Research Article
Mina Ghazaeian; Gholamhossein Davarynejad; Kamal Ghasemi Bezdi; Seyyed Hossein Nemati
Abstract
Introduction: The walnut family (Juglandaceae) consists of approximately 60 species of deciduous trees is native of the American continents, Europe, and Asia. Pecan (Carya illinoensis) is belonged to the Juglandaceae family and is one of the most valuable nut products all over the world. Embryo culture ...
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Introduction: The walnut family (Juglandaceae) consists of approximately 60 species of deciduous trees is native of the American continents, Europe, and Asia. Pecan (Carya illinoensis) is belonged to the Juglandaceae family and is one of the most valuable nut products all over the world. Embryo culture techniques for plant breeding as well as basic studies in physiology and biochemistry are widely used. The low percentage of germination and the long propagation cycle and the need for stratification treatments from three to six months are the most important barriers to the development of high yielding cultivars through hybridization. Plant regeneration methods from embryo culture in vitro allows overcoming the barriers of hybridization, as well as obtaining higher and faster multiplication rate of plants of an elite genotype.
Materials and Methods: In this experiment, an adapted native genotype of pecan in Gorgan city, Golestan province, Iran was selected. The mature fruits were harvested after five months of pollination. They were immediately transferred to the laboratory. For cold pretreatment, nuts packed in a paper bag and stored in 4-5ºC for 15 days. The effect of two types of culture medium, growth regulators and seed pretreatment (15 days at 4-5 °C) on germination of mature embryos of pecan has been determined. Murashige and Skoog (MS) and Woody Plant Medium (WPM) and IBA (0 and 1 mgl-1), BAP (0, 1 and 2 mgl-1) and GA3 (0 and 1 mgl-1) media were used to embryo rescue evaluation. The data obtained were statistically analyzed in completely randomized block design (RCBD). Each treatment was replicated at least third, and each replicate consisted of two zygotic embryos. Means of germination period, percent of seed germination, root and shoot length and leaf number in different media and various PGRs combination were compared based on LSD at p ≤0.05.
Results and Discussion: The results showed, although cold pretreatment for 15 days had no effect on germination period, root length and number of leave but also, effect on germination percentage and shoot length. There are some different hypothesis about the effect of cold pretreatment on embryo germination between researchers. Some researchers believed that, there is low efficiency in embryo germination in lack of cold pretreatment and GA3. Cold pretreatment or GA3 reduce the ABA level and promote embryos germination. The others reported poor germination for somatic embryos when they treated with GA3 and cold pretreatments. Pearce et al. (1987) reported that GA3 and substrate of GA3 can be increased during the chilling process as ABA levels decrease. Furthermore, application of exogenous GA3 induces germination. Tang et al. (2000) reported that somatic embryos germination poorly happened in cold condition and addition of GA3 did not change the poor germination. Kaur et al. (2006) and Peyghamzadeh and Kazemitabar (2010), reported that the embryo germination in Juglans regia L. was higher when GA3 and cold pretreatments were simultaneously applied as compared to those when applied separately. In this experiment, media has no effect on embryo germination period but, could effect on other parameters. As the results showed, MS media showed the maximum percentage of germination, root and shoot length and number of leave in both condition (with and without cold pretreatment). In this experiment root length of germinated pecan embryo was higher in MS medium. Mapelli et al. (2001) reported that seed germination resulted in marked changes in the metabolism of free amino acids in walnut cotyledons. About 52% of the total free amino acids in one-month-old seedlings was present in the cotyledons and about 26% was in the taproot. The concentration of free amino acids in the taproot was similar to that in the embryonic axis, and greater than that in the cotyledons. T11 (1mg/l-1 IBA, 1mg/l-1BAP and 1mg/l-1 GA3) and T12 (1mg/l-1 IBA, 2mg/l-1BAP and 1mg/l-1 GA3) treatments were the highest in germination percentages in both treatment (with and without cold pretreatment). There was no significant differences between 1 mgl-1 and 2 mgl-1 of BAP.
Conclusion: Pecan as like walnut, is considered to be one of the most recalcitrant species in vitro. It is necessary to determine the optimal culture conditions to establish it for shortening time in seed propagation. This seedling could be applied as primary material for breeding programs, grafting and physiology study. The best growth of micro plant achieved in MS medium with 1 mgl-1IBA, 1 mgl-1GA3 and 2 mgl-1BAP.
Research Article
H. Eini Garsadafi; B. Zahedi; Fatemeh Moradipour
Abstract
Introduction: Today in order to produce vegetable fruits tolerant to adverse environmental conditions and increase growth, yield and fruit quality, grafting methods have been created. Tomato (Solanum lycopersicum) is one of the most important greenhouse products. Heirloom tomato cultivars lack disease ...
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Introduction: Today in order to produce vegetable fruits tolerant to adverse environmental conditions and increase growth, yield and fruit quality, grafting methods have been created. Tomato (Solanum lycopersicum) is one of the most important greenhouse products. Heirloom tomato cultivars lack disease genetic resistance and are particularly susceptible to epidemics in the field. Grafting can be used to unite the soil borne disease resistance and enhanced vigor of hybrid tomato cultivars with the high fruit quality of heirloom cultivars. There are deficiencies in vegetable grafting including skills for grafting operation performance and after the grafting, having enough knowledge to select rootstock, farm management in application of required fertilizers, graft incompatibility, excessive vegetative growth of grafting plant and physiological abnormalities, and fruit quality reduction. For grafting herbaceous plants such as vegetables, depending on the type of plant, plant size, grafting purpose, available equipment, preference and experience of the grafting plant producer and post-grafting management, different grafting methods have been introduce which is for different species and the used method is completely different. Each method has its own advantages and disadvantages, which are effective in the survival and development of grafting plants. This experiment was conducted in order to evaluate the effect of grafting methods on yield and vegetative growth of tomato plants.
Material and Methods: Three common grafting methods, splice, cleft and approach grafting were evaluated for tomato "SV 8320" cultivar grafted on "Rimac" rootstock. Executive operations were conducted in a completely randomized design with three replications at greenhouse of Lorestan Agriculture Faculty. Plant height, number of auxiliary shoot, number and length of internodes, number of fruit cluster, number of flower in cluster, root fresh and dry weight, number of fruit cluster, number of fruit in cluster, width and diameter of fruit, fruit weight, fruit fresh and dry weight, length of fruit tail, fruit tissue firmness, total soluble solid, pH, diameters of hypocotyl, pre, middle and total yield , ratio of the marketable fruits to second degree fruits, and fruit tissue firmness were recorded. Data was analyzed using SPSS software and means were compared by Duncan’s multiple range test.
