Improvement and breeding
E. Danaee; V. Abdossi
Abstract
Salinity is one of the most important abiotic environmental stresses which restricts the growth and production of plants. On the other hand, silicon (Si) is the second most abundant element in the soil and alleviates the biotic and abiotic stresses in the plants. For this purpose, a greenhouse experiment ...
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Salinity is one of the most important abiotic environmental stresses which restricts the growth and production of plants. On the other hand, silicon (Si) is the second most abundant element in the soil and alleviates the biotic and abiotic stresses in the plants. For this purpose, a greenhouse experiment was conducted as a factorial in a completely randomized statistical design with three replications to investigate the effects of silicon and nano-silicon (50 and 100 mg l-1) on some morphophysiological and phytochemical properties of peppermint (Mentha piperita L.) under salinity stress at the different levels of sodium chloride (0, 50, and 100 mg l-1) in 2019. The results showed that the salinity stress significantly reduced the fresh and dry weight of aerial parts and root, and chlorophyll, total phenol, and protein contents. The activity of superoxide dismutase and peroxidase enzymes and essential oil percentage differed at the different salinity levels. The amount of proline also increased significantly due to the sodium chloride treatment of 100 mg l-1. The plants treatment with the different levels of silicon and nano-silicon reduced the negative effects of salinity stress on the evaluated indices. The nano-silicon treatment of 100 mg l-1 showed the highest inhibition of salinity stress effects on the growth indices, antioxidant enzymes activity, and essential oil percentage. Therefore, according to the results of this research, the foliar application of silicon and nano-silicon could be recommended to reduce the negative effects of salinity stress on peppermint.
Improvement and breeding
Sh. Ahmadi; M.J. Nazarideljou; A. Hassani
Abstract
Many studies have been conducted on the role of essential elements in various aspects of medicinal plant production. However, the role of silicon (Si) as a quasi-essential or beneficial element in the growth and development, quantity and quality of essential oil of many medicinal plants is unknown. In ...
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Many studies have been conducted on the role of essential elements in various aspects of medicinal plant production. However, the role of silicon (Si) as a quasi-essential or beneficial element in the growth and development, quantity and quality of essential oil of many medicinal plants is unknown. In this regard, different concentrations of silicic acid including 0 (control), 25, 50, 75, 100, and 125 mg l-1 were added to the standard Hoagland and Arnone nutrient solution, and morphophysiological reactions and secondary metabolites production of lemon balm (Melissa officinalis L.) were evaluated in soilless cultivation (hydroponic system). The fresh and dry weight of leaves and roots increased with the addition of Si to the nutrient solution compared to the control. The percentage of biomass changes varied depending on the concentration of Si, so that the plant fresh weight at 125 mg l-1 of Si increased by 41% compared to the control (without Si). However, the percentage of essential oil (fresh materials) in plants fed with Si increased significantly compared to control. Accordingly, the percentage of essential oil in different Si concentrations including 0, 25, 50, 75, 100 and 125 mg l-1 were 0.16, 0.21, 0.31, 0.33, 0.34 and 0.34(%), respectively. The reaction of lemon balm essential oil compounds to Si also indicated the important role of this element in the quality of the essential oil produced. The highest amounts of geraniol (21.27%) and citral (58.71%) were obtained in concentrations of 50 and 125 mg l-1 of Si, respectively. Also, the most important main compounds in various concentrations of Si (mg l-1) included citral+geraniol (Conc.0), citral+neryl (Conc.25), citral+linalool (Conc.50), citral+caryophyllene oxide (Conc.75), citral+geranyl acetate (Conc.100) and citral+geranyl (Conc.125). Based on the results of the experiment, Si as a beneficial element has a significant effect on the growth and development parameters, yield, and quality of essential oil of lemon balm.
