Breeding plants for stress conditions
Hadi Tayfa Afshari; Bahram Mirshekari; Abollah Hasanzadeh Ghorttapeh; Farhad Farahvas; Mehrdad Yarnia
Abstract
IntroductionThe castor bean (Ricinus communis L.), is an oilseed of relevant economic and social importance. From its seeds is extracted an oil of excellent properties, having wide use as industrial input and several applications. It is cultivated since the times of the ancient civilizations, the castor ...
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IntroductionThe castor bean (Ricinus communis L.), is an oilseed of relevant economic and social importance. From its seeds is extracted an oil of excellent properties, having wide use as industrial input and several applications. It is cultivated since the times of the ancient civilizations, the castor bean is a rustic plant, resistant to drought, belonging to the family of Euphorbiaceae, Drought stress, in addition to the negative effect on yield, causes or exacerbates other stresses, especially the stress of nutrient deficiencies for the plant. The purpose of this investigation was to study the effect of irrigation levels and Superabsorbents and biofertilizers on the agronomic properties of castor oil.Materials and methodsThis experiment was conducted in West Azarbaijan Agricultural Research and Education Center, Orumieh- Iran in 2018-2021 crop season. A field experiment was carried out by a split-plot design based on a completely randomized block design with three replications. The first factor included Four levels (70, 100, 130, and 160 mm of evaporation pan), in the main plot and Sub-factor includes application of biofertilizer combination in four levels (Azospirillium, Citrobacter, combination of application of Azospirillium in Citrobacter and control without fertilizer) and superabsorbent in two levels (superabsorbent consumption and non-superabsorbent consumption) as factorial were placed in sub-plots. In this study, Chlorophyll a, Chlorophyll b, Cartonoid, Soluble sugar, prolin content, Catalase, Malondialdehyde, and protein content were measured. Also Traits were analyzed by using SAS 9.2 software and means comparison was tested by least significant difference (LSD).Results and discussionBased on the results of the combined analysis of the variance of the data, there was a significant difference in was observed between the two years in terms of malondialdehyde content. There was a significant difference between the irrigation levels in terms of the effect on all traits of the probability level of 1%. The interaction effect of year and irrigation was significant only on leaf proline content at the level of 1% probability. There was a significant difference between the biofertilizer treatments and the interaction effect of biofertilizer on irrigation and superabsorbent levels in terms of the effect on all traits at the level of one percent probability. The interaction effect of irrigation with superabsorbent on chlorophyll a and b content and soluble sugar content at 1% probability level and on proline content and protein percentage at 5% probability level was significant. Between treatments of biofertilizer with superadd interaction in terms of the effect on chlorophyll b content, soluble sugar, proline content, malondialdehyde content, and protein percentage at the level of 1% percent and in terms of the effect on chlorophyll content, carotenoids and catalase activity in 5% probability level There was a significant difference. The results showed the highest chlorophyll a (23.00 mg g-1) and b content (14.93 mg g-1) as well as carotenoids (30.39 mg g-1) and the lowest amount of soluble sugar (113.33 micromol g-1 fresh weight), catalase (32.97∆A240 mg-1 protein), malondialdehyde (132.44 nmol g-1FW) and protein percentage (4.69%) were assigned to with Citrobacter treatment and irrigation after 70 mm of evaporation. Also, the highest soluble sugar content (131.42 micromol g-1 FW), proline (65.91 micromol g-1 FW), protein (11.48 %) was assigned to the treatment with Azosprilium + Citrobacter and irrigation after 160 mm of evaporation. In this study, the use of superabsorbent in the irrigation treatment of 70 mm evaporation had the highest chlorophyll a (21.29 mg g-1) and b content (12.78 mg g-1) and the lowest amount of soluble sugar (112.50 micromol g-1 FW), proline (26.50 micromol g-1 FW), catalase (35.99 ∆A mg-1 protein) and protein percentage (5.00%), While the highest soluble sugars content (129.12 micromols g-1 FW), proline (58.70 micromols g-1 FW), malondialdehyde (159.71 nmol g-1 FW), and protein (10.37 %), was observed in the treatment of superabsorbent application along with irrigation after 160 mm. In this study, the simultaneous application of superabsorbent and inoculation with azospirlium showed the highest chlorophyll a (22.25 mg g-1), b content (13.79 mg g-1), carotenoid (29.02 mg g-1), protein (7.99%) and the lowest content of catalase enzyme (39.58 ∆A240 mg-1 protein), The highest soluble sugar content (122.88 micromol g-1 FW) and the lowest amount of malondialdehyde (141.82 nmol g-1FW) were detected in the treatment of superabsorbent application with Citrobacter.ConclusionIn this study, water deficit had an adverse effect on the physiological properties of castor oil. However, the use of biofertilizers and superplasticizers by improving biochemical and antioxidant properties was able to moderate the effect of drought stress on physiological properties and stabilize photosynthetic pigments, and the stability of photosynthetic pigments can improve photosynthetic properties and plant growth under water deficit conditions.
Drought stress
Diba Sheykhi Sanandaji; Gholamreza Heidari; Parviz Fathi; Zahed Sharifi; Habib Khodaverdiloo
Abstract
IntroductionQuinoa (Chenopodium quinoa Willd) is a member of Amaranthaceae family. This plant is annual and has seeds with high nutritional value. Quinoa seeds contain a high percentage of protein and essential amino acids, which are low in other plants. Using high-efficiency irrigation systems such ...
