نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 گروه مهندسی علوم باغبانی و فضای سبز، دانشکده تولید گیاهی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران.
2 گروه مهندسی علوم باغبانی و فضای سبز، دانشکده تولید گیاهی، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Water and soil salinity is one of the most serious problems in agricultural production. Silicon is one of the elements that benefits the growth of many plants under various biotic and abiotic stresses and can activate certain plant defense mechanisms. Nitric oxide is also a compound that reacts rapidly with reactive oxygen species (ROS) under stress conditions and acts as a signaling molecule in response to various biotic and abiotic stresses. Therefore, the present study aimed to investigate the role of silicon and nitric oxide in mitigating the destructive effects of salinity on Zard olive cultivar.
Materials and methods: The experiment was conducted on one-year-old olive plants (cv. Zard) in a greenhouse. Salinity treatment was applied from the beginning of the experiment at four concentrations (0, 50, 100, and 150 mM sodium chloride) along with irrigation with tap water for 90 days. Saline water irrigation intervals were considered to be 4 days. Foliar application of the resistance-inducing agents including nano-silicon (at concentrations of 100 and 200 mg/L) and sodium nitroprusside (at concentrations of 0.5 and 1 mM) was carried out alongside a control in four stages at 20-day intervals. Morphological characteristics were measured after 90 days. Morphological characteristics were: length of the longest shoot, width of the largest leaf at the fourth node, internode length between the fourth and fifth nodes (from the top), percentage of green leaves, percentage of necrotic leaves, percentage of abscission leaves, thickness of the largest leaf at the fourth node, and percentage of morality. Fresh and dry weights of leaves, stems and roots, relative leaf water content and ion leakage were also other traits examined.
Results: The interaction effect of salinity and elicitor was significant for internode length, leaf width, percentage of green leaf, fresh and dry leaf weights, and LRWC content and decreased with increasing salinity levels. Foliar application of elicitors, especially nano-silicon, mitigated the damage caused by salt stress. As salinity increased, especially at 150 mM NaCl - elicitor control, leaf abscission increased, while foliar application of elicitors significantly reduced it. Ion leakage also increased with increasing salt concentration, indicating reduced membrane stability under salt stress conditions. Foliar application of inducers, especially nano-silicon at 200 mg/L, enhanced membrane stability and significantly reduced ion leakage. Salt addition and also foliar application of elicitors independently increased leaf thickness compared to the control. Salinity reduced shoot length, while foliar application of both elicitors effectively increased this parameter compared to the control. The highest morality and leaf necrosis percentages were observed in the 150 mM NaCl treatment, and foliar application of elicitors reduced leaf necrosis and morality compared to the control. Salinity independently and significantly decreased fresh and dry weights of roots and stems. Foliar application, especially nano-silicon at 200 mg/L, improved stem weight.
Conclusion: Zard is one of the sensitive cultivars of olive to salinity. This experiment demonstrated that high salt concentrations led to a decline in growth characteristics and relative leaf water content. Additionally, salinity caused an increase in ion leakage, indicating reduced membrane stability. Foliar application of nano-silicon and sodium nitroprusside compounds, particularly nano-silicon at 200 mg/L, improved growth traits under salt stress conditions.
کلیدواژه‌ها [English]
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