potential efficiency of PSII photochemistry (Fv/Fm) was reduced with an increasing drought intensity. The reduction of Fv/Fm was accompanied by a decline in Fv and Fm. The VJ, relative variable fluorescence at J step (2 ms), was increased with increase in drought levels. Plants response to drought depends on PSII ability to respond to this stress. It has been reported that water limitation reduces the quantum yield of PSII electron transport, which in turn decreases the amount of light energy reaching the reaction centers. PSII plays a pivotal role in mediating oxygen evolution activity. In our study, we observed an interaction between cultivar and drought treatment, particularly evident in parameters such as Fm, Fv, Fv/Fm, and PI. Additionally, our findings revealed a robust correlation between the Pi index and total chlorophyll content (0.647), as well as the fresh (0.685) and dry (0.695) weight of plants. Furthermore, our results indicate that drought stress significantly impairs the growth of cultivars grafted on GN15 rootstock. This may be the outcome of the inhibition of water shortage on the photosynthetic apparatus. The results discovered that carotenoids were higher in M cultivar than R cultivar, carotenoids protect the photosynthetic apparatus from photooxidative damage. Protection is afforded by quenching of the triplet state of chlorophyll, thereby preventing the formation of harmful oxidative species. We also found the performance index is the parameter that better reflects the responses of the studied cultivars to progressive drought stress.
Conclusion
We applied chlorophyll fluorescence as a biomarker to assess the growth response and PSII behavior and performance of two almond cultivars to different drought levels. In conclusion, Mamaei was less affected by drought stress in terms of total Chl, Fv/Fm, PI, and total fresh and dry weight followed by Rabie. Differential responses among cultivars under drought stress treatments were observed regarding their capacity to induce PSII activity. Parameters derived from the JIP test proved effective in characterizing the degree of response to drought stress, with PI serving as a particularly responsive multi-parametric expression.
Medicinal Plants
M. Amani; M. Sabzi-Nojadeh; S. Alizadeh Salteh; M. Younessi Hamzekhanlu; B. Farmani; H. Hatef Heris; Sh. Mohammadian; S. Piretarighat
Abstract
Introduction
Medicinal plants have long had a special role in the traditional agricultural system of Iran and the use of these plants as medicine to prevent and treat diseases has been considered by traditional medicine experts since ancient times. Medicinal plants with rich sources ...
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Introduction
Medicinal plants have long had a special role in the traditional agricultural system of Iran and the use of these plants as medicine to prevent and treat diseases has been considered by traditional medicine experts since ancient times. Medicinal plants with rich sources of secondary metabolites provide the basic active ingredients of many medicines. Although the biosynthesis of secondary metabolites is genetically controlled, but their construction is strongly influenced by environmental factors. One of the important climatic factors that affect the distribution of plants around the world and can cause morphological, physiological and biochemical changes in the plant is the lack of available water. Basil seems to show little resistance to water stress. For this reason, there is a need for protective mechanisms for the basil plant against stress due to water shortage. Plants are able to reduce or eliminate the effects of water shortage stress by coexisting with a number of soil microorganisms. Inoculation of the plants with Arbuscular mycorrhizal fungi (AMF) has been exploited as an applicable strategy for reducing detrimental effects of water deficit stress. Present study was performed to evaluate the effects of three AMF on some physiological responses of Ocimum basilicum under water deficit stress.
Materials and Methods
The pot experiments were conducted as factorial based on completely randomized design blocks with three replications. The experimental factors were three AMF namely Glomus etunicatum, Glomus mosseae and Glomus intraradices and various soil moisture including severe stress, moderate stress, mild stress. Water stress was applied from the beginning to the end of flowering stage. After flowering stage, plants were harvested and traits such as total phenols and flavonoids, antioxidant capacity (DPPH), malondialdehyde (MDA), catalase and peroxidase enzymes were measured. To analyze the data, first the test of data normality and uniformity of variance within the treatment was performed and confirmed. The mean of treatments was compared by Duncan test at the level of 5% probability. SAS software (Ver. 9.3) was used to analyze the data and Excel software was used to draw the graphs.