Results and Discussion: Grafting method had significantly effect on plant height, number and length of internode, root fresh and dry weight, number of fruit cluster, width and diameter of fruit, fruit weight, fruit fresh and dry weight, length of fruit tail, fruit tissue firmness, pH, pre, middle and total yield, the ratio of the marketable fruits to second degree fruits at 5% of probability level. Vegetative characteristics and yield in grafted plants were higher compared to non-grafted plants.
Conclusion: According to results of this experiment using different grafting methods lead to stimulate growth in grafting plants, increasing production and product quality. Changes caused by the rootstock are controlled through water absorption, synthesis and transition of water, minerals and herbal hormones. Signal generation in the rootstocks and transition of them to the scion, causes changes in the physiology and morphology of the grafted plant. Grafting success varied between grafting methods, so that splice grafting is better than other methods. Graft compatibility was shown by the ability of tissue to regenerate and the vessels ability in wound tissues to rejoint together then grow and develop as a vigorous composite plant. Attempts to increase the productivity of grafted plant should be followed by the application of good agricultural practices.
Research Article
Mohsen Moradi; Farhang Razavi; Vali Rabiei; Morteza Soleimani Aghdam; Leila Salehi
Abstract
Introduction: In recent years, γ-aminobutyric acid (GABA), a non-proteinogenic four-carbon signaling amino acid, has been employed as a safe strategy for attenuating chilling injury and fungal decay, delaying senescence and keeping sensory and nutritional quality of fruits and vegetables during postharvest ...
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Introduction: In recent years, γ-aminobutyric acid (GABA), a non-proteinogenic four-carbon signaling amino acid, has been employed as a safe strategy for attenuating chilling injury and fungal decay, delaying senescence and keeping sensory and nutritional quality of fruits and vegetables during postharvest life. In addition to applying GABA as exogenous safe procedure, heightening cellular GABA shunt pathway activity also is pivotal for attenuating chilling injury and fungal decay, delaying senescence and keeping sensory and nutritional quality of fruits and vegetables during postharvest life. Low temperature storage is widely employed for prolonging postharvest life of fruits and vegetables accompanying by keeping sensory and nutritional quality. Tomato is one of the most important horticultural crops, which exhibits higher benefits for human health but being endemic to subtropical climates, they are very vulnerable to chilling injury. Cold storage application is normally employed as a regular low-cost real postharvest technology. Owing to its great socio-economic significance, great efforts have been done by researchers to attenuating chilling injury in tomato fruits during low temperature storage employing safe strategies such as melatonin, brassinosteroids, salicylic acid, nitric oxide, and gibberellic acid. Attenuating chilling injury in tomato fruits by postharvest treatments may attribute to keeping safe membrane integrity representing by lower electrolyte leakage and malondialdehyde (MDA) accumulation occurring by eliciting endogenous polyamines, proline and nitric oxide accumulation by activating CBF1 signaling pathway, hampering phospholipase D (PLD) and lipoxygenase (LOX) enzymes activity, activating reactive oxygen species (ROS) scavenging enzymes activity resulting in higher ascorbic acid and glutathione accumulation, maintaining endogenous GA3 homeostasis occurring by higher CBF1 signaling pathway concurrent with higher endogenous salicylic acid accumulation, which not only are pivotal for conferring chilling tolerance in tomato fruits but also are crucial for preserving sensory and nutritional quality.
Material and Methods: Tomato fruits (Solanum lycopersicum cv. Izmir) were picked at the mature green stage in Zanjan Province, Iran, and transported to the fruit analysis laboratory at Zanjan University. In the laboratory, the fruit was screened for uniform size, maturity, and absence of mechanical damage. Fruits (1440) were divided into four groups, each consisting of 360 fruits. The experiment was done in triplicate in which each replicate consisted of 120 fruits. The exogenous GABA applying was done by immersing of fruits in GABA at 0, 0.1, 1, and 5 mM for 15 min at 20 ˚C. Then, fruits were air dried at room temperature and stored at 4 ± 0.5 ºC (85–90 % RH) for 28 days. After assessment of chilling injury every 7 days during storage at 4 ˚C followed by shelf life at 25 ºC for 3 days, biochemical analyses were performed.
Results and Discussion: In recent experiment, we showed that the exogenous GABA applying, especially at 5 mM, is beneficial for attenuating chilling injury in tomato fruits during storage at 4 ºC for 28 days which was associated with higher membrane integrity representing by lower electrolyte leakage and malondialdehyde (MDA) accumulation. Keeping safe membrane integrity in tomato fruits in response to exogenous GABA applying may ascribe to triggering reactive oxygen species (ROS) scavenging catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX) enzymes activity giving rise to higher endogenous ascorbic acid accumulation concomitant with promoting phenylpropanoid pathway activity representing by higher phenylalanine ammonia lyase (PAL) enzyme activity giving rise to higher phenols and flavonoids accumulation and superior DPPH scavenging capacity.
Conclusion: Therefore, exogenous application of GABA not only is proficient for attenuating chilling injury but also is beneficial for preserving nutritional quality of tomato fruits during storage at 4 ºC for 28 days.
Research Article
Ali Imani; Khosro Parvizi; Hamdollah Beyrami jam; Ebrahim Hadavi
Abstract
Introduction: Iron chlorosilicon caused by calcium carbonate can be controlled widely with iron chelate in nutrition management of gardens, but it has high costs and potential environmental hazards. Such constraints have led to alternative strategies for managing iron nutrition in relation to soil and ...
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Introduction: Iron chlorosilicon caused by calcium carbonate can be controlled widely with iron chelate in nutrition management of gardens, but it has high costs and potential environmental hazards. Such constraints have led to alternative strategies for managing iron nutrition in relation to soil and plant parameters. Almond rootstocks and almond x peach hybrids (GF 677) are widely used as the rootstock for almonds, peaches and nectarines in the Mediterranean basin, moreover, in addition to its drought resistance, has a high tolerance to iron chlorosis. Different references of almond tree have introduced this fruit tree as a chlorosis resistant, but it shows different ranges of chlorosis when grafted on almond x peach hybrids such as GF677 and GN15. Therefore, this study carried out to evaluate the effect of calcium bicarbonate on some physiological characteristics of selected almond cultivars on the GN15 rootstock.
