Ornamental plants
Ali Sahari Moghaddam; Behzad Kaviani; Ali Mohammadi Torkashvand; Vahid Abdossi; Ali Reza Eslami
Abstract
IntroductionYew or English yew (Taxus baccata L.) from the family of Taxaceae is an ornamental shrub that is used in various industries. Root induction and formation process at the base of stem cuttings of yew is slow. This species is in danger of extinction. Stimulation of rooting in cuttings causes ...
Read More
IntroductionYew or English yew (Taxus baccata L.) from the family of Taxaceae is an ornamental shrub that is used in various industries. Root induction and formation process at the base of stem cuttings of yew is slow. This species is in danger of extinction. Stimulation of rooting in cuttings causes the plant to grow faster. Polyamines are a group of plant growth regulators that play a variety of roles, including cellular differentiation and development and stimulation of adventitious root production. Some yew habitats have been destroyed because of neglect, destruction, livestock and ineffective exploitation. The yew is propagated by seeds or through cutting and grafting. Propagation of yew through seed is difficult and obtained plants show non-uniformity. Therefore, vegetative propagation is used to produce plants similar to the mother plant. The proliferation of the plant through leafy stem cutting is one of the most famous and the best propagation methods due to the preservation of the genetic structure and uniformity. Increasing the rooting capacity of trees and shrub cuttings is being carried out with a variety of plant growth regulators around the world. Putrescine has shown a better response in compare with other polyamines. The stimulation effect of exogenous application of polyamines, especially putrescine, was shown on the rooting of several plants’ cutting. Literature evaluation showed that there is not any study on the effect of polyamines on the rooting of the yew stem cuttings. Therefore, the aim of this research was to improve the rooting conditions of difficult-to-root cuttings with different concentrations of putrescine (a type of polyamine). Materials and MethodsIn order to investigate the effect of different concentrations of putrescine, an experiment was performed based on a completely randomized block design with 4 replications. Treatments included 0 (as a control), 500, 1000, 2000, 3000, 4000 and 5000 mg.l–1 of putrescine concentrations. In October, 25 cm of the end of the shoot of 5-years-old mother plants were cut and used as hardwood cuttings. The cuttings diameter was 2.5-3 mm. The lower ends of the shoot cuttings were kept at different concentrations of putrescine for 10 seconds and then placed in the cultivation bed. In this study, root percentage, number of roots, root length, stem length, shoot number, leaf number and survival percentage of cuttings were measured. Cuttings cultivation bed was perlite, cocopeat and peat moss. To prevent possible contamination, the bottom of the cuttings were immersed in a 2/1000 fungicide solution of Berdofix a week befor cutting preparation. Results and DiscussionThe results of analysis of variance showed that different concentrations of putrescine on all traits were significant at 1% probability levels. The results of mean comparison showed that the largest number of roots (6.50 per plantlet) and the highest root length (7.70 cm per plantlet) were observed in cuttings treated with 500 mg.l–1 putrescine. The highest number of shoots (5.50 per plantlet) and the highest rooting percentage (97.50) were obtained in cuttings treated with 2000 mg.l–1 of putrecine. The maximum number of leaves (41.25 per plantlet) was counted in cuttings treated with 3000 mg.l–1 of putrescine. Yew can be propagated successfully by stem cuttings. Natural conditions propagation and in vitro propagation beside cryopreservation are effective approaches to conserve plants particularly those putted in the red list. Plant growth regulators have an effective role in increasing the rooting of difficult-to-root cuttings of trees and shrubs. The exogenous use of polyamines as a new group of hormones stimulated root production in some cuttings. Peach × almond hybrid cuttings treated with 2 mM putrescine for 5 min showed the highest rooting percentage, root number and root length with the best quality. Putrescine is capable to influences on other plant growth regulators and has less toxicity than most of them. Polyamines stimulate cellular division in dissection place cells of cuttings such as cambium and phloem. The exogenous application of these compounds, especially putrescine during the root formation phase resulted in an increase in endogenous putrescine, endogenous auxin and peroxidase enzyme activity. In the cutting of the leafy stem of Corylus avellana L., the use of putrescine stimulated rooting. The study, like the present study, confirmed that putrescine can be useful for increasing rooting percentage and root quality. Putrescine had an effective role in the rooting of the stem cuttings. The present study revealed that the lowest root number was counted in cuttings that were not treated by putrescine (control). Polyamines (spermine, spermidine and putrescine) increased rooting percentage and root growth by stimulating root cell division (increased mitotic index of tip root cells) in regenerated pine (Pinus virginiana Mill.) seedlings. Polyamine biosynthesis and antioxidant enzymes activity were increased during root induction and formation. The exogenous application of spermidine in the apple (Malus prunifolia) stem cutting stimulated rooting by changing the concentration of some hormones. Spermidine regulated the expression of genes involved in the production of auxins. The study aimed to investigate the cellular-molecular effect of polyamines on the structure and development of roots in Arabidopsis showed that these organic compounds adjusted the size of the root meristematic zone during the effect on both symptomatic accumulations of hormones and reactive oxygen species (ROS). The same and different results are presented with the present findings by some other researchers. The main cause of these different results is the difference in the amount and balance of endogenous hormones, including polyamines in different species. Plant genotype, type of cuttings, cutting age, environmental factors, nutritional status especially type and amount of carbohydrates in the plant, the transfer rate of these carbohydrates from leaves to roots, the presence and the amount of phenolic compounds, nitrogen compounds, phonological stages and cutting season also play an effective role in these differences.