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IntroductionQuinoa (Chenopodium quinoa Willd) is a member of Amaranthaceae family. This plant is annual and has seeds with high nutritional value. Quinoa seeds contain a high percentage of protein and essential amino acids, which are low in other plants. Using high-efficiency irrigation systems such as drip irrigation system, increasing water productivity and modifying the cultivation pattern and using alternative low-consumption plants are among the effective solutions for saving water consumption and sustainable development in the agricultural sector. The use of vermicompost, which is obtained as a result of the continuous and slow passage of organic materials through the digestive system of surface earthworm species and the removal of these materials from the worm's body, is a sustainable solution to maintain production and improve fertility. The soil is especially in arid and semi-arid areas that face a lack of soil organic matter.Materials and methodsThis experiment was conducted as a split plot based on randomized complete block design in the research farm of University of Kurdistan located in Dehgolan in 1400. The experimental factors included 4 levels of irrigation equal to 50, 75, 100 and 125% of the water requirement of the quinoa plant were assigned to main plots and 4 levels of vermicompost fertilizer equal to zero, 5, 10 and 15 tons per hectare were assigned to sub plots. The irrigation method used in this experiment was drip-strip irrigation system. In this study, the irrigation cycle was considered constant and equal to seven days. The distance between irrigation strips in each plot was equal to 50 cm. The amount of irrigation water was measured by a volumetric meter installed on the main pipe. At the end of the growth period, by removing the marginal effect of two square meters from each plot, the aerial parts were harvested in order to obtain the seed yield. Nutrient elements in quinoa seeds include nitrogen by Kjeldahl titration method, phosphorus, potassium by flame diffusion method and with the help of film-photometer device, sodium and calcium and micronutrient elements such as zinc, iron, copper and manganese by absorption device. atomic, were measured.Results and discussionThe results of analysis of variance obtained from the data of this research showed that the interaction effect of different levels of irrigation × vermicompost on grain yield traits, concentration of nitrogen, calcium, zinc and iron elements was significant. However, the concentration of phosphorus, potassium and magnesium elements under the influence of independent effects of different levels of irrigation and vermicompost became significant at the probability level of 1%. The concentration of sodium and copper elements were significant only under the influence of different irrigation levels. The results showed that the highest grain yield (2374.51 kg.ha-1), zinc concentration (20.22 mg.kg-1) and iron concentration (400.92 mg.kg-1) in The treatment was 125% of plant water requirement and 15 tons of vermi-compost per hectare. Also, the highest concentration of elements phosphorus (0.35%), potassium (4.31%) and copper (4.63 mg.kg-1) was observed in the treatment of 125% of plant water requirement. The highest concentration of nitrogen (2.6%), sodium (1.37%) and manganese (55.61 mg.kg-1) of quinoa seeds was observed in the treatment of 50% of plant water requirement.ConclusionThe results of the present experiment showed that the application of different levels of vermicompost increases the concentration of elements in quinoa seeds. Due to the fact that vermicompost-containing substrates have a high percentage of nutrients and the release of these elements is gradual, therefore plant nutrition is more efficient and the result is an increase in the concentration of seed elements. On the other hand, due to the positive effects of vermi-compost in improving the physical and chemical properties of the soil and increasing the maintenance of soil moisture at stress levels, it increases the concentration of quinoa seed elements compared to the treatment without the use of vermi-compost.
Breeding plants for stress conditions
Marzieh Salari; Ali Kazemipour; Mehrnaz Kashigarzadeh; Soraya Pourtabrizi; MohamadGhader Ghaderi; Roohollah Abdolshahi
Abstract
IntroductionGreen Revolution which occurred by introducing dwarfing genes into bread wheat varieties had a great impact on the global wheat production. Nevertheless, these genes decrease grain yield under rain-fed conditions. In general, semi-dwarf genes may not have any advantage in heat and drought ...
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IntroductionGreen Revolution which occurred by introducing dwarfing genes into bread wheat varieties had a great impact on the global wheat production. Nevertheless, these genes decrease grain yield under rain-fed conditions. In general, semi-dwarf genes may not have any advantage in heat and drought stress conditions. In rain-fed conditions, the combination of Rht-D1b and Rht-B1b genes causes a decrease in the grain yield and coleoptile length. It should be noted that the genes Rht4, Rht5, Rht7, Rht8, Rht9, Rht12, Rht13 and Rht14, which are sensitive to gibberellic acid, do not affect coleoptile length.Materials and methodsIn the present research, wild type genes which cause higher plant height were transferred from Roshan to Excalibur variety using backcrossing. Similarly, in the F3 generation of a cross between Roshan and Mahdavi, a semi-dwarf plant was observed. This plant was backcrossed with Roshan to have semi-dwarf isogenic lines of this cultivar. Development of isogenic lines for plant height in two genetic backgrounds made it possible to study the effect of the plant height on yield and yield components. Isogenic lines and their parents were evaluated in two successive years (2020-2021 and 2021-2022) under Sepidan rain-fed conditions.Results and discussionOn average, plant height of Roshan and its semi-dwarf isogenic lines were 90.84 and 51.22 cm, respectively. Also, the average plant height of Excalibur and its tall isogenic line were 47.61 and 65.36 cm, respectively. Results showed that breeding for higher plant height had a positive and significant effect on wheat grain yield under rain-fed conditions. On average, tallness increased grain yield by 375.43 and 177.94 kg.ha in Roshan and Excalibur genetic backgrounds, respectively. In addition, the effect of plant height on yield components under rain-fed conditions was investigated. The findings of this research show that breeding for higher plant height indirectly increase grains number per spike and 1000 grain weight to improve grain yield. While, spikes number per meter square was not affected with plant height. Considering the high heritability of plant height and its significant correlation with grain yield, it is suggested that this trait be considered in breeding programs under rain-fed conditions.ConclusionIn the present research, it was found that tallness improve grains yield of bread wheat under rain-fed conditions via increasing grains number per spike. Two other yield components were also investigated and it was found that the plant height had no effect on spikes number per meter square. 1000-grains weight did not affected by plant height in the first year, although in the second year, the taller genotypes had higher 1000-grains weight. Considering that plant height has high heritability and response to selection, it is recommended to pay special attention to this trait in breeding programs for rain-fed conditions. It should be mentioned that as narrow sense heritability of plant height is very high, selection for this trait based on single plant is very effective. Consequently, selection for plant height in backcrossing and pedigree breeding methods could be extremely successful.