Materials and Methods: This research was conducted during 2015 and 2016 to evaluate the resistance to bicarbonate and the amount of chlorosis produced in selected almond cultivars on the hybrid rootstock (peach and almond) as a factorial experiment with completely randomized design with three replications in greenhouse conditions. The first factor consisted of different concentrations of calcium bicarbonate (0, 20, 10, 30 and 40 mmol L-1) and the second factor included nine selected almond cultivars grafted to the GN15 rootstock and a GN15 (non-grafted) rootstock. Almond cultivars included 9 cultivars including Supernova, 25-1, 40-13, Mamaei, 16-1, Kaghazi, Sahand, 200A, 7-9, and GN15 rootstock. Each plot included a pot, where the rootstock planted. In the spring, the cultivars and GN15 rootstock planted in plastic pots with soil compositions including perlite (50%) and cocopeat (50%). After sufficient growth of these rootstocks in the pots, almond cultivars were grafted onto them and immediately after the transplantation, the calcium bicarbonate treatments began after proper growth of the scions. In order to apply bicarbonate treatment, 1.62, 3.23, 4.86 and 6.48 g L-1 calcium bicarbonate (Ca (HCo3) 2) were added to the pots. In addition, 10% of calcium bicarbonate added also to the pots because of the deficiency of 10% chemical purity. After applying the treatments, chlorophyll, chlorophyll a and b, carotenoids, chlorophyll fluorescence were measured in two stages at intervals of 30 and 90 days. After the end of the growth period, the length and diameter of the current season branches and the leaf length and width of each almond cultivar were measured and recorded in different treatments. Two-way ANOVA of the data was carried out using SAS software (v. 8.02, SAS Institute, Cary, NC) and the means were compared based on Duncan’s multiple range test.
Results and Discussion: Based on the ANOVA results, it was determined that the effects of calcium bicarbonate, cultivar and their interactions on the content of chlorophyll a and b were statistically significant (p≤0.01). The lowest decrease levels of chlorophyll a and b were found in the leaflets of Kaghazi, Mamaei, saplings, 25-1, and 40-13 cultivars, but the highest decrease was observed in Supernova cultivar, 7-9, and GN15. The reasons for decreasing the chlorophyll content of the leaf with the increase of bicarbonate levels can be related to iron deficiency and its deactivation and the role of iron in the synthesis of chlorophyll. Nevertheless, the difference for chlorophyll depletion at different levels of bicarbonate in different cultivars can be due to the capacity of these cultivars to tolerate higher levels of bicarbonate and the possibility of the synthesis of chloroplastic proteins in leaf cells even with a relative lack of iron. In all cultivars, as well as the GN15 rootstock, the level of carotenoids decreased with increasing concentrations of calcium bicarbonate. However, the response of the cultivars was different. Under bicarbonate conditions, reducing leaf iron concentration reduces chlorophyll and carotenoids. The results of the mean comparison showed that bicarbonate induced height growth reduction and branch diameter in the current season, while the reaction of the studied rootstocks were also different. So that the highest decrease in growth rate was observed in Supernova, 7-9 cultivars and GN15 rootstock and the lowest decrease of growth rate were found in the cultivars of Kaghazi, 1.25-1 and -40-13. High concentrations of bicarbonate, by disabling and decreasing iron absorption, indirectly reduces DNA synthesis, cell division, and thus decreases cell growth and plant biomass. The results of this study are in agreement with Ghasemi et al. (2010) in different responses of the rootstock to bicarbonate concentration on the height and diameter decreasing of current season branch. Mean comparison of data showed that the length and width of leaf area in all studied cultivars decreased with increasing concentration of calcium bicarbonate in irrigation water. Also, leaf length and width decrease in rootstock grafted cultivars had a significant difference, so that the lowest reduction in leaf length and width was in pepper, midwifery and 25-1, and the highest leaf area decrease in Supernova cultivars, 7-9 and GN15 base was observed. Leaf growth decreases in calcareous soils due to a decrease for iron in the symplast. The specific effects of high bicarbonate on leaf growth in almond cultivars and the different reaction of almond rootstocks in this study are in agreement with Tedaion et al. (2004) results in orange, as well as Wahom et al. (2001) in olive and peach.
Conclusion: Totally, the results of this study indicate that cultivar and rootstock cause the amount of chlorosis tolerance induced by calcium bicarbonate. In general, in terms of morphological and physiological traits studied in this research, Kaghazi and 25-1 cultivars are the most tolerant, while 7-9 and supernova are the most sensitive cultivars to bicarbonate.
Research Article
Mahtab Salehi; Ramezan Kalvandi
Abstract
Introduction: Medicinal plants are rich sources of the main active substances in many drugs. Although the production of secondary metabolites is controlled by genes, their production are considerably influenced by environmental conditions, so that environmental factors cause changes in the growth of ...
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Introduction: Medicinal plants are rich sources of the main active substances in many drugs. Although the production of secondary metabolites is controlled by genes, their production are considerably influenced by environmental conditions, so that environmental factors cause changes in the growth of medicinal plants as well as the amount of active substances. In different habitats, physiological, morphological and genetically variations are seen in populations of species. These variations are created in response to contrasting environmental conditions. Studies of population in many plant species regarding to the pattern of variation have showed the occurrence of localized populations which adapted to the particular ecological conditions of their habitat. Iran as a center of diversity of Stachys houses about 35 species. The majority of species prefers alpine and subalpine habitats and grows under various ecological conditions in habitats like rocky places, mountain steppes, and stream banks or sometimes in forests. S. inflata Benth. is a medicinal plant from Lamiaceae family which is used extensively in folk and traditional remedies to treat infection, asthma, rheumatism and other inflammatory diseases.
Materials and Methods: This study was conducted to evaluate the morphological and phytochemical diversity of seven populations of S. inflata Benth. from different districts of Hamedan province in 2017. Traits such as plant height, stem diameter, leaf length and width, fresh and dry weight of floral branch, inflorescence length, fresh and dry weight of flower, essential oil percentage and phenol and flavonoid content were measured. In order to investigate physical and chemical properties of soil, soil samples were collected from a depth of 30 cm. Then they were transferred to the soil laboratory. Plants samples were collected in flowering stage and were dried in 25-30 °C. They were stored in envelopes in 22±3 °C away from the sun. For extracting essential oil, 50 gr of shoots were milled and then mixed with distilled water. This process lasted for three hours. Main components of essential oil were identified and determined by gas chromatography. The grouping of populations based on morphological and phytochemical traits was done by cluster analysis. The correlation between the elevations of studied areas above the sea level and soil properties was also done by Pearson method.
