Fereshteh Kamiab; Hamid Mohammadi
Abstract
Introduction: Narcissus is one of the most important ornamental plants in the world. The deficiency of microelements is a major problem limiting the production of ornamental plants under high-pH soils in most regions of Iran. Cu and Mn are essential microelements for the growth and development of plants ...
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Introduction: Narcissus is one of the most important ornamental plants in the world. The deficiency of microelements is a major problem limiting the production of ornamental plants under high-pH soils in most regions of Iran. Cu and Mn are essential microelements for the growth and development of plants as they are involved in many physiological reactions. Fe is involved in the synthesis of chlorophyll and many enzymes, respiration, and nucleic acid metabolism. Cu is a cofactor for numerous enzymes and is also involved in ethylene biosynthesis and activity, respiration, photosynthesis, regulatory proteins, cell membrane metabolism, and hormone signals. The deficiency of microelements, especially Fe, influences productive and reproductive growth of ornamental plants. Thus, this experiment aimed to evaluate the uptake rate of Cu and Mn nano-chelates and their effects on some morphological and physiological Characteristics of ‘jonquil’ narcissus.
Materials and Methods: This study was carried out in the research garden of Agriculture Faculty of Rafsanjan University in 2015 in factorial experiment based on randomized complete block design with two factors of Fe at four levels of 0, 1, 2 and 3 (g/l) and Cu at three levels of 0, 1 and 2 (g/l) in three replications. The weight of the cultivated bulbs were about 8-10 g. They were planted in eight rows spaced 20 cm with on-row spacing of five cm at the depth of 15 cm in each plot in August. According to soil analysis, 40 tons of manure and 100 tons of urea per ha were applied. The nano fertilizer was purchased from Nano-research Biozar Company. Foliar application was done three times: 1- when the plants had three leaves, 2- before flowering and 3- after flowering at 45-day intervals. Different parameters were recorded including plant height, number of leaves, width and length of leaves , number of main bulb, main bulb weight and diameter, , bulblet diameter and weight, flowering stem height and diameter, number of florets, florets diameter, fresh and dry weight of florets, flower vase life, Cu and Fe concentration, protein, chlorophyll and total soluble solids. Foliar spraying was done three times at the intervals of 45 days.
Results and Discussion: The results showed that the concentration of Cu and Fe in the leaves were enhanced with increase in the rate of each nano-chelate, implying high uptake rate of these nano-chelate by leaves in this plant. The application of Fe (2g/l) and Cu (0.5 g/l) resulted in the highest vegetative growth such as plant height, number of leaves, leaf width and length, number of main bulb, main bulb weight and diameter , and bulblet diameter and weight. High pH in experimental soil caused low absorption of micro elements in this condition. This deficiency was compensated with foliar application of nano-chelates and as a result, the Fe and Cu involved processes were improved in them. On the other hand, enhanced Fe and Cu concentrations in leaves could cause more photosynthesis and higher level of assimilation in plants. Likewise, these elements influence some enzymatic activity such as peroxidase, catalase and cytochrome oxidase; consequently, more vegetative growth was observed. Reproductive growth such as flowering stem height and diameter, number of florets, floret diameter and fresh and dry weight and flower vase life were improved in this experiment. The control of abiotic stress is one of the most important roles of Cu and also it is cofactor of superoxide dismutase that has been known as a free radical scavenger in plants that could increase quantitative and qualitative traits of flower. This treatment resulted in the highest amount of protein, chlorophyll and total soluble solids in the leaves of narcissus. Fe is one of the essential elements for chlorophyll synthesis. It also has an important role in activating nitrate reducates enzyme that uses ammonium to synthesize proteins. Cu is involved in the synthesis of proteins and enzymes that have major roles in such processes as respiration, photosynthesis, phenol metabolism, lignifications and ouxin regulation in plants. Thus, the results of this experiment showed that these nano-chelates were absorbed considerably by leaves of narcissus and they are suitable for foliar application. It should be noted that higher concentration of this fertilizer in this experiment has toxic effects. It is suggested that 2g/l Fe plus 0.5 g/l Cu were used to improve vegetative and reproductive growth of ‘jonquil’ narcissus, especially in high-pH soils.