Drought stress
Fermisk Mrovati; Tooraj Mir Mahmoodi; Saman Yazdan Seta
Abstract
IntroductionHairy vetch a plant that can be used in different ways, such as fodder, silage, grazing, and green manure and its seeds can be used to feed poultry. Like other legume family plants, vetch can improve and strengthen the soil and fix nitrogen. Iron (Fe) is an essential micronutrient to virtually ...
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IntroductionHairy vetch a plant that can be used in different ways, such as fodder, silage, grazing, and green manure and its seeds can be used to feed poultry. Like other legume family plants, vetch can improve and strengthen the soil and fix nitrogen. Iron (Fe) is an essential micronutrient to virtually all forms of life. Although Fe is the second most abundant metal element in earth’s crust its low solubility and high fixation in soil reduce its bioavailability to the plant roots. Fe plays a major role in redox reactions in metabolic processes such as photosynthesis, respiration, and nitrogen assimilation besides being involved in the biosynthesis of chlorophyll and hormones, Drought stress is the most common environmental stress that reduces crop production, and low soil moisture leads to the lack of low consumption elements, especially iron and zinc elements in plants, So With the aim of investigating the effect of foliar application of different sources of iron fertilizer on fodder characteristics of vetch, this research was conducted.Materials and methodsThe research was conducted in the agricultural research farm of the Agricultural Jihad Organization in Baneh city in Kurdistan province, at 2021 crop season. The experimental design was implemented as a split plot where different levels of irrigation include no irrigation (rainfed conditions), one irrigation and two irrigations in the main plots, and foliar spraying of different sources of iron fertilizer including, control (spraying solution with water), iron chelate (Fe-EDTA), iron nanochelate (Khizra) and non-chelated source of iron sulfate were placed in sub-plots in three replicates. In the study chlorophyll index, plant height, fresh forage yield, dry fodder yield, Fodder protein percentage, digestibility percentage, ADF, NDF, soluble carbohydrates, crude fiber and ash percent of fodder were measured.Results and discussionThe results showed that the main effect of irrigation and foliar spraying on all investigated traits was significant. Results revealed that the interaction effect of irrigation with iron fertilizer foliar application on chlorophyll index, plant height, digestibility percentage, cell wall NDF, fiber percentage, and ash percentage was a significant, In our study dry conditions, compared to the treatment of two times of irrigation, decreased the wet fodder yield and dry fodder yield and the protein content of fodder by 71.65, 50.16, and 58.58%, respectively, and increased the insoluble fibers in the acidic cell (ADF) by 48.15%. Also, under iron nano chelate treatment of fresh and dry fodder yield, the protein content of the fodder and the content of soluble carbohydrates increased by 84.35, 40.19, 22.90 and 64.08, respectively, and the insoluble fibers in the neutral cell wall (NDF) decreased by 11.60%. Among the interaction treatments of irrigation with the iron foliar application, the highest chlorophyll content (133.45 and 131.04 mg/g fresh weight respectively), plant height (23.81 and 23.43 cm respectively), fodder digestibility percentage (72 42.42 and 77.10% respectively), fiber percentage (37.75 and 40.98 respectively) and fodder ash percentage (19.37 and 21.01% respectively) And the lowest NDF of the cell wall (21.78 and 26.93% respectively) was recorded in the treatment of iron chelate (Fe-EDTA) and iron nano chelate with two times of irrigation. The results of the interaction treatments also showed that iron chelate (Fe-EDTA) under the one-time irrigation treatment could significantly increase the leaf chlorophyll content, the percentage of forage digestibility and the percentage of forage fiber compared to the control treatment.ConclusionIt can be concluded that foliar application of iron fertilizer from sources of iron chelate (Fe-EDTA) and nano-iron chelate (Khizra) with two times of irrigation to achieve the maximum quantitative and qualitative characteristics of the fodder of the cluster flower is recommended, therefore it can be stated that supplementary irrigation and foliar application of iron fertilizer can be a solution to improve the quantitative and qualitative characteristics of fodder in vetch.
Drought stress
Mehrdad Moradi-Ghahderijani; S. Ali Mohammad Modarres-Sanavy; Ali Mokhtassi-Bidgoli; Ali Heidarzadeh
Abstract
IntroductionOne of the most important problems threatening agriculture is water deficit stress in many regions of the world. Water deficit stress could result in a decrease in yielding or death of a wide range of crops. In Iran, like other arid and semi-arid regions, forage quality and production have ...
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IntroductionOne of the most important problems threatening agriculture is water deficit stress in many regions of the world. Water deficit stress could result in a decrease in yielding or death of a wide range of crops. In Iran, like other arid and semi-arid regions, forage quality and production have decreased due to the occurrence of frequent water stress. Restriction of water resources, especially in arid and semi-arid regions where agricultural systems depend on supplementary irrigation, has become the most important problem of fodder production. Persian clover (Trifolium resupinatum L.) is a forage legume cultivated in the temperate region of world; it is of great value for livestock feed, soil improvement, and reclaiming disturbed land because of its nitrogen-fixing capability. The purpose of this research, was evaluate the effect of water deficit stress on the physiological and qualitative traits of fodder of Persian clover.Materials and methodsAn experiment was carried out during the 2016 and 2017 cropping seasons as a randomized complete block design at the Research Farm of Tarbiat Modares University. Experimental treatments included water deficit stress at four levels. The tested treatments included water deficit stress at four levels (irrigation after reaching the levels of 80, 60, 40 and 20% available moisture). Irrigation of all treatments was carried out at the level of 70% of available water until the start of stress in the final stages of vegetative growth of the second cut. To measure the effects of water deficit stress on physiological traits physiological indexes were recorded during the first 10 days of stress treatment, every day. The clovers were harvested at about 20-25% flowering stage. After drying, they were transferred to the laboratory to determine the quantitative and qualitative feed yield. Based on Bartlett's test results, the experiment's dependent variables had the same trend.Results and discussionThe results show that the irrigation regime had a significant effect on all traits. Irrigation treatments at 80 and 60% of available water had the highest dry matter yield, and delaying irrigation until 40 and 20% caused a 19% and 36% significant decrease in this trait. Also, stress at the level of 20% caused a 27% decrease in fodder protein, a 10% increase in acid detergent fiber and neutral detergent fiber, and finally, an 16% reducing relative feed value. Evaluation of physiological traits in the first ten days of the beginning of water stress showed a continuous increase in leaf temperature from 30.5 to 34 ˚C, and 49, 50, and 15% decrease in photosynthesis rate, stomatal conductance, and SPAD index, respectively. It Also reduces the concentration of chlorophyll a and b 25 and 40 percent. The return of increased leaf temperature and reduced stomatal conductance due to the discharge of 80% moisture was fast to the initial level, but other traits slowly approached the value before the stress. It seems that returning to initial values at levels of 80 and 60 is easily possible for the plant, but with the increase in the intensity of stress, the damage of dehydration is slowly compensated.ConclusionThe experiment results showed that the photosynthesis rate and other physiological traits of Persian clover significantly react to the soil's decreased available water. In most physiological traits, irrigation after the available soil moisture reached 60% caused a relatively quick return to the initial value. There was no significant difference in fodder yield in the 80% and 60% irrigation treatments. When the available soil moisture reached 40%, the physiological traits showed a greater decrease than before. It seems that some damages to physiological traits are irreparable to such an extent that they eventually lead to a drop in yield or a decrease in the quality of Persian clover fodder. Finally, it is not necessary for clover irrigation at levels of more than 60% of available water, taking into account the more quality of forage in the level of 60% (about 1.5% of insoluble fiber, and 11% feed value), considering the water conditions of the country.