Results and Disscution: The results showed that the highest essential oil content was related to Avarzaman, Aznaveleh and Koohani populations (0.2%) and the lowest amount was obtained from Asadabad (0.11%). Although 22 compounds were identified in the essential oil, there was a great deal of variation in the percentage and type of components of the essential oil in the studied populations. The main components of essential oil were Spathulenol (26.25%), Octanol acetate (14.03%), Germacrene D (13.96%), Incensole acetate (13.41%), Bicyclogermacrene (10.66%) and Phytol (9.52%). Avarzaman population had the highest total phenol (141.9 mg GAE/gr) and flavonoid content (109.4 mg routine/gr) and the lowest content of phenol (86.9 mg GAE/gr) and flavonoid (68.8 mg routine/gr) was related to Asadabad and Koohani populations respectively. Avarzaman had the highest plant height (47.2 cm) and was significantly differed with other populations. The highest dry weight of floral branches (1.16 mm) was related to Asadabad population that was not significantly differed with Aznaveleh and Avarzaman population and the lowest dry weight of floral branch (0.57 mm) was observed in Koohani population. There was a significant negative correlation (-0.86) between the height of the studied habitats and the level of phosphorus in these areas. According to the morphological traits dendrogram analysis, seven studied populations were divided into two main groups. The populations of Avarzaman, Ekbatan, Ghazi Khan, Aznaveleh and Asadabad were in group A and Koohani and Gammasiab populations were in group B. Based on phytochemical traits dendrogram analysis, the populations of Ekbatan, Ghazi Khan, Asadabad, Koohani and Gammasiab were in group A and Avarzaman population was in group B.
Conclusion: In this study, the highest amount of essential oil content was obtained from populations which were collected from areas with the lowest elevation above the sea level. The soil of these areas had more phosphorous content. Therefore, the environmental factors as well as genetic factors have contributed in creating diversity in morphological and phytochemical characteristics of this plant.
Research Article
Seyyedeh Mahdiyeh Kharrazi; Ahmad Sharifi; Saba Nejatizadeh; Azadeh Khadem; Maryam Moradian
Abstract
Introduction: Considering the occurrence of successive droughts in our country and the necessity of optimal water consumption, the use of modern technologies such as closed systems to increase the efficiency of fertilizer and water use will have an effective role in reducing production costs and increasing ...
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Introduction: Considering the occurrence of successive droughts in our country and the necessity of optimal water consumption, the use of modern technologies such as closed systems to increase the efficiency of fertilizer and water use will have an effective role in reducing production costs and increasing yield. The Nutrient Film Technique (NFT) system is one of the hydroponic culture systems in which the nutrient solution is circulated continuously. In this system, a thin layer of nutrient solution will be available to the plant roots, which has a significant effect on reducing fertilizer and water consumption.
Materials and Methods: The present study was conducted to select an optimal system for cultivation of Gerbera plantlets. Plantlets were cultivated in different systems after the acclimation stage: Integrated bedding system as a closed system containing different culture media (Perlite, vermiculite, vermiculite: perlite, cocopeat: perlite and rock wool) and NFT hydroponic system as a closed system. For fertilization, the following fertilizer combination (mM) was used: K2SO4 (0.22), KNO3 (3.62), KH2PO4 (0.71), NH4H2PO4 (0.35), NH4NO3 (0.53), Ca (NO3)2,4H2O (1.48), MgSO4, 7H2O (0.4), MnCl2, 4H2O (0.0049), H3BO3 (0.020), ZnSO4 (0.0061), CuSO4, 5H2O (0.00048), NaMoO4, 2H2O (0.00058), FeSO4, 7H2O (0.0348), Na2EDTA (0.0384). The experiment was conducted in a completely randomized design with six treatments in six replicates. During six months, the growth parameters of the plants including number of leaves, petiole length, fresh and dry shoot weight, leaf chlorosis percentage, leaf necrosis percentage, flower number, flower diameter, flowering stem height, number of days to flowering, end diameter of the stalk and the middle diameter of the stalk were evaluated. Data preparation was done in Excel and data analysis was performed using the Jump 8 software. Mean comparison between treatments was performed with LSD test at 5% probability level and charts were drawn using the Excel program.
Results and Discussion: The results showed that there was a significant difference between treatments for the number of leaves (p <0.01). Seedlings cultivated in the vermiculite culture medium produced the highest number of leaves; however, there was no significant difference between seedlings cultured in vermiculite and vermiculite: perlite media. The lowest number of produced leaves was observed in plantlets grown in the NFT system. Also, the seedlings grown in the rock wool medium had no significant difference with the NFT system. In this regard, the drought stress on plants and the consequent poor growth of plantlets reduced the number of produced leaves. The percentage of necrotic leaves in the NFT system was more than twice the vermiculite culture medium. There was no significant difference between cocopeat: perlite, perlite, rock wool, and NFT systems. Also, the lowest amount of necrotic leaves was found in the vermiculite culture medium, which did not have a significant difference with vermiculite: perlite culture medium. Low levels of leaf necrosis in these treatments indicate the optimal absorption of nutrients and the proper growth of plantlets in these culture media. The results showed that plantlets cultivated in the vermiculite and vermiculite: perlite flowered more quickly than other culture media and also produced more flowers. Plantlets grown in the rock wool medium did not show the desirable performance, which is due to drought stress. Besides, the use of cocopeat in the culture medium did not have a beneficial effect on plants. Measuring the initial electrical conductivity in the cocopeat culture medium also indicates a high EC concentration in this culture medium, which could affect the growth parameters of the plant and lead to poor vegetative growth of plantlets. Since Gerbera plant has bulky roots, the roots of this plant cannot be developed well in the NFT system, so the use of the NFT system is not suitable for Gerbera cultivation. The best performance of plant samples was obtained from vermiculite culture media, but since there were no significant differences between vermiculite and vermiculite: perlite, so to reduce production costs, the use of vermiculite: perlite culture medium in the closed system is recommended for the cultivation of Gerbera plant.
Conclusion: Since Gerbera plant has bulky roots, the roots of this plant cannot be developed well in the NFT system, so the use of the NFT system is not suitable for Gerbera cultivation. The best performance of plant samples was obtained from vermiculite culture media, but since there were no significant differences between vermiculite and vermiculite: perlite, so to reduce production costs, the use of vermiculite: perlite culture medium in the closed system is recommended for the cultivation of Gerbera plant.
Research Article
Maryam Zare Hasan Abadi; Ali Ganjeali; Mehrdad Lahouti; Nasrin Moshtaghi
Abstract
Introduction: Agrobacterium rhizogenes hairy roots induction is used for secondary metabolite production in plants. A. rhizogenes is a genus of gram-negative soil bacteria belonging to the Rhizobiaceae family that causes hairy roots at the site of infection. Hairy roots have various advantages, including ...