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 ...
Read More
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.
Rasul AbaszadehFaruji; Mahmood Shoor; Ali Tehranifar; Bahram Abedy; Nasim Safari
Abstract
Introduction: Ornamental plants play a vital role in meeting the mental and spiritual needs of peoplethat considered significance from commercial point of view as well. Optimal production of agricultural products requires suitable soil and adequate and absorbable nutrients for plant. Organic materials ...
Read More
Introduction: Ornamental plants play a vital role in meeting the mental and spiritual needs of peoplethat considered significance from commercial point of view as well. Optimal production of agricultural products requires suitable soil and adequate and absorbable nutrients for plant. Organic materials are important because ofimproving soil physical properties and soil fertility. Soil fertility depends on the content oforganic matter as well as the quality, quantity and dynamics of these materials insoil. Organic acids are an important source of organic matter. One of the most abundant forms of organic matter in nature is humic compounds which can be found in all soil and water environment. They play an important role in cation exchange, nutrients release, phosphorus buffering capacity and metal and toxic organic molecules maintenance.
Materials and Methods: In order to evaluate the effect of humic substances on morphological characteristics of geranium, thisexperiment was conducted in research greenhouse of Ferdowsi University of Mashhad during the years 2014 and 2015. The experiment was carried out as factorial based on completely randomized design with two factors and three replications. The first factor hadfour levels of humic acid (0, 0.2, 0.5 and 1 g/l), and the second hadfour levels of fulvic acid (0, 0.2, 0.5 and 1 g/ml). Treatment was usedalong with irrigation. Morphological characteristics included the number of leaves, number of nodes, number of branches, plant height, root length, leaf area, fresh weight of shoot, fresh weight of leaf, fresh weight of root, dry weight of shoot, dry weight of leaf, dry weight of root, volume of shoots, volume of root, fresh weight of shoot were measured at the end of the experiment. Statistical analysis of the results was performed by using Jmp-8 software. Charts were drawn using Excel 2010 and difference among treatments means were compared with LSD test.
Results and Discussion: The results of means comparison showed that combined use of humic acid and fulvic acid hadpositive effects on growth traits such as height, internode length, root length, fresh weight of shoot, fresh weight of root, fresh weight of leaf, dry weight of shoot, dry weight of leaf, volume of shoot, volume of root and leaf area. Research had shown that the application of humic fertilizers increased nitrogen content in shoots of the plant. It wasreported that nitrogen compounds existed in humic acid are important factors affecting the growth of plants. Humic acid also increasedshoot growth by increasing the uptake of nitrogen, calcium, phosphorus, potassium, manganese, zinc, iron and copper as well as hormone-like properties. It wasalso found that humic acid enhancedplant growth by increasing the activity of the RuBisCO enzyme and the subsequent increase in photosynthetic activity. Furthermore, humic acid reduced the pH of alkaline soils and causedthe nitrogen to be absorbed to a greater extent. The use of humic substances increased the leaf area and thus photosynthesis, therefore leading to the production of more dry matter in plants. Humic fertilizers also had a significant effect on root growth. Researchers had suggested that the presence of oxygen groups in humic acid increased lateral root growth. Although humic acid increased the growth of both root and shoot, its effectiveness on the root system wasmore evident.
Conclusions: This experiment was conducted with the aims of evaluating the effect of humic organic fertilizers, reducing the harmful effects of chemical fertilizers and improving the quality of plant growth in geranium. According to the results obtained from the present research, it can be concluded that combined application of humic acid and fulvic acid had greater effects on the majority of traits compared to the sole application of aforementioned compounds.