Drought stress
Farzane Golestanifar; Sohrab Mahmoodi; Hamid-Reza Fallahi; Ali Shahidi
Abstract
IntroductionEnvironmental disorders that significantly disturb the growth and yield of plants are considered as stress conditions and cause disturbances in biological. Drought stress is one of these environmental conditions which has been increased as a result of climate change and has been a negative ...
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IntroductionEnvironmental disorders that significantly disturb the growth and yield of plants are considered as stress conditions and cause disturbances in biological. Drought stress is one of these environmental conditions which has been increased as a result of climate change and has been a negative effect on the yield of crops in the world. Every year about 12 million hectares of productive land has become dry and barren due to human activities and climate. More than 6000 varieties of quinoa are cultivated by farmers in the worlds. Quinoa is a plant responds to drought stress through escape, tolerance and avoidance of drought and has an extraordinary capacity for cultivation in dry and low-water soils because of its capabilities such as low inherent need for water, the maintenance of leaf surface and the ability to resume the speed of photosynthesis after drought stress. Titicaca, Redcarina and Giza-1 are three quinoa cultivars. Titicaca and Redcarina, were registered on December 14, 2009 and January 31, 2005, respectively, and are native to Denmark and Netherlands, respectively, and Giza1 is native to Egypt. Increasing yield in water deficit conditions requires the identification of genotypes resistant to drought stress. Different quantitative indicators have been provided to evaluate the reaction of genotypes in environmental conditions and also to determine their tolerance and sensitivity.Materials and methodsIn order to evaluate the indicators of drought stress tolerance of quinoa cultivars, a factorial experiment with four stress levels (100, 75, 50 and 25% of water requirement) and three varieties of quinoa (Titicaca, Giza-1 and Redcarina) were conducted with three replications in two locations (Birjand and Sarbisheh region) and two planting dates, spring (March) and summer (July) in 2018 and 2019. Evaluation of cultivars in terms of drought tolerance was done using stress sensitivity indices, such as tolerance (TOL), mean productivity (MP), stress tolerance index (STI), geometric mean productivity (GMP) and harmonic mean (HM). Decomposition into main components on yield under stress and non-stress conditions and drought stress tolerance indices were displayed in the form of a biplot diagram using STATISTICA software.Results and discussionThe results showed that in both regions the highest amount of STI, MP, GMP and HM indices, were recorded for Redcarina variety in all three levels of drought stress at spring cultivation, but they were belonged to Giza-1 at summer cultivation. Due to the dispersion of the results, SSI and TOL indices had less diagnostic power to evaluate the drought tolerance of quinoa cultivars. Principal components analysis showed that Redcarina cultivar was collinear with yield vector in stress condition and MP, GMP, STI and HM indicators and was located in yield potential and tension tolerant area in bi-plot diagram in two regions (Birjand and Sarbisheh) at spring cultivation. In summer cultivation, Giza-1 variety was located at sensitive to stress area and yield potential in bi-plot diagram and was collinear with grain yield vectors in non-stress conditions and MP, GMP, STI and HM indices in two regions. This showed the more yield of this variety in non-stress condition. In most of the planting dates and places were studied, Titicaca cultivar had collinearity with SSI vector or located at the closest position to this vector, which indicated that this cultivar was sensitive to stress.ConclusionIn general, in July, Giza-1 variety and in March Redcarina variety were the most tolerance varieties and Titicaca was most sensitive cultivar to drought stress.
Heavy metals
Rayhaneh Amooaghaie; Javad Heidari; Shahram Kiani
Abstract
IntroductionNickel (Ni) is an essential micronutrient required for optimal plant growth and development, but excessive Ni is toxic and threatens plant growth and productivity as well as human health. The removal of Ni from soil through phytoextraction is an ecofriendly technique for heavy metal remediation. ...