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Introduction: Agrobacterium rhizogenes hairy roots induction is used for secondary metabolite production in plants. A. rhizogenes is a genus of gram-negative soil bacteria belonging to the Rhizobiaceae family that causes hairy roots at the site of infection. Hairy roots have various advantages, including high growth rate, more genetic stability than the callus and suspension cultures, growing well on hormone-free media that have been reported effective for producing high levels of secondary metabolites. Basil (Ocimum basilicum) is a popular herb with important economical applications in food, cosmetic, and pharmaceutical industry. It is a digestive stimulant with anticarcinogenic, antibacterial, and anticonvulsant properties. The main phenolics reported in basil plants are in the classes of phenolic acids and flavonoids, some of which have human health benefits. This study was designed to develop hairy root culture from O. basilicum using different of A. rhizogenes strains for the production of total phenols and introduce the best strain of A. rhizogenes to induce hairy root and growth and production of total phenol.
Materials and Methods: Different A. rhizogenes strains (ATCC-15834, A4, MSU, and R1000) were studied to investigate their effects for the transformation and production of secondary metabolites in O. basilicum. Therefore, shoot and leaf explants and nodes of the seedlings were used for Agrobacterium-mediated transformation. These explants were inoculated with four A. rhizogenes strains and transferred to ½ MS medium. About four weeks after cultivation with A. rhizogenes, hairy roots were excised from the seedlings and subcultured to fresh medium MS liquid culture containing 500 mg/l cefotaxime. After 60 days of inoculation, various parameters, including dry weight, infection percentage, number of hairy roots per explant, and total phenol contents were measured. The growth rate and phenolic contents of the transformed hairy roots were compared with normal ones. Total genomic DNA was isolated from non-transgenic and transgenic hairy root lines using the Cetyl Trimethyl Ammonium Bromide (CTAB) method. Isolated genomic DNA was used to detect the rolC gene through polymerase chain reaction (PCR) analysis. The PCR using specific primers for rolC of T-DNA and virD2 was used to confirm the nature of resulted transgenic hairy roots.
Results and Discussion: Selecting efficient A. rhizogenes strains, as well as the type of explants, are crucial factors for hairy root induction. All used A. rhizogenes strains were able to produce hairy roots. Hairy roots appeared on the nodes at the point of injection, but were not forming on the shoot and leaf explants. So, the choice of the plant material is crucial for successful transformation with A. rhizogenes and usually, transformation of young tissues gives the best results. The transgenic status of the hairy roots was confirmed using PCR with rolC and virD specific forward and reverse primers. All lines showed the presence of 612 bp rolC amplified products, indicating the integration of T-DNA of A. rhizogenes and O. basilicum. Hairy roots could synthesize phenolic compounds, which was significantly higher in hairy roots than non-transformed control. Four hairy root lines were independently evaluated for their content and these lines showed variation in total phenolic contents, with the highest amount (312 mgGAE/ g DW) in hairy roots induced by ATCC-15834 strain and the lowest amount (113.2 mgGAE/ g DW) in hairy roots induced by R1000 strain. The results showed that the strain ATCC-15834 caused the highest infection percentage (68.1%) along with the highest number of hairy roots (4.8) per explant and root length (1.8 cm). The growth rate and phenolics production were investigated in each hairy root of O. basilicum from infection by four different A. rhizogenes strains. The highest growth rate (103.2 mg DW) and production of total phenol (312 mg/g DW) were found in ATCC-15834. The growth rate of transformed hairy roots was more than that of normal ones.Total phenol contents in all hairy roots were also increased significantly compared with non-transformed control plants (4.6 times in hairy roots induced by A. rhizogenes strain ATCC-15834). ATCC-15834 has been reported as the most widely used A. rhizogenes strain owing to its strong induction ability, and the variation in hairy root induction could be due to disparity in the virulence of different A. rhizogenes strains.
Conclusion: The hairy roots of O. basilicum had shown promising results in terms of significant yield of phenolic contents and had the potential for being scaled-up further for phenol production. It could be concluded that A. rhizogenes strains had different abilities in hairy roots induction. Therefore, the selection of an effective A. rhizogenes strain for the production of transformed root cultures is important, highly dependent on the plant species, and must be determined in future experiments.
Research Article
Faraj Moayedi; Sajad Kordi; Ali Ashraf Mehrabi; Soheila Dastborhan
Abstract
Introduction: Sweet basil (Ocimum basilicum L.) is one of the oldest spices belongs to the Lamiaceae family. It is a herbaceous annual plant, which is native to subtropical regions of Asia, Africa, America. Basil is an important economic crop and widely used in the culinary arts, food processing and ...
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Introduction: Sweet basil (Ocimum basilicum L.) is one of the oldest spices belongs to the Lamiaceae family. It is a herbaceous annual plant, which is native to subtropical regions of Asia, Africa, America. Basil is an important economic crop and widely used in the culinary arts, food processing and pharmaceutical industries. Nitrogen is one of the most important nutrients for plant production that plays a major role in photosynthetic activities and crop yield capacity and its availability affects plants growth and biochemical processes. Nitrogen deficiency is often a limiting factor in vegetable production such as sweet basil. Nitrogen usage significantly can be increased the herb yield of basil grown in different environmental conditions. The nutritional and environmental factors are the most important factors for growth of the medicinal plants. In the present research, changes in yield, nitrate content, essential oil yield and some physiological traits have been investigated in four cultivars of sweet basil under different levels of nitrogen.
Materials and Methods: A field experiment was carried out in the Agricultural Research Station of Khorramabad during 2016 growing season. The experimental factors were arranged as a factorial-split-plot in time experiment based on randomized complete blocks design with three replications. Experimental factors were cultivars of sweet basil (O.basilicum var Italian Large Leaf، O. basilicum var Mobarakeh, O. basilicum var Sweet Thai and O. basilicum var Cinnamon) and nitrogen fertilizer (0, 100 and 200 kg ha-1 urea) assigned to the main plots as factorial and different cuttings (three harvests from each plot) considered as sub-plots. The half amount of nitrogen (as urea; 46% N) was distributed in experimental plots before planting the seeds and the rest used after the first harvest. Seeds of sweet basil were planted at May, 25th 2016 as five rows with 2m length and each main plot area was 5 m2. The space between rows was 50 cm. All plots were irrigated immediately after sowing. Subsequent irrigations were carried out every four days. The control of weeds conducted manually during the experiment time. The sweet basil plants were harvested three times in early flowering stage in July 12, August 15 and September 25. Samples of 1 m length were taken from the center of two rows located in the middle of each plot. Plants were cut from above ground and transferred to the lab for measuring total dry yield. The measured traits in this study included branches per plant, inflorescences per plant, plant height, leaf percentage, total dry yield, essential oil yield, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and nitrate content. SAS (version 9.1) and MSTAT-C statistical software were used to conduct analysis of variance (ANOVA) and comparison of means, respectively. The Duncan's multiple range test, at 5% probability level, was used to rank the differences among means.