Results and Discussion
The results of analysis of variance of the effect of mycorrhiza fungus and soil moisture on the studied parameters show that the effect of different levels of soil moisture on all traits was significant. The results of analysis of variance also showed that the effect of mycorrhiza on phenol and total flavonoids, antioxidant activity, catalase and peroxidase and malondialdehyde was significant at the level of one percent probability. According to the results of analysis of variance, the interaction effect of mycorrhiza on soil moisture on antioxidant activity was significant at 5% probability level and on total phenols and flavonoids, malondialdehyde, catalase and peroxidase at 1% probability level. Results showed that AMFs improve activity of catalase and peroxidase, antioxidant capacity and total phenols which led to decrease malondialdehyde content. Antioxidants as physiologically active compounds play an important role in plant resistance to stress. Increased oxygen species due to dehydration stress are a warning sign for plants and increase the activity of antioxidant enzymes. The plant's defense system increases the production of antioxidant enzymes to neutralize toxic oxygen forms, and fungi improve the intensity of this increase, which may be due to the chemical structure of the metal isoenzymes copper, zinc, and manganese. Factors sent to make antioxidant enzymes also contain the elements zinc and calcium. Mycorrhizal fungi increase the absorption of nutrients by sending more hormonal factors and increasing the activity of enzymes, all of which can be effective in increasing the activity of antioxidant enzymes.
Conclusion
When plants are exposed to dehydration stress, reactive oxygen species in them increase. The expression of antioxidant genes and the activity of antioxidants to eliminate reactive oxygen species are increased and the antioxidant defense system is improved and the tolerance to dehydration stress in the plant is increased. Scientists believe that peroxidase is involved in metabolic processes such as hormone catabolism, defense against pathogens, phenol oxidation, binding to cell structural proteins and cell wall polysaccharides. Present study revealed that application of AMFs can be good strategy for reducing harmful effects of water deficit stress in plants. Research has also shown that impregnating seeds with mycorrhiza increases antioxidants and reduces the amount of reactive oxygen species, a characteristic of resistance induction that occurs by this antagonist.
Medicinal Plants
M. Ghojavand; P. Kasraie; H. Tohidimoghadam; M. Naseri; H. Larigani
Abstract
Introduction
Satureja hortensis L. is an annual herbaceous plant of the mint family that has numerous raised or creeping stems or arched stems with a height of 10 to 30 cm. The height of this plant reaches a maximum of 60 cm. The stems and branches are usually covered with hairs. The leaves are ...
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Introduction
Satureja hortensis L. is an annual herbaceous plant of the mint family that has numerous raised or creeping stems or arched stems with a height of 10 to 30 cm. The height of this plant reaches a maximum of 60 cm. The stems and branches are usually covered with hairs. The leaves are opposite, have short or almost no petioles. The leaves are opposite, the petioles are short or almost without petioles, there are many small spots on the surface of the leaf called the tuber, which contains the essential oil. Knowledge of environmental, plant and agro-factors play an important role in the success of medicinal plants. One of the factors affecting the growth and development and production of active ingredients of medicinal and aromatic plants is water, the lack of which has a greater effect on reducing production than other inputs. Drought stress is an important global constraint on agricultural production and food security. Recently, there has been a growing interest in reducing the use of chemical fertilizers and exploring alternative methods for producing high-quality crops. This is particularly important in arid and semi-arid regions like most parts of Iran, where soil nutrient levels are often low. The use of biofertilizers can help strengthen plants and promote sustainable crop production. The objective of this study was to examine the impact of salicylic acid foliar application, Mycorrhiza-Azotobacter bio-fertilizers, and drought stress on the morphological and physiological characteristics of summer savory, a medicinal plant.
Materials and Methods
This experiment was conducted to evaluate some traits of summer savory in response to biological fertilizers, salicylic acid and drought stress in Zamanabad village of Rey city (Tehran province) during 2018 and 2017. This experiment was conducted using a randomized complete block design with three replications, as a factorial split plot. The main factor was irrigation, with three levels including soil moisture potential (as a control), potential of -5.5 atmospheres as medium stress, and potential of -10 atmospheres as severe stress. Sub-factors included four levels of biological fertilizers: No inoculation, seed inoculation with Azotobacter strain, seed inoculation with Mycorrhiza, and concomitant use of Azotobacter + Mycorrhiza. Salicylic acid was also considered at two levels: no foliar application and foliar application with a concentration of 0.6 mM. The following plant characteristics were studied: plant height, root dry weight, shoot dry weight, total chlorophyll content, proline content, percentage, and essential oil yield. At full flowering stage, the plants were harvested and placed in an oven at 75 ° C for 24 hours to measure the dry weight of roots and shoots. 10 g of leaves and flowering twigs from each replicate were transferred to the laboratory to measure physiological traits. SAS 9.4 software was used to perform a two-year combined analysis of variance for the recorded traits. To ensure the uniformity of variance of errors, the Bartlett uniformity test of variance was performed based on the mean squares and the degree of error freedom in two years. Mean traits were also compared using the least significant difference test (LSD) at the 5% probability level.