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IntroductionNickel (Ni) is an essential micronutrient required for optimal plant growth and development, but excessive Ni is toxic and threatens plant growth and productivity as well as human health. The removal of Ni from soil through phytoextraction is an ecofriendly technique for heavy metal remediation. But low bioavailability of metals in soil is often a limiting factor in phytoextraction. Ethylenediaminetetraacetic acid (EDTA) is recognized as a highly effective chelate that can increase soil mobility and uptake and translocation of heavy metals in plants. However, its long soil persistence time and its resistance to breakdown by soil microorganisms limits its efficiency for phytoremediation. The objective of this study was the evaluation of the effects of various concentrations of EDTA on the bioavailability of Ni in soil and the phytoremediation capacity of Ni in Calendula tripterocarpa plant.Materials and methodsIn this study, the effect of different concentrations of EDTA (0, 0.5, 1, 2 g kg-1 soil) was investigated on Calendula tripterocarpa exposed to various concentrations of nickel (0, 100, 150 mg/kg). The experiment was conducted in a completely randomized design with factorial arrangement with three replications in greenhouse. To stabilize Ni in soil, repeated cycles of saturation with distilled water was performed for 20 days. Then, EDTA was added to soil 15 days before cultivation. Seeds were sown in pots and plants grown in pots without EDTA and nickel was considered as control. After, 45 days, plants were harvested and fresh and dry weights of shoot and roots, the content of chlorophyll a, b (Chl a, Chl b), malondialdehyde (MDA) content, Ni concentration in shoot and roots, and available nickel of soil was measured and bioaccumulation factor (BAF), translocation factor and total Ni removal per pot were computed for All treatments.Results and discussionThe results revealed that with increasing nickel concentration, the growth parameters and content of Chl a, Chl b significantly reduced but the content of MDA in roots increased in comparison to the control. In non-stress condition, applying concentration of 1 and 2 g kg-1 EDTA reduced the growth parameters and content of Chl a, Chl b while increased MDA content in roots. These results indicate the toxicity of higher dose of EDTA for Calendula tripterocarpa plants. Under 100 and 150 mg kg-1 Ni in soil, applying 0.5 g kg-1 EDTA, increased nickel concentration in the aerial parts (65 and 60.35%) and roots (35 and 29.44%), translocation factor (22.5 and 25.20%) and total Ni removal per pot (27.66 and 23.44%). Interestingly, the application of 1 and 2 g kg-1 EDTA, decreased available nickel concentration in soil as well as nickel concentration in roots and shoots and translocation factor in plants. In addition, these concentrations of EDTA considerably decreased the biomass of plants and consequently reduced total Ni removal per pot.ConclusionIt can be concluded that application of 0.5 g kg-1 EDTA enhanced phytoremediation capacity of Calendula tripterocarpa. In contrast, higher concentrations of EDTA decreased available nickel concentration in soil and due to decreasing biomass and Ni concentration in roots and shoots, reduced total Ni removal per pot and impaired phytoextraction efficiency of Calendula tripterocarpa.
Salinity stress
Ali Bozorgmehr; Hamid Reza Asgary; Mohammad Farzam; Gholamhassan Ranjbar
Abstract
IntroductionSalinity of water and soil resources is one of the most basic agricultural problems, especially in arid and semi-arid regions. Identifying and domesticating salinity-resistant plant (halophytes) species with economic value is an important strategy for these regions.Materials and methodsThis ...
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IntroductionSalinity of water and soil resources is one of the most basic agricultural problems, especially in arid and semi-arid regions. Identifying and domesticating salinity-resistant plant (halophytes) species with economic value is an important strategy for these regions.Materials and methodsThis research aimed to investigate the amount of elements and the quality of fodder in several Salicornia species under the influence of water salinity in a factorial experiment with a completely randomized design in pot culture conditions in Bojnourd (North Khorasan province) in 2018. Irrigation treatment was applied at two levels (brackish water and normal water), and Salicornia species treatment included four species (Salicornia persica, S. sinus persica, S. europaea, and S. bigelovii) and Salicornia var Markazi. The source of salty water was the Kal-Shoor river in Esfrain and the source of normal water was the well located in Research and Education of Agriculture and Natural Resurces Center in Bojnourd. Due to the high salinity of Kal-Shoor river, normal water was used to adjust the salinity to the treatment limit of 45 dSm-1. To produce seedlings, Salicornia seeds were planted in plastic combs for seedling production in April 2018. After 60 days, seedlings (10-15 cm) were transferred to pots. The irrigation circuit varied in different growth stages according to weather conditions, and irrigation was done by the weight method with the 80% moisture index of the pots.Results and discussionThe results showed that the amount of nitrogen, phosphorus, potassium, magnesium, sodium and chlorine increased with the increase in irrigation water salinity in all species. The highest accumulations of sodium (11%) and chlorine (23.5%) were observed in S. sinus persica and the lowest amount of sodium (8.6%) and chlorine (21%) were observed in S. persica. Among the Salicornia species, the lowest amount of elements is related to potassium and phosphorus ions, which is mostly due to the limitation of the absorption of these elements under the influence of sodium ions, and as mentioned in the sources, the process of absorption of these elements increases gradually with the growth stages. Maintaining a more negative potential of the membrane is an important factor for salinity tolerance, considering that in saline soils, chlorine and sodium are the most common solutes, the absorption of sodium and chlorine ions is important for regulating osmotic pressure and cytoplasmic concentration. In this experiment, in both irrigation treatments, the most elements in all species were related to chlorine and sodium ions. Based on the measurement of quality variables of fodder, the percentages of protein, crude fat, and ash in salty water treatment were higher than those in normal water. The highest percentage of crude fat (1.32%) in S. var. Markazi was affected by saltwater treatment, which was significantly different from the other species. The highest percentages of protein in S. bigelovii and S. europaea under the influence of saltwater treatment were 6.06% and 6.31%, respectively, which were significantly different from the other species. The highest amounts of ash belonged to S. europaea (63%) and S. bigelovii (62%) in saltwater treatment, and S. sinus persica contained the least ash (49%) in normal water treatment. Although the increase in protein increases the quality of fodder, the increase in the amount of ash and crude fat causes limitations in animal nutrition and digestibility. Therefore, the increase of water salinity has a negative effect on the quality of fodder.ConclusionBrackish water treatment increased the amount of ash in all species to different proportions, which is a limiting factor for the pure consumption of salicornia in animal feed. Therefore, the relative reduction of water salinity and the selection of suitable species are effective in increasing the quality of fodder.On the other hand, the great ability of Salicornia species to absorb and store salts in their aerial parts provides the basis for the exploitation of their vegetative organs for the production of vegetable salt. Moreover, it is economically important along with other applications of Salicornia (production of fodder, oil, medicines, and protection).