Results and Discussion: The results indicated that the application of nitrogen fertilizer significantly improved all the studied traits. The highest and the lowest essential oil yield belonged to 100 kg ha-1 urea and control, respectively. Nitrogen fertilizer by providing the nitrogen needed for the basil plant during the growing season provides a favorable environment for the production of further biomass. Total dry weight of the all basil cultivars increased with application of nitrogen fertilizer in all harvests. The highest total dry weight and nitrate concentrations were achieved by Italian largel cultivar with application of 200 kg ha-1 urea in the second harvest. The increment in total dry weight of basil by application of nitrogen fertilizer could be attributed to the increment in chlorophyll content and better growth of plants and subsequently the better canopy development which ultimately leads to the better usage of solar irradiance, higher photosynthesis and finally higher dry weight in basil plants. Application of nitrogen chemical fertilizer could increase essential oil yield of sweet basil, mainly due to the increasing of total dry weight.
Among basil cultivars, Italian large leaf cultivar had the highest leaf percentage and essential oil yield compared to the other cultivars. The lowest number of branches per plant, number of inflorescences per plant, leaf percentage, essential oil yield and total chlorophyll belonged to Mobarakeh cultivar. All the evaluated parameters were lower than the first harvest except leaf percentage and chlorophyll content.
Conclusion: According to the results, application of nitrogen fertilizer had a positive effect on growth, and consequently led to increase the plant vegetative yield. Due to the fact that in terms of more of the studied traits there was no significant difference between application of 100 and 200 kg ha-1 urea fertilizer and also reduce the consumption of chemical fertilizers generating pollution, Italian large leaf cultivar and application of 100 kg ha-1 urea are recommended to access an acceptable growth and quantitative and qualitative yield in sweet basil under the environmental conditions similar to Khorramabad.
Research Article
Hassan Farhadi; Mohammad Mehdi Sharifani; Mehdi Alizadeh; Hossein Hokmabadi; Sasan Aliniaeifard
Abstract
Introduction: Agriculture of Iran is known worldwide for its pistachio (Pistacia vera L.) and is one of the most important non-oil exports. Therefore, attempts to improve the yield can be one of the primary goals in the pistachio industry in Iran. Due to the drought problem in Iran, increasing the cultivation ...
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Introduction: Agriculture of Iran is known worldwide for its pistachio (Pistacia vera L.) and is one of the most important non-oil exports. Therefore, attempts to improve the yield can be one of the primary goals in the pistachio industry in Iran. Due to the drought problem in Iran, increasing the cultivation area to increase production may not be a good option. Therefore, the purpose of this study was to compare the drought tolerance of different pistachio seedlings from open pollination and pollinated with domestic species pollen and controlled crosses using integerrima pollen in order to find the most tolerant genotypes.
Materials and Methods:
The first step: Controlled pollination and hybrid seed production In order to produce hybrid seeds, a controlled pollination using integerrima pollen grains at Razavi Pistachio Research Institute was conducted for five cultivars; Ahmad Aghaei, Akbari, Sorkheh Hosseini, Garmeh and Fandoghi. Each replication had a tree and from each tree, seven branches were selected that had at least three to four flower buds and four branches from it for controlled pollination, two branches for open pollination and a branch was considered for negative control. Before the flower clusters were fully opened, 70% alcohol was sprayed on the branches to prevent the possibility of unwanted pollen. In order to ensure controlled pollination, in the bud swelling stage, the branches were isolated by double-layered bags measuring 30 × 45 cm. Pollen was collected from the Arzooieh area of Kerman province to select the male parent of integerrima. Then, a combination of flour and integerrima pollen (1:1 ratio) was injected into the insulating bags and pollination was performed. In late summer, hybrid seeds were harvested.
The second stage: Drought resistance test of hybrids obtained from first step The experiment was conducted as factorial based on a Completely Randomized Design with four replications at the research greenhouse located in Gorgan University of Agricultural Sciences and Natural Resources during 2019-2020. The treatments were consisted of ten pistachio genotypes; Ahmad Aghaei, Akbari, Sorkheh Hosseini, Garmeh, Fandoghi and (hybrids between integerrima as the pollinizer and genotypes of Ahmad Aghaie, Akbari, Sorkheh Hosseini, Garmeh and Fandoghi were applied as the maternal parent and three levels of drought including control (field capacity), mild stress (65% of field capacity) and severe stress (30% of field capacity) were applied on 3 months old seedlings for 84 days. Seeds obtained from free and controlled pollination were planted in pots with a diameter of 33 cm and a height of 35 cm on April 6, 2017. Three seeds were planted in each experimental unit, and after planting and ensuring establishment, the number of plants in the pot was reduced to the final level of one in each pot. Each replication was consisted of four experimental units or four pots, and each pot was contained a plant. At the end of the experiment, growth and physiological parameters were measured. Statistical analysis of the results was performed using SAS 9.1 software.
Results and Discussion: Results of statistical analysis showed drought stress had a significant effect on leaf number, stem length, root length, leaf relative water content, electrolyte leakage, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid, and leaf and root proline content. With increasing drought levels, all traits except root length, electrolyte leakage and proline content were reduced in comparison with control. Sorkheh Hosseini × integerrima, Ahmad Aghaei × integerrima, Akbari × integerrima interactions and genotypes of fandoghi and fandoghi × integerrima interaction were superior in the most of traits by drought, respectively. Based on the results it seems hybrids of Sorkhe Hosseini × integerrima, Ahmad Aghaei × integerrima and Akbari× integerrima crosses will be used as genotypes with dry-tolerant genes to modify cultivars in arid regions.
Research Article
Mahboobeh Jalali; Negin Salehi Chegeni
Abstract
Introduction: High nitrate (NO3−) in vegetables, especially in leafy vegetables poses threaten to human health. Selenium (Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human ...
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Introduction: High nitrate (NO3−) in vegetables, especially in leafy vegetables poses threaten to human health. Selenium (Se) is an important element for maintaining human health, and exogenous Se application during vegetable and crop production is an effective way to prevent Se deficiency in human bodies. Exogenous Se shows a positive function on plant growth and nutrition uptake under abiotic and biotic stresses. However, the influence of exogenous Se on NO3− accumulation in hydroponic leafy vegetables is still not clear.