Results and Discussion
The results showed that the effect of drought stress, fertilizer and salicylic acid treatments on the studied traits of plant height and shoot and root dry weight, chlorophyll content, percentage and yield of essential oil and proline content were significant. Salicylic acid and the combined application of Azotobacter + mycorrhiza increased plant height, plant dry weight and root, as well as increased chlorophyll content, proline, percentage and yield of safflower essential oil under drought stress. According to the results of this experiment, it can be argued that the response of plant height, plant dry weight and essential oil yield to the increase in drought stress levels was negative, but the root dry weight, total chlorophyll, proline and essential oil percentage were the opposite response. The highest amount of these traits was observed in severe stress conditions and the combined application of bio-fertilizers (Azotobacter + Mycorrhiza) and salicylic acid 0.6 mM had a positive and increasing effect compared to other levels of bio-fertilizer and salicylic acid in The studied traits of the present study were observed.
Conclusion
According to the results of this experiment, the application of bio-fertilizers and foliar application of salicylic acid causes dehydration and dehydration, as well as the presence of essential oils, nutrients, and the quality of summer safflower under drought stress.
Heshmat Omidi; Fatemeh Pirjalili; Khadijeh Ahmadi
Abstract
Introduction: Water deficit is one of the major abiotic stresses, which adversely affects crop growth and yield. Plants use two different strategies, including drought avoidance and drought tolerance to grow under drought stress. Drought avoidance species are able to have a normal growth, which is due ...
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Introduction: Water deficit is one of the major abiotic stresses, which adversely affects crop growth and yield. Plants use two different strategies, including drought avoidance and drought tolerance to grow under drought stress. Drought avoidance species are able to have a normal growth, which is due to: 1) efficient and fast metabolism, 2) high uptake of water and nutrients, and 3) little production of secondary metabolites under deficient water conditions. While drought tolerance species maintain their regular growth, under drought stress, by: 1) adjustment of osmotic potential, 2) changes in cell wall properties, and 3) production of antioxidants and secondary metabolites, these species under prolong drought, and irrespective of plant type, plant produces higher rate of secondary metabolites, as a non-enzymatic mechanism. Such products are able to maintain plant activities, under oxidative stress, and in the presence of high rate of reactive oxygen species. Medicinal plants, including Balangu (Lallemantia royleana Benth.), are cultivated across different parts of the world including Iran for food and biodiesel purposes. Investigating the effects of drought stress on the production of secondary compounds by medicinal plants is an important issue. According to the previous studies drought stress increases the production of secondary compounds affecting the quality of medicinal plants. This must be considered when developing tolerant medicinal plants under stress, especially if the quality of medicinal plants is of higher importance than their quantity. The tolerance of medicinal plants is different under stress. Due to the importance of drought and its effects on the growth and the quality of medicinal plants, in this research the effects of stress intensity and plant species on the growth and physiology (including the medicinal contents) of Balangu plants were investigated. To our knowledge, there are not much data on such effects. The objectives of this study were to investigate the effects of drought stress on: 1) Balangu growth and yield, and 2) Balangu physiology including the activities of morphological traits, yield components and oil yield and the production of antioxidant enzyme affecting plant medicinal content. Materials and Methods: This study was conducted to investigate grain yield, yield components, and superoxide dismutase enzyme in three populations of Balangu (Lallemantia royleana Benth.) under drought stress. This study was conducted as a split plot experiment based on randomized complete block design with three replications at the experimental field of Shahed University during 2013-2014 growing season. The main factor consisted of four levels of drought stress (soil moisture content of -0.5, -3.5, -6.5 and -9 atm) and three Balangu Shirazi populations (Mashhad, Kerman and Taleghan) as sub-factors were considered. The main factor included drought stress levels at four levels (soil moisture content of -0.5, -3.5, -6.5 and -9 atm) and three Balangu Shirazi populations (Mashhad, Kerman and Taleghan) were considered as sub-plots. Measured traits were included root length, plant height, fresh and dry weight per plant, grain yield, grain yield components, mucilage percent and yield. In order to study the morphological traits, seven plants of each plot were selected with consideration of marginal impacts. About four square meters of each plot was harvested at maturity for determination of yield and its components.. The