Medicinal Plants
Mehdi Moradi; Bahram Abedi; Hossein Arouiee; Sasan Aliniaeifard; Kamal Ghasemi Bezdi
Abstract
Background and objectives
Light is the main environmental factor for plant growth and development. Different attributes of light such as intensity, quality and duration affect plant growth and productivity. Light spectrum of growing environment is a determinant factor for plant growth ...
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Background and objectives
Light is the main environmental factor for plant growth and development. Different attributes of light such as intensity, quality and duration affect plant growth and productivity. Light spectrum of growing environment is a determinant factor for plant growth and photosynthesis. The photosynthetic reactions are directly affected by various light parameters including its spectrum and intensity. Photosystem I and II (PSI and PSII) in the electron transport chain of photosynthetic apparatus are involved in converting solar energy to chemical compounds in plants. It has been found that the PSII is sensitive to light quality. Using The OJIP test, we can investigate the efficiency of various biological phases of the electron transport system. Light sources such as metal-halide, fluorescent, high-pressure sodium, neon lamps and light-emitting diode (LED) can be used for production of plants in closed environments instead of sunlight. Manipulation of the light spectrum of the lamps could trigger potential benefits by enhancing plant growth. Nowadays, by using the LED technology, it is possible to study the physiological effect of different light spectra for optimization of growth conditions and for increase the production of plants in controlled environments. This research was conducted to investigate photosynthetic apparatus, growth parameters, stomatal characteristics, transpiration rate and essential oil content of Salvia officinalis under different light spectra.
Materials and Methods
In this study, the effects of different light spectra were implemented and performed as a pot experiment using soilless media in the plant growth chamber based on a completely randomized design with 6 lighting spectra including White, Blue, Red and three combinations of R and B lights (R30:B70, R50:B50 and R70:B30) with three replications. The light intensity in all growth chambers was adjusted to photosynthetic photon flux density (PPFD) of 250 ±10 μmol m-2s-1 and light spectrum were monitored using a sekonic light meter (Sekonic C-7000, Japan). Growth condition was set at 14/10 h day/night cycles, 25/22oC day/night temperatures and 40% relative humidity. Three month following plant growth under different light spectra, the plants were evaluated for their growth parameters, stomatal characteristics (stomatal length, stomatal width, pore length or aperture) transpiration rate (E), relative water content (RWC), photosynthetic apparatus (evaluation of OJIP) and essential oil content. Data analysis of variance (ANOVA) was performed using IBM SAS software (Version 9.1) and the differences between means were assessed using Duncan’s multiple range tests at p≤ 0.05.
Results
The results showed that the stomata characteristics, photosynthetic performance, growth characteristics and essential oil content of Salvia officinalis were affected by different light spectra. Increasing the ratio of red light especially combined Red and Blue lights (R70:B30) led to the improvement of growth characteristics. Transient induction of chlorophyll fluorescence showed that the highest fluorescence intensities at all OJIP steps were detected in Red light. The lowest Fv/F0 and Fv/Fm were obtained in plants grown under Red light. Occurrence of leaf epinasty and decrease in Fv/Fm indicative of phenomenon of red light syndrome in the plants under Red treatment. Red light caused a reduction in performance index per absorbed light efficiency of (PIABS) and increase in quantum energy dissipation (ΦD0), light absorption (ABS/RC) and electron trapping (TR0/RC) per reaction center. The highest Fv/F0, Fv/Fm and PIABS were obtained under combination of Red and Rlue light. The highest ΦE0 was also detected in combination of Red and Blue light. The narrow and large stomatal apertures were detected under Red and Blue light, respectively. The highest transpiration rate was achieved in plants grown under Blue light LED. Increasing the ratio of Red light resulted in reduction in transpiration rate and improvement of leaf capacity to control water loss via reducing the opening of stomata. The highest amount of essential oil (1/75% v/w) was achieved in plants exposed to combination of Red:Blue light spectra (R70:B30).
Conclusion
light spectrum during plant growth can change plant metabolism, LED can be used in favor of producing good-quality food in controlled environment agriculture due to their ease of application, waveband manipulation and limited heat production. Our result showed that photosynthetic apparatus, growth parameters, stomatal characteristics, transpiration rate, relative water content and essential oil content of plants were considerably influenced by light spectra. Using OJIP test confirmed that plants grown under monochromatic Red and Blue lights were less efficient to successfully transfer the excitons and most of the absorbed energy by the photosystems was dissipated as heat. In conclusion, combined Red and Blue lights (especially R70:B30) caused favorable growth, photosynthetic functionality and maximum essential oil content of Salvia officinalis. Therefore, combination of R and B lights (R70:B30) should be considered for production of Salvia officinalis under artificial light systems during commercial controlled environment production of plants.