Drought stress
Maryam Mirdoraghi; Saeideh Maleki Farahani; Alireza Rezazadeh
Abstract
IntroductionChickpea (Cicer arietinum L.) is one of the most important legumes in the world (Keifer, 2018). After India, Australia, and Pakistan, Iran has taken the fourth rank in terms of chickpea cultivation area, and the decrease in rainfall and especially the plant's exposure to heat and drought ...
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IntroductionChickpea (Cicer arietinum L.) is one of the most important legumes in the world (Keifer, 2018). After India, Australia, and Pakistan, Iran has taken the fourth rank in terms of chickpea cultivation area, and the decrease in rainfall and especially the plant's exposure to heat and drought stress at the end of the season is the reason for the decrease in crop yield (SabaghPour et al., 2010; FAO, 2018). In general, drought stress and its relationship with the reduction of yield and its components in crops plants can be primarily attributed to the closing of stomata in response to low soil water content, during which the entry of carbon dioxide into the leaf is reduced, and as a result, it causes a reduction in photosynthesis.Materials and methodsIn order to investigate the effect of irrigation regimes on the yield and yield components of chickpea (Cicer arietinum L.), an experiment was conducted at the research farm of Shahed University during 2021–2022 as a split plot design in the form of random complete blocks. The first factor is irrigation systems at three levels: 1) supplementary irrigation (Irrigation at two sowing times and before flowering based on 20% available soil water, 2) complete or control irrigation (irrigation based on 20% available soil water), 3) Low irrigation regime (irrigation based on 40% available soil water) is the second factor of autumn (November 15) and spring (March 15) sowing dates. Irrigation was carried out in the form of streams and stacks, and the ends of the plots were completely closed to prevent water from escaping. Data analysis and calculations related to simple Pearson correlation coefficients between traits were performed with SAS (ver 9.4) and SPSS (ver 23) software, respectively, and the average of treatments was compared by LSD test at a statistical level of 5%. The graphs were drawn using Excel software.Results and discussionThe results of the variance analysis of the interaction between irrigation regime and planting date showed that there is a significant difference between the traits of number of branches per plant, number of pods per plant, plant height, number of seeds per plant, harvest index, biological yield and seed yield. The results of comparing the averages also showed the highest number of branches per plant (9.83), the number of pods per plant (30.5), plant height (51.08) cm, and the number of seeds per plant (26.66). The harvest index was 0.48 percent, the biological yield was 4670 kg ha-1, and the seed yield was 2384.17 kg ha-1 for the autumn planting date treatment under the autumn irrigation regime (irrigation based on draining 20% of crop capacity moisture). The highest correlations with grain yield were obtained by traits: plant height (r = 0.986**), number of branches per plant (r = 0.966**), harvest index (r = 0.962**), number of seeds per plant (r = 0.961*), biological yield (r = 0.956**), hundred seed weight (r = 0.933**) and number of empty pods per plant (r = 0.880*).ConclusionIn general, the results of this experiment indicate that the Low irrigation regime is more efficient than Supplementary irrigation in all traits after the control irrigation regime in autumn sowing. Therefore, the Low irrigation regime is suggested as a low irrigation regime suitable for the conditions of the tested region for the sowing of chickpeas in autumn, and in addition, other autumn sowing dates of this variety should be studied.
Physiology of crops under stress conditions
Sadeg Shadkam; Soran Sharafi; Saman Yazdan Seta; Tooraj Mir Mahmoodi; Farshad Habibi
Abstract
IntroductionMedicinal plants are precious resources in Iran’s broad landscape of natural resources, which can play an essential role in health, employment, and non-petroleum export if recognized, cultivated, developed, and exploited scientifically and correctly. Given the limitation of water resources ...
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IntroductionMedicinal plants are precious resources in Iran’s broad landscape of natural resources, which can play an essential role in health, employment, and non-petroleum export if recognized, cultivated, developed, and exploited scientifically and correctly. Given the limitation of water resources in Iran, the agricultural sector’s use of unconventional water resources has been proposed as a solution. One of these methods is to pass water through a magnetic field before irrigation to improve water productivity. The soil health management is crucial for ensuring ecological and agricultural productions and maintaining plant diversity. The negative impacts of chemical fertilizers forced the agrochemical companies to replace them with Nano-fertilizers in sustainable agricultural systems in order to achieve desirable crop productivity.Materials and methodsWith the aim of investigating the effect of foliar application of different nano fertilizers on the quantitative and qualitative characteristics of peppermint under different irrigation conditions, an experimental experiment was carried out in an agricultural field in Miandoab city in West Azarbaijan province. The experiment was in the form of split plots based on randomized complete block design in three replications. The main plot was assigned to the irrigation cycle (every 5, 7 and 10 days) and the secondary plot was assigned to foliar spraying treatments (control (no foliar spraying) nano NPK, nano Fe, nano Zn and nano Mn). chlorophyll a, chlorophyll b, carotenoid, plant height, number of leaves per plant, leaf weight, fresh yield, dry yield, proline content, essential oil percentage and essential oil yield was measured.Results and discussionBased on the results of data variance analysis, all investigated traits were affected by irrigation, foliar application and the interaction of two treatments at the 1% probability level. The interaction of year with foliar application on dry and wet yield of fodder was significant at the probability level of 1%. The triple interaction of year × irrigation× foliar application and was significant only on proline content at the 1% probability level. The results of the mean comparison of irrigation with foliar application interaction treatments showed the Foliar application of nano Fe under irrigation conditions once every 5 days had the highest content of chlorophyll a, chlorophyll b and carotenoids (respectively with an average of 13.43, 3.61 and 4.12 mg g fresh weight-1), plant height (33.92 cm), leaf fresh weight (6.71 g), aerial fresh yield (13121 kg ha-1), aerial dry yield (4600.1 kg ha-1) and the lowest proline content (6.32 mmol g weight-1). Also, the highest percentage of essential oil (0.67%) was attributed to nano Fe foliar spraying under irrigation conditions of 7 days once. In this study, although the highest essential oil yield (24.74 kg ha-1) was assigned to the application of nano Zn under the irrigation once every 5 days’ condition but there was no significant difference between the mentioned treatment and Foliar application nano NPK and nano-Fe in the irrigation treatment of 7 days’ treatments.ConclusionIt can be stated that the use of NPK and Fe in the form of nanoparticles under mild water stress conditions can improve the economic performance of the product and save water consumption. Also, foliar spraying of this fertilizer it was able to significantly increase the essential oil yield of in this plant under severe water stress conditions. Therefore, foliar spraying of nutritional elements in nano form can be a solution to improve the essential oil yield in peppermint plants under water stress conditions with different intensities.
