Improvement and breeding
J. Gheshlaghpour; R. Khademian; B. Asghari; B. Sedaghati
Abstract
To evaluate the silicon effects on morphological characteristics as well as the percentage and composition of basil (Ocimum basilicum L.) essential oil under cadmium stress, a factorial greenhouse experiment was conducted in a completely randomized design. The treatments included cadmium metal (Cd) as ...
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To evaluate the silicon effects on morphological characteristics as well as the percentage and composition of basil (Ocimum basilicum L.) essential oil under cadmium stress, a factorial greenhouse experiment was conducted in a completely randomized design. The treatments included cadmium metal (Cd) as the first factor at three levels of 0, 25, and 50 mg kg-1 soil and silicon (Si) as the second factor with concentrations of 0, 1, and 2 mM. The characteristics including root length, fresh and dry weight of roots, plant height, fresh and dry weight of stems, stem diameter, number of leaves, fresh weight of leaves, number of buds, number of sub-stems, and percentage and composition of essential oil were evaluated. The results showed that Cd had negative effects on all studied morphological characteristics and significantly decreased their values compared to the control. However, Si treatment improved all these traits and with increasing the concentration of this element, a significant increase in the values of these traits was observed. Application of Si in the concentration of 2 mM caused 63.8, 81, 61, and 61% increase in the number of sub-stems, root fresh weight, stem fresh weight, and number of buds compared to the control, respectively. The amounts of five major constituents of basil essential oil including 1,8-cineole, linalool, estragole, methyl eugenol, and eugenol were affected significantly with the Cd and Si treatments. However, the interaction of these two treatments showed a significant effect only on the three compounds 1,8-cineole, linalool, and methyl eugenol. The maximum amounts of 1,8-cineole (5.06%) and methyl eugenol (6.21%) were observed in the plants which simultaneously exposed to the highest concentrations of Cd and Si. The amount of linalool was also decreased with the presence of Cd and increased with the Si treatment. The Cd treatment increased the amount of estragole by 12.8% and decreased the amount of eugenol by 25.2%. The Si treatment also increased the amount of estragole by 23.9% and decreased the amount of eugenol by 18.3%.
H. Fatemi; B. Esmaielpour; A.A Soltani-Toolarood; A. Nematolah Zadeh
Abstract
Silicon (Si) is the second most abundant element in the earth crust. Silicon has been shown to ameliorate the adverse effects of heavy metals on plants. This research was aimed to investigate the effects of silicon nano-fertilizer nutrition on growth and physiological characteristics of coriander (Coriandrum ...
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Silicon (Si) is the second most abundant element in the earth crust. Silicon has been shown to ameliorate the adverse effects of heavy metals on plants. This research was aimed to investigate the effects of silicon nano-fertilizer nutrition on growth and physiological characteristics of coriander (Coriandrum sativum L.) under lead stress. The study was conducted in a factorial experiment based on a completely randomized design with four replications in the research greenhouse of Mohaghegh Ardabili University during 2016. Experimental treatments included soil contamination by PbCl2 (0, 500, 1000 and 1500 mg/kg soil) and foliar spraying with silicon nano-fertilizer (0, 1.5 and 3 mM). Morphological studied traits including plant height, leaf number and area, fresh and dry weight of root and plant, root and stem diameter, physiological parameters such as photosynthetic pigments, electrolyte leakage, relative water contents, proline, carbohydrates, phenol, antioxidants were measured. Results indicated that lead stress reduced the morphological characteristics such as plant height, plant fresh and dry weight, and stem and root diameter, so that the increased content of lead led to decrease of plant dry weight, root weight, root and stem diameter, root length, plant height, leaf area and dry weight up to 57, 50, 20, 41, 15, 42 and 25%, respectively. Foliar spraying with silicon (3mM) led to improve most of morphological traits of coriander. The content of chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and carbohydrate in leaves was increased with increasing lead concentration in soil. However, silicon foliar spraying improved these traits under lead stress. Proline, phenol, flavonoid and antioxidant capacity were significantly increased with increasing concentration of lead up to 1500mg/kg. In general, it can be concluded that the use of silicon nanoparticles for coriander can reduce the negative effects of lead stress to a satisfactory level.