Medicinal Plants
Mehdi Moradi; Hossein Nastari Nasrabadi; Kamal Ghasemi Bezdi
Abstract
Introduction The Genus Thymus is one of the most important genera of the Lamiaceae family. According to Jalas (1971), Thymus is divided into eight sections: Micantes, Mastichina, Piperella, Teucrioides, Pseudothymbra, Thymus, Hyphodromi, and Serpyllum. About 18 species exist in some areas of Iran ...
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Introduction The Genus Thymus is one of the most important genera of the Lamiaceae family. According to Jalas (1971), Thymus is divided into eight sections: Micantes, Mastichina, Piperella, Teucrioides, Pseudothymbra, Thymus, Hyphodromi, and Serpyllum. About 18 species exist in some areas of Iran and most of them belong to Serpyllum Section and kotschiani Subsection. Chromosomal information is an important key for taxonomy, phylogeny, evolution, genetics and breeding in thyme. Therefore, this work was carried out to study the cytogenetic characteristics of genus Thymus belonging to the Subsection Kotschyani for breeding purposes and taxonomy.Materials and MethodsSeeds were collected from 5 wild populations and germinated on wet filter paper at 20 oC. One cm long roots were pretreated with 8-hydroxyquinolin and then washed in distilled water and fixed in carnoy solution for 24 hours. Hydrochloric acid (1N) was applied for 7 min to hydrolyze the roots. Staining was done by orcein for 24 h at room temperature. Stained roots squashed in one drop of 45% acetic acid and examined by a ZEISS Axiophot compound microscope. Cells in metaphase stage were photographed with a D450; Canon Inc. Japan digital camera. Ten well prepared metaphasic cells were selected and some chromosomal characteristics such as total chromosomal length (TL), long arm length (L), short arm length (S), the arm ratio (AR) [LA/SA], and centromeric index (CI), were measured using Micro Measure ver. 3.3 software. The following karyological parameters were determined: total chromosome form (TF%), intrachromosomal asymmetry index (A1) and interchromosomal asymmetry index (A2). Karyotypic characteristics have been determined using the symmetry classes of Stebbins (SC). Karyotype formula was determined from chromosome morphology based on centromere position in accordance with the classification of Levan.Results and Discussion This study reports the chromosome number and meiotic behavior of 31 populations belonging to 8 species of Thymus Subsect. kotschyani from Iran. In most species of this subsection, the base number of chromosome x = 15 and two diploid and tetraploid ploidy levels with chromosome number of 2n = 30 and 60 were observed. Only in T. migricus species, the base number of chromosome x = 14 was reported with two levels of diploid and tetraploid ploidy and chromosome numbers of 2n= 28 and 56. The chromosomes were mostly metacentric (m) or sub-metacentric (sm) in all species Among the various species with basic number of x= 15, the highest percentage of TF and the lowest amount of A1 were observed in populations belonging to T. eriocalyx (T7) indicating that this species has the most symmetric karyotypes. The lowest percentage of TF and the highest amount of A1 are in population of T. lancifolious (27) and T. fedtschenkoi (T28) species; this shows that the species has the most asymmetric karyotype among the species of this subsection. The highest amount of A2 was observed in T. eriocalyx (T7) species, indicated the asymmetry between chromosomes and chromosomal length. The difference in the number of chromosomes, ploidy levels and karyotype asymmetry in the populations and different species may be related to different environmental conditions in their habitat, pollination system (cross pollination) or polyploidy (Aneuploidy) in this genus.Conclusion The results showed that basic chromosome number in most species is 15 (x= 15). Two ploidy levels (diploid and tetraploid) were observed among different species. Chromosomes in most species, were metacentric and sub-metacentric. Based on intra- chromosomal symmetry (A1 and TF) T. eriocalyx species (T7) has the most symmetric and most primitive karyotype and the species T. lancifolius (T27) and T. fedtschenkoi (T28) have the most complete and the most asymmetric karyotypes. Also based on inter- chromosomal symmetry, (A2) T. eriocalyx (T) species has the most asymmetric karyotype.