Drought stress
Mahsa Ghanizadeh; Reza Khorassani; Amir Fotovat
Abstract
IntroductionWith the approach of attention to the environment, the use of natural materials can be effective in reducing the harmful effects of chemical fertilizers and artificial growth regulators. Drought stress is one of the main limitations of food production around the world, and due to increasing ...
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IntroductionWith the approach of attention to the environment, the use of natural materials can be effective in reducing the harmful effects of chemical fertilizers and artificial growth regulators. Drought stress is one of the main limitations of food production around the world, and due to increasing population and water deficiency, there is a global attention for using some materials to increase resistant of plant to drought stress. Chemical stimulants are currently used for decreasing negative effects of water stress in plant. Now a days, use of natural materials, such as plant extract is recommended by researchers. Garlic extract is one of the natural extracts that contains many enzymes and more than 200 biochemical compounds that, due to its richness in minerals and plant hormones, causes cell enlargement, cell division and, plant growth. Humic acid is created from the decomposition of organic matter and is beneficial to plant growth and development. Therefore, the aims of this research were to study the effects of using natural substances of humic acid and garlic extract on nutrients uptake (NPK) and growth of wheat plant under drought stress.Materials and methodsThis study was performed during 2018 in a completely randomized design with factorial arrangement in three replications under greenhouse conditions. The studied soil with texture class of loam had pH = 8.11 and EC = 1.28 dS m-1. Experimental factors include drought stress at three levels of 95%, 65% and 45% of field capacity, garlic extract at three levels of foliar application of 0, 2% and 4% and humic acid at two levels of foliar application of 0 and 300 mg l-1. Drought stress were treated by the weight method, 17 days after sowing. Foliar application of humic acid (twice, 13 and 20 days after threating the drought stress) and garlic extract (three times, 18, 24 and 27 days after threating the drought stress) were performed by spraying 150 ml pot-1 of the solutions in each time. The plants were harvested 54 days after sowing and the parameters of shoot dry weight and uptake of nitrogen, phosphorus and potassium in plant were measured. Statistical analysis was done using SAS 9.4 software and the comparison of means was done using Tukey's test at the 5% probability level.Results and discussionThe results showed that foliar application of humic acid and garlic extract alone had a positive effect on dry weight and uptake of nitrogen and phosphorus of shoot. In addition, garlic extract also increased the potassium uptake. Drought stress reduced all investigated parameters; however, foliar application of garlic extract under drought stress conditions increased the absorption of nitrogen, phosphorus, and potassium. In 65% of field capacity, nitrogen uptake by using 2% garlic extract and phosphorus and potassium uptake by using 4% garlic extract had a maximum amount compared to others. In general, garlic extract, due to its antioxidant properties and the presence of growth-promoting compounds such as minerals, vitamins, phytohormones, sulfur compounds, enzymes and amino acids, can improve growth parameters and absorption of nutrients in wheat plant. Humic acid improved growth parameters due to its role in increasing cell membrane permeability, respiration and photosynthesis, phosphate absorption, root and cell expansion, and acting as hormone-like substances.ConclusionThe foliar application of wheat plant with garlic extract and humic acid as natural stimulants had a favorable effect on the plant growth and nutrients uptake. Garlic extract was more effective than humic acid in reducing the negative effects of drought stress. Finally, the use of natural materials such as garlic extract and some high consumption compounds such as humic acid can be an environment-friendly and safe approach to improve plant growth and to reduce the destructive effects of chemical fertilizers and synthetic growth regulators.
Physiology of crops under stress conditions
Farzaneh Amirikia; Majid Nabipour; Masoumeh Farzaneh
Abstract
IntroductionThe researchers have been forcing to investigate and find an edible alternative high forage quality plant that has a well-tolerated instinct against adverse environmental conditions. Alhagi, a genus of Fabaceae is one of the most important halophyte plants in the world, as an industrial forage ...