analysis of variance was does through SAS 9.12 statistical program and the means were compared by Duncan's multiple range test in 5% level. Results and Discussion: A set of yield and biochemical properties of three different species of Balangu which were affected by drought levels were determined. According to the analysis of variance the yield and biochemical properties of Balangu were significantly affected by drought, and there were significant differences between three species. The results showed that drought stress had a significant effect on growth components, yield components, grain yield, and oil yield and superoxide dismutase enzyme. With decrease of soil water content, plant height traits (24.73 cm), the number of branches (5.44), fresh (17.36 g) and dry (3.80 g) weight of plant, 1000-grain weight (1.51 g), harvest index (6.41 %), grain yield (157 kg.ha-1) and oil yield (37.77 kg.ha-1) decreased. Root length and superoxide dismutase content increased by 24.02 and 66.63% under severe stress compared to no stress condition, respectively. The highest grain and oil yield was obtained in Mashhad population under drought stress. In relatively severe stress conditions, the grain and oil yield of Taleghan population increased with the mean of 315.75 and 86.5 kg.ha-1, respectively. Under drought stress levels, the lowest reduction was observed in some growth characteristics and grain yield of Kerman population. Conclusion: Overall, the results of this study demonstrated that drought stress at flowering stage increased root length and superoxide dismutase enzyme of the studied populations. Furthermore morphological traits, grain yield components, harvest index, relative water content, grain yield and seed oil of Balangu populations were decreased. The highest seed and oil yield gained under moderate stress which belongs to Taleghan population and Mashhad population revealed the highest seed and oil yield under mild stress. Therefore, given the high stresses, introducing high-yielding populations under relatively severe stresses can lead to water use efficiency and irrigation management. Finally, the production of Taleghan population under relatively severe conditions such as arid and semi-arid cropping systems is recommended.
Ali Akbar Shokouhian; Gholamhossein Davarynejad; Ali Tehranifar; Ali Imani; Ali Rasoulzadeh
Abstract
Introduction: One of the microbiological preparations used for this study was Effective Microorganisms (EM), being a commercial mixture of photosynthesizing bacteria, Actinomycetes, lactic acid bacteria, yeasts and fermenting fungi. The microbiological composition of the EM concentrateincludesStreptomyces ...
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Introduction: One of the microbiological preparations used for this study was Effective Microorganisms (EM), being a commercial mixture of photosynthesizing bacteria, Actinomycetes, lactic acid bacteria, yeasts and fermenting fungi. The microbiological composition of the EM concentrateincludesStreptomyces albus, Propioni bacterium freudenreichil, Streptococcus lactis, Aspergillus oryzae, Mucor hiemalis, Saccharomycescerevisiae and Candida utilis. Moreover, EM also contains an unspecified amount of Lactobacillus sp. Rhodo pseudomonas sp. and Streptomyces griseus. Effective Microorganisms have a positive effect on the decomposition of organic matter, limiting putrefaction, increasing nitrogen content in the root medium of plants, phosphorus, improving soil fertility and as a result contributing to the growth and development of the root systems of plants.
Selection of almond vegetative rootstocks for water stress tolerance is important for almond crop production in arid and semi-arid regions. The study of the eco-morphological characteristics that determine the success of a rootstock in a particular environment is a powerful tool for both agricultural management and breeding purposes. The aim of this work was to select the new rootstocks for water shortage tolerance, impact of water stress as well as Effective Microorganism (EM) on morphological characteristics of almond rootstocks.
Materials and Methods: In order to select the new rootstocks for water shortage tolerance, impact of water stress as well as EMonmorphologicalcharacteristics of almondrootstocks were studiedin thedepartment ofHorticulture, Ferdowsi University of Mashhad, in 2011-2012. The experiment was carried out with four replications in a completely random blockdesign to study the effects of two concentrations of EM (0 and 1%), three irrigation levels (normal irrigation 100%-control-and irrigation after depletion of 33 and 66% of available water), and four almond rootstocks including GF677 and selected natural hybrid of peach × almond (H1and H2), and almond vegetative rootstock (local control).In this study,EMtreatments for 60 days before stress treatments were applied so that in each irrigation, EM solution to a concentration of one percent was given to half of the experiment pots. Other pots were irrigated equally with normal water. Stress levels were applied from July as follow: full irrigation, watering after unloading 33% and 66% soil moisture availability. In order to evaluate the performance, seedling survival, plant growth, number of leaves, leaf area, root fresh and dry weight and leaves and root length were measured.