Materials and Methods: The present study was conducted in a completely randomized design with four replications at Research Greenhouse of Lorestan University. In this study, hydroponic lettuce (Lactuca sativa L. var. Grin leek) and spinach (Spinacia oleracea L. var. Sirius) plants were subjected to six different concentrations (0, 0.1, 0.5, 5, 10 and 50 μmol L–1) of Se as Na2SeO3. Zero concentration was considered as control. The modified Hoagland nutrient solution were prepared and 8 liters was added to each pot. The nutrient solutions were replaced with fresh solution every five days throughout this experiment. After the emergence of new roots in the nutrient solution, treatment was applied and selenium was added to the pots at a specific concentration. After Se treatment for 40 days, three plants were randomly harvested from each treatment. The effects of Se on plant growth, NO3− content, activities of nitrogen metabolism enzymes, photosynthetic capacity and glutathione peroxidase enzyme activity of lettuce (Lactuca sativa L.) and spinach (Spinacia oleracea L.) were investigated. The second youngest, fully expanded leaf was used to monitor photosynthetic capacity using chlorophyll meter and portable photosynthetic apparatus, respectively. Nitrate concentration in dried samples was determined based on nitrate to nitrite reductions in the vicinity of zinc powder and hydrogen ion. Data preparation was done in the Excel program and data analysis was done using SPSS 16 software. The means comparison of the treatments was done by LSD test and finally, the figures were drawn using MS Excel.
Results and Discussion: The results showed that the lowest and highest biomass in both plants were observed in 50 and 5 μmol L–1 Se treatments, respectively. Different levels of selenium had no significant effect on root fresh weight in spinach. However, in the lettuce, at 50 μmol L–1, the root fresh weight significantly decreased compared to the 5 μmol L–1. Moreover, exogenous Se positively decreased NO3− content and this effect was concentration-dependent. The lowest NO3− content was obtained under 5 μmol L–1 Se treatment.NO3− content in lettuce was lower than that of spinach in all treatments. The application of Se enhanced photosynthetic capacity by increasing the stomatal conductance, photosynthesis rate and chlorophyll content of plants. No significant difference (p ≤0.05) was observed in spinach in chlorophyll, stomatal conductance and photosynthetic rate between 10 and 5 μmol L–1, however, in lettuce this difference was significant. Chlorophyll content in lettuce was higher than spinach in all treatments. The best concentration for photosynthetic capacity in both plants was five μmol L–1, which could explain similar changes in root and shoot dry weight in the different treatments. The results showed that low selenium concentrations (≤5 μmol L–1) stimulated NO3− assimilation by enhancing nitrate reductase (NR), nitrite reductase (NiR) and glutamine synthetase (GS) activities. The lowest nitrate reductase activity in lettuce and spinach was 50 μmol L–1 and control, respectively. In all treatments, nitrate reductase activity in lettuce was higher than in spinach. The reaction of nitrate reductase to selenium application was similar to nitrate reductase activity. Glutamine synthetase activity in both plants increased with increasing selenium concentration. However, as the concentration increased (≥ 5 μmol L–1), the activity of this enzyme began to decrease. In addition, the activity of this enzyme was higher than control in all treatments. Selenium also increased glutathione peroxidase concentration. A significant increase in glutathione peroxidase activity at five μmol L–1 was observed compared to the other treatments in lettuce. However, there was no significant difference in the activity of this enzyme in spinach at concentrations of 5 and 0.5 μmol L–1.
Conclusion: These results provided direct evidence that exogenous Se showed positive function on decreasing NO3− accumulation via enhancing activities of nitrogen metabolism enzyme in both plants. This study suggested that five μmol L–1 Se could be used to reduce NO3− content and increased hydroponic lettuce and spinach yield.
Research Article
Fatemeh Ghorbanalizade; Mahnaz Karimi; Kamran Ghasemi; Mehrnaz Hatami
Abstract
Introduction: Water hyacinth (Eichornia crassipes) is one of the world’s most prevalent invasive aquatic plants. Due to the environmental and economic concerns associated with the water hyacinth spread, control of this plant seems will be necessary. Composting is promising techniques for controlling ...
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Introduction: Water hyacinth (Eichornia crassipes) is one of the world’s most prevalent invasive aquatic plants. Due to the environmental and economic concerns associated with the water hyacinth spread, control of this plant seems will be necessary. Composting is promising techniques for controlling water hyacinth. Humic acid is the fraction of naturally occurring organic materials, which derive from the decomposition of plant and animal residues. Humic acid plays important roles in plants through stimulation of root growth and increase of water and nutrient uptake by plants. In this study, we evaluated the effect of water hyacinth compost and humic acid on the vegetative and reproductive characteristics of gerbera flowers
Materials and Methods: The present study was conducted as a factorial experiment in a completely randomized design with three replications. The first factor was water hyacinth compost (0, 25, 50, 75 and 100% v/v) and the second factor was humic acid (0, 250 and 500 mg L-1). The peat moss + perlite (2:1 v/v) was considered as a control treatment. To prepare water hyacinth compost, the water hyacinth was collected from a river in Sari, Mazandaran, Iran. Water hyacinth leaves were exposed to direct sunlight for eight hours to wither then chopped to fine pieces and eventually was spread on the surface. The thickness of leaves is five-centimeter. One centimeter thickness of animal manure was added on top of the water hyacinth leaves and then a layer of ash and lime respectively added. This step was repeated until the height of the layer reached to one meter, finally the top layer was covered with dry leaves of native trees and black polyethylene sheets. The mass was mixed up every 15 days to get a better result (uniform decomposition). Finally, after three months, the compost was prepared. Gerbera (cv. Artist) seedlings with uniform size (15 cm) were planted in plastic pots at different levels of compost. Humic acid was used once every ten days. The average day and night temperature in the greenhouse during the experiment was 17±2 and 23±2ºC, respectively, and the average greenhouse humidity was 65 to 75%. Flowering time, number of flowers, number of leaves, stem length, flower stem diameter, flower disk diameter, fresh and dry weight of shoots and roots, phenol content, total chlorophyll and carotenoids, concentrations of nitrogen, phosphorus, potassium and calcium in the leaves, ion leakage of petals and vase life were evaluated.