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IntroductionThe researchers have been forcing to investigate and find an edible alternative high forage quality plant that has a well-tolerated instinct against adverse environmental conditions. Alhagi, a genus of Fabaceae is one of the most important halophyte plants in the world, as an industrial forage product used in the near future, medicinal production and pharmaceutical use. There are many reasonable that Alhagi plants productivity and satisfactory yield requires good seed germination and seedling establishment. Generally, germination and seedling establishment is the most decisive stage of Alhagi plants life cycle to environmental stress. Moderate to severe salinity stress is main abiotic causes of Alhagi plants productivity loss at the seedling growth stage. High accumulation of Na+ and Cl- ions cause various negative influences that impact Alhagi production, such as delays in the response of the plant to environmental conditions, retardation of germination, growth and development, inhibition of enzymatic activities and accumulation of some compatible osmolyte. In addition, to the salinity stress, the seed germination, seedling establishment and total dry matter production in Alhagi plants occurs depends on a seed priming and type of species. However, few research studies have so far investigated the impact of different seed priming on the total dry matter production as well as some physiological responses in Alhagi species.Materials and methodsTwo separate experiments was conducted to investigate seed priming (non-priming, hydro priming, hormonal priming with 50 ppm gibberellin and hydro priming + hormonal priming with 50 ppm gibberellin) and different salinity levels (urban water source with EC=0.96 dS.m-1, 8 and 16 dS.m-1 using seawater Persian Gulf) on seed germination, dry matter and some physiological response of Alhagi species (Alhagi maurorum Esfahan ecotype and A. graecorum Khuzestan ecotype). The first experiment (seed germination) was carried on in the petri dish culture and second experiment (in the pot) at the field conditions was performed under split factorial experiments were conducted based on a randomized complete block design with four replications in Department of Plant Production and Genetics, Faculty of Agriculture, Shahid Chamran University (Ahwaz, Iran) during 2020-21. Meanwhile, during research, after calculating of the leaching fraction, EC of the root environment was controlled three times with an interval of one month by preparing a saturated extract from the pot bed and only in the third sampling was performed a leaching in the treatments of 16 dS m-1, with a salinity level lower than the studied treatment (8 ds.m-1).Results and discussionThe results showed a significant effect of salinity × priming × species interaction on all studied traits except for transpiration rate, Na and K content. In the case of transpiration rate, only the effects of salinity and priming were significant. Mean comparison results showed that the highest amount of seed germination, total dry matter, net photosynthesis rate, sub-stomata CO2 concentration, photosynthetic water use efficiency and number of leaves per plant in A. graecorum Khuzestan ecotype under Non-salinity stress and Hydro priming + Hormonal priming with 50 ppm gibberellin treatment (increased by 29.1, 1.52, 26.8, 98.7, 15.6 and 38.8 percent respectively compared to the Non-priming and Non-salinity stress treatment in the A. maurorum Esfahan ecotype). The highest level of mesophilic conductance was observed in A. graecorum Khuzestan ecotype under Non-priming and 8 dS.m-1 salinity stress treatment (with an average of 0.492 mmol CO2.m-2.s-1).ConclusionIn this experiment, results showed significant differences in total dry weight, net photosynthesis rate, transpiration rate, sub-stomata CO2 concentration, mesophyll conductance and photosynthetic water use efficiency between two Alhagi species at different salinity conditions using Persian Gulf water. Indeed, dry matter and photosynthesis traits in both Alhagi species responded negatively to increasing salinity levels and increasing of salinity up to, 8 dS m-1 induce the loss in physiological responses. Among the priming treatments, the hydro priming + hormonal priming with 50 ppm gibberellin showed a more favorable condition in the two Alhagi species in terms of the studied traits. Finally, in cultivation and development of Alhagi species for breeding programs in saline coastal lands and for the restoration of pastures, according to the results, A. graecorum Khuzestan ecotype under the combined treatment as hydro priming + hormonal priming with 50 ppm gibberellin, recommended for high production.
Physiology of crops under stress conditions
Ahmad Shadmehri; Hamid Abbasdokht
Abstract
IntroductionOne of the non-biological stresses for crop plants is drought and lack of water, which is the most important factor limiting the growth of crop plants in arid and semi-arid areas, including Iran. Drought impairs normal growth, disturbs water relations, and reduces water use efficiency in ...
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IntroductionOne of the non-biological stresses for crop plants is drought and lack of water, which is the most important factor limiting the growth of crop plants in arid and semi-arid areas, including Iran. Drought impairs normal growth, disturbs water relations, and reduces water use efficiency in plants. Plants, however, have a variety of physiological and biochemical responses at cellular and whole organism levels, making it a more complex phenomenon. The rate of photosynthesis is reduced mainly by stomatal closure, membrane damage, and disturbed activity of various enzymes, especially those involved in ATP synthesis. Plants display a range of mechanisms to withstand drought, such as reduced water loss by increased diffusive resistance, increased water uptake with prolific and deep root systems, and smaller and succulent leaves to reduce transpirational loss. Therefore, the effects of drought stress and seed nutritional priming on plants can play an important role in managing different irrigation regimes to deal with adverse environmental conditions and improve crop yield management.Materials and methodsQuinoa is one of the crops that has received special attention in recent years due to its high nutritional value and resistance to dehydration. For this purpose, an experiment was conducted in the form of a factorial split plot, with three rounds of irrigation of 7, 10 and 14 days as the main factor and seed priming at two levels without prime as a control and Iron sulfate + zinc sulfate combination as the second factor was applied on three genotypes (Q12, Q29 and Giza1) of quinoa as secondary factors, in the crop year of 2021-2022 in the regions of Neishabour and Kashmar.Results and discussionMoisture stress decreased the relative water content and percentage of membrane stability. In Kashmir region, the highest relative water content was observed in cultivars Q12 and Giza under the treatment of irrigation once every 14 days. While in the Neishabur region, the highest value of the mentioned variable was obtained in the treatment of irrigation once every 7 days and cultivar Q29. Slicing analysis of the interaction effect of cultivar and irrigation treatments and the interaction effect of irrigation and priming in Kashmir region showed that the 7 and 10 day irrigation treatment was significant on cell membrane stability. Comparison of the average interaction effect of the three tested factors in Neishabur area showed that the variety Q12 (regardless of seed priming) along with applying 14 days of irrigation caused a significant increase in membrane stability in Neishabur. Although the lowest level of membrane stability was obtained in the priming treatment of Q12 and Giza cultivars with the application of 7 days of irrigation once. It was observed that the priming treatment of Q29 and Giza cultivars with irrigation every 10 and 7 days, respectively, showed the highest amount of total chlorophyll in the Kashmir region, while in the Neishabur region, the highest amount of total chlorophyll was obtained in non-priming of Giza cultivar with the application of 10 Irrigation once a day. The results of the experiment showed that seed priming of Q12 and Q29 cultivars under irrigation once every 7 days caused a significant increase in seed yield in Kashmir region. In Neishabur region, the highest amount of seed yield was obtained in the non-priming cultivar Giza under irrigation once in 10 days.ConclusionIn general, seed priming with zinc sulfate and iron sulfate can improve the physiological characteristics of quinoa under water stress. Although in regarding the relative water content, the Q29 variety had a dominant effect on the priming treatment in Neishabour region. According to the results of the Q29 variety in the Kashmar region and the Giza variety In the Neishabour region, it will help plant growth by maintaining the chlorophyll content of the leaves under low irrigation conditions.