Results and Discussion: Analysis of variance showed that between rootstock levels across all treatments were significantly differences at 0.01 level of probability. Comparison of means showed that the highest fresh and dry weight and leaf are awere observed forGF677and H1.Rootstockannualgrowth rate was also different. Most of the growth was related to the H1 Rootstocks. Thes urvival ratewas significantly different from the Rootstocks ofGF677,andH1showedthe highestpercentage of survival. The degree of adaptation to drought in varieties of almonds is different. The results showed that changes ingrowthparametersinGF677and H1were observed less often than other rootstocks. Because of strong roots,GF677and H1continue to attract more minerals under stress conditions.
Analysis of variance showed that the between irrigation levels for all treatments were significantly different at 0.01 level of probability. Comparison of means showed that among the study traits, the highest amount was obtained from complete irrigation, while irrigationat66 percenthad the least amount. Water stress may directly affect photosyn thesis, through leaf photochemicalprocessorindirectly,byclosing stomata, reducingleaf area and growth.
The results showed that the levels of(EM) on the leaf surface, leaf number, annual growth, root dry weight and volume were significantly different (p
Abstract
Introduction: One of the microbiological preparations used for this study was Effective Microorganisms (EM), being a commercial mixture of photosynthesizing bacteria, Actinomycetes, lactic acid bacteria, yeasts and fermenting fungi. The microbiological composition of the EM concentrateincludesStreptomyces ...
Read More
Introduction: One of the microbiological preparations used for this study was Effective Microorganisms (EM), being a commercial mixture of photosynthesizing bacteria, Actinomycetes, lactic acid bacteria, yeasts and fermenting fungi. The microbiological composition of the EM concentrateincludesStreptomyces albus, Propioni bacterium freudenreichil, Streptococcus lactis, Aspergillus oryzae, Mucor hiemalis, Saccharomycescerevisiae and Candida utilis. Moreover, EM also contains an unspecified amount of Lactobacillus sp. Rhodo pseudomonas sp. and Streptomyces griseus. Effective Microorganisms have a positive effect on the decomposition of organic matter, limiting putrefaction, increasing nitrogen content in the root medium of plants, phosphorus, improving soil fertility and as a result contributing to the growth and development of the root systems of plants.Selection of almond vegetative rootstocks for water stress tolerance is important for almond crop production in arid and semi-arid regions. The study of the eco-morphological characteristics that determine the success of a rootstock in a particular environment is a powerful tool for both agricultural management and breeding purposes. The aim of this work was to select the new rootstocks for water shortage tolerance, impact of water stress as well as Effective Microorganism (EM) on morphological characteristics of almond rootstocks.Materials and Methods: In order to select the new rootstocks for water shortage tolerance, impact of water stress as well as EMonmorphologicalcharacteristics of almondrootstocks were studiedin thedepartment ofHorticulture, Ferdowsi University of Mashhad, in 2011-2012. The experiment was carried out with four replications in a completely random blockdesign to study the effects of two concentrations of EM (0 and 1%), three irrigation levels (normal irrigation 100%-control-and irrigation after depletion of 33 and 66% of available water), and four almond rootstocks including GF677 and selected natural hybrid of peach × almond (H1and H2), and almond vegetative rootstock (local control).In this study,EMtreatments for 60 days before stress treatments were applied so that in each irrigation, EM solution to a concentration of one percent was given to half of the experiment pots. Other pots were irrigated equally with normal water. Stress levels were applied from July as follow: full irrigation, watering after unloading 33% and 66% soil moisture availability. In order to evaluate the performance, seedling survival, plant growth, number of leaves, leaf area, root fresh and dry weight and leaves and root length were measured.Results and Discussion: Analysis of variance showed that between rootstock levels across all treatments were significantly differences at 0.01 level of probability. Comparison of means showed that the highest fresh and dry weight and leaf are awere observed forGF677and H1.Rootstockannualgrowth rate was also different. Most of the growth was related to the H1 Rootstocks. Thes urvival ratewas significantly different from the Rootstocks ofGF677,andH1showedthe highestpercentage of survival. The degree of adaptation to drought in varieties of almonds is different. The results showed that changes ingrowthparametersinGF677and H1were observed less often than other rootstocks. Because of strong roots,GF677and H1continue to attract more minerals under stress conditions.Analysis of variance showed that the between irrigation levels for all treatments were significantly different at 0.01 level of probability. Comparison of means showed that among the study traits, the highest amount was obtained from complete irrigation, while irrigationat66 percenthad the least amount. Water stress may directly affect photosyn thesis, through leaf photochemicalprocessorindirectly,byclosing stomata, reducingleaf area and growth.The results showed that the levels of(EM) on the leaf surface, leaf number, annual growth, root dry weight and volume were significantly different (p