Result and Discussion: According to the results of the effect of compost, humic acid and their interaction on most of the studied characteristics were significant. The highest number of flowers with 117% increase compared to the control treatment was related to 50% compost + 500 mg L-1 humic acid. In this treatment, the time of flower emergence occurred 40 days earlier than the control. The highest chlorophyll content with 155.52% increase compared to control was observed in 25% compost + 500% humic acid. Mineral elements in the leaf of the Gerbera plant were significantly affected by growth media and humic acid. The highest nitrogen content was found in 50% compost + 500 mg L-1 humic acid (a 50% increase compared to control). The highest potassium content was observed in 50% compost + 250 mg L-1 humic acid. The highest concentrations of calcium were found in the leaves of plants grown in 50% compost + 500 mg L-1 humic acid. The highest vase life with a 71.67% increase compared to the control treatment was related to plants that were grown in 25% or 50% compost+ 500 mg L-1 humic acid. The lowest ion leakage was recorded in 50% compost + 500% humic acid with 56.79% decrease compared to the control. In the present study, most of the growth media and humic acid significantly affected most of the Gerbera plant parameters. The best results were obtained from 25% and 50% compost +250, 500 mg L-1 humic acid. Due to proper drainage, increased water retention, a pseudo hormonal compound such as auxin and increased absorption of elements, compost improve the chemical and physical structure of growing media. Also, high leaf nitrogen content was observed in most compost-containing substrates. This element plays a key role in vegetative growth. The concentration of nitrogen and phosphorus in compost is usually 5 to 11 times higher than soil which is gradually delivered to the plant and increases the growth and flowering of the plant. Humic acid plays important roles in plants through stimulation of root growth and increase of water and nutrient uptake by plants. In our study the application of humic acid at 250 and 500 mg L-1 significantly increased concentration of nitrogen, phosphorus, calcium and potassium as compared with control. It has also been reported that humic acid provides growth regulators to regulate and control hormone levels in plants and stimulates the production of plant enzymes and hormones, which ultimately increases the vegetative and reproductive growth of the plant.
Conclusion: The results of this study showed that water hyacinth compost with humic acid due to improving the root environment and increasing the absorption of nutrients, increased quantitative, qualitative and vase life characteristics of Gerbera in comparison with control (peat + perlite). 50% compost was introduced as the best treatment in combination with concentrations of 250 and 500 mg L-1 of humic acid.
Research Article
Zeinab Izadi; Abdolhossein Rezaei nejad
Abstract
Introduction: While Iron (Fe) is the fourth most abundant element in the earth’s crust, it is not easily available for plant roots. Therefore, Fe deficiency is one of the major limiting factors for plant growth and development in calcareous soils worldwide. Fe deficiency are also predominant in many ...
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Introduction: While Iron (Fe) is the fourth most abundant element in the earth’s crust, it is not easily available for plant roots. Therefore, Fe deficiency is one of the major limiting factors for plant growth and development in calcareous soils worldwide. Fe deficiency are also predominant in many areas of Iran. It is an essential micronutrient for plants that play vital roles in many metabolic processes. Fe is a component of a number of molecules such as Fe-sulfur (Fe-S) and heme Fe proteins, which are required for photosynthesis, respiration and N2 fixation. However, the possibility of using split-type fertilization at different growth stages during development has been explored in other plant species for macronutrients N, P, and K. The aim of this work was to test the hypothesis that it may be feasible to decrease Fe-chelate inputs, by studying the effect of gradually increasing of Fe concentration during Calendula officinalis growing period.
Materials and Methods: In order to study the effect of gradual increase of Fe concentration during Calendula officinalis growing period, an experiment was carried out as a completely randomized design with four replications (pots) at research greenhouse of Faculty of Agriculture, Lorestan University, in 2017. Treatments contained three levels of Fe (Fe-chelate Fe (III)- Ethylenediamine-N, N' –bis ((2-hydroxyphenyl) acetic acid): 4, 20 µM and staircase method. Staircasetreatment included increase of Fe concentration, so that at first week plants received 4 µM Fe then 2 µM was added to Fe concentration weekly, to reach 26 µM. Some morphological, physiological parameters, flower characteristics and gas exchange had measured. Data of all measured parameters were subjected to analysis of variance using the SAS software (9.1.3, SAS Institute Inc.), and means were compared using a Duncan test at P≤ 0.05.
Results and Discussion: Results showed that the application of 4 µM Fe led to higher root volume, and peroxidase activity. Romera et al. (2011) reported that under Fe deficiency, strategy of plants developed morphological changes in their roots and up-regulated the expression of Fe acquisition genes. Under Fe deficiency some phytohormones such as ethylene and auxin will increased. Both hormones play pivotal role in the development of sub-apical root hair and transfer cells. Sepahvand et al (2017) investigated the effect of ascorbic acid on pelagonium graveolens characteristics under Fe deficiency and found that peroxidase activity increased under Fe deficiency. Application of ascorbic acid led to decrease peroxidase activity. Maximum biomass was obtained in plants under 35 µM Fe and staircase treatment. Maximum chl a and b, chl a+b, carotenoids, root dry weight, flower diameter, flower longevity, number of flowers, and first flower fresh weight was observed in the plants under staircase treatment. Fe plays important role in biosynthetic pathway of chlorophyll and carotenoids. In addition, plants under staircase treatment showed the maximum photosynthesis and transpiration rate. Kong et al. (2014), reported that Fe deficiency led to decrease of δ- aminolevulinic acid and protochlorophyllide as precursors of chlorophyll. Ethylene and ABA are involved in Fe-deficiency signalling in plants, and these compounds may hasten senescence (Satoh, 2011). The short flower lifetime found in the present experiment in the low Fe treatment may be due to the boost in ethylene and ABA synthesis in response to Fe deficiency. On the other hand, plants under staircase regime had higher photosynthetic pigments that led to maximum photosynthesis. Increasing flower quality, quantity and longevity related to higher photosynthesis activity. Iron is a component of a number of proteins and enzymes, such as iron-sulfur (Fe-S) proteins and non-heme iron proteins, which are required during photosynthesis (Chakraborty et al., 2012). Li et al. (2016) investigated the influence and interaction of Cadmium (Cd) and Fe on photosynthesis and reported that Cd inhibits photosynthesis activity, but Fe alleviates the Cd-induced changes in photosynthesis activity. In addition, higher MDA contents were observed in plants under 35 µM Fe and staircase treatment. Li et al. (2012) reported that the high levels of Fe led to maximum MDA contents.
Conclusion: Growing the plants with staircase treatment increased flower yield, quality and longevity. These parameters are the most important factors in growing of ornamentals plants. Whereas Fe fertilizers are so expensive, restricting the use of expensive products such as Fe (III)-chelates at some growth stages can contribute to decrease the cultivation costs and minimize environmental pollution associated to an excess of fertilizer inputs. Therefore, gradually increasing Fe concentrations during production of Calendula officinalis under soilless culture would be recommended.