Mehdi Moradi; Hamid Reza Roosta; Ahmad Estaji
Abstract
Introduction: Iron is an essential element for plant growth which is involved in many plant processes such as photosynthesis and activating enzymes involved in mitochondrial and photosynthetic electron transfer. Iron (Fe) deficiency is a common disorder affecting plants in many areas of the world, and ...
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Introduction: Iron is an essential element for plant growth which is involved in many plant processes such as photosynthesis and activating enzymes involved in mitochondrial and photosynthetic electron transfer. Iron (Fe) deficiency is a common disorder affecting plants in many areas of the world, and is chiefly associated with high pH, calcareous soils. Plant Fe deficiency has economic significance, because crop quality and yields can be severely compromised. Deficiency or low activity of iron in the plant causes chlorophyll is not produced in sufficient quantities and the leaves are pale. The decrease of chlorophyll leading to the reduction of the plant food processor and finally the yield is reduced. Iron fertilizers are grouped into three main classes: inorganic Fe compounds (soluble ones such as FeSO4·7HO), synthetic Fe chelates [such as ethylenediamine tetraacetic acid (EDTA) and ethylenediamine-di (o-hydroxyphenylacetic acid) (EDDHA)] and natural Fe-complexes (humates and amino acids). Iron could be applied in different chemical forms, including chelates and inorganic Fe salts. To our knowledge, no published data for tomato growing under hydroponic conditions have assessed the effects of application methods and different sources of Fe Fertilizer on plant yields, growth and nutritional condition. Therefore, this work was carried out to study the effect of FeSO4, Fe-EDTA, Fe-EDDHA and Fe-DTPA as a foliar spray and root-applied on the growth, yield, physiological characteristics of tomato plants under hydroponic system. Material and Methods: Regarding to the role of application methods and Fe sources on the absorption of this element and the process of photosynthesis and plant growth, a factorial experiment was carried out to determine the best methods of application (add to nutrient solution and foliar spray) and iron fertilizer (FeSO4, Fe-EDTA, Fe-DTPA and Fe-EDDHA) for growth and physiological characteristics of tomato in hydroponic system with three replications. Analysis of variance (ANOVA) was performed using the SAS program. If ANOVA determined that the effects of the treatments were significant (P ≤0.01 for F-test), then the treatment means were separated by Tukey range test. Result and Discussion: The results indicated that the plant height, dry and fresh weight affected by the application methods and iron fertilizer, so that the maximum and minimum plant height, and dry and fresh weight were obtained in application of Fe-EDTA to nutrient solution and foliar application of FeSO4, respectively. Mohammadipour et al., (2013) reported that by applying nano-chelate fertilizer of iron, iron sulfate, Fe-EDTA and Fe-EDDHA by two methods of foliar application and root-applied (soil) of Spathiphyllum plant, a significant difference between the types of fertilizer and application method were used. So that the maximum height and dry weight of the plant were obtained in Fe-EDDHA fertilizer treatment to the root application. The root and leaf Fe concentration affected by source of iron and the method of application so Fe-EDTA added to nutrient solution and foliar application had the highest amount of Fe in the root and leaf, respectively. Cu, Mn, Zn and some macro elements such as; Mg and P also influenced by the type of fertilizer and method of application. Roosta and hamidpour (2013) showed that the foliar application of Fe-EDDHA under aquaponic and hydroponic conditions increased the amount of K, Mg, Fe and decreased the concentration of Zn, Cu and Mn compared to the control treatment in tomato plants. Current experiment results showed that the maximum chlorophyll content (a, b and total) and maximal quantum yield of PS II photochemistry (Fv/Fm) and performance index (Pi) values of young and old leaves were found with Fe-EDTA in nutrition solution and the highest carotenoids and sugar soluble content were found in FeSO4 in nutrient solution and foliar application, respectively. Roosta and Mohsenian (2012) reported that there was also a linear relationship between leaf-Fe and chlorophyll content in pepper. The application of inorganic Fe salt (FeSO4) and Fe-chelates (Fe-EDDHA and Fe-EDTA) on pepper plants increased Chl a content in leaves of these plants compared to the control. Additionally, several investigations have described the beneficial effects of foliar Fe. Iron deficiency caused a significant reduction in the amount of chlorophyll a, b, total and carotenoids of pea (Iturbe-Ormaetxe et l., 1995). Conclusion: Based on the results, Fe-EDTA and Fe-EDDHA had the highest significant effect on vegetative growth of tomato, respectively. Thus, at neutral pH of nutrient solution as occurred in this experiment, application of Fe-EDTA in nutrition solution is suitable than the other source of iron fertilizer for tomato growth.
