نوع مقاله : مقاله پژوهشی
نویسندگان
1 استاد، گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه مراغه، مراغه، ایران
2 دانشیار، گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه مراغه، مراغه، ایران
3 استاد، گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه زنجان، زنجان، ایران
4 دانش‌آموخته دکتری، گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه مراغه، مراغه، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction
Water scarcity is the most significant environmental stress or that limits plant growth in the world. Meanwhile, zinc is recognized as a vital micronutrient that plays a crucial role in the normal growth of plants. Its application has been shown to enhance both the quantity and quality of agricultural produce by promoting the photosynthesis rate, activity of antioxidant enzymes, and some osmolyte compounds such as proline. This enhancement can mitigate the adverse effects of environmental stresses, including drought. Therefore, in the present study, the effects of various amounts and methods of zinc application were investigated on the activity of antioxidant enzymes as well as the growth and grain yield of maize under drought stress conditions. The aim of this experiment was to improve the physiological aspects, growth and yield of maize under these conditions.
Materials and methods
The research was carried out in research station farm of the Faculty of Agriculture of the University of Zanjan as split-plot experiment conducted based on a randomized complete block design with three replications. The main factor included water stress (90%, 60%, and 30% of field capacity) and sub factors included fertilizer treatments include no fertilizer application, soil application of zinc at the10 and 25 Kg ha-1, foliar application of 5 g l-1 zinc at stem elongation, tassel emergence and milking stages. This research examined the characteristics of iron, zinc, and phosphorus in seeds, along with the enzymatic activities of catalase, ascorbate peroxidase, guaiacol peroxidase, and superoxide dismutase. Additionally, it assessed proline levels, leaf chlorophyll index, leaf area index, hydrogen peroxide concentration, malondialdehyde content, seed yield, and biological traits. The means were compared using the Least Significant Difference (LSD) test at a significance level of 5%, and data analysis was conducted using SAS software (version 9.3).
Research findings
Results of this experiment indicated that the interaction effect of zinc application and drought stress was significant for all traits, except for the biological yield and grain yield. The biological and grain yield were influenced by main effects. According to the Mean comparison, the occurrence of drought stress led to a decrease in grain Fe, Zn and, P concentration, and the antioxidant enzymes activity, including superoxide dismutase, guaiacol peroxidase, catalase, and ascorbate peroxidase. Additionally, drought stress negatively impacted the leaf chlorophyll index and leaf area index. On other hand, with increasing stress intensity, the amount of hydrogen peroxide (197%), malondialdehyde (256%) and proline (129 %) increased. In contrast, the application of zinc with enhancing these traits, led to decrease in the production of hydrogen peroxide and malondialdehyde. Furthermore, the results indicated that drought stress reduced grain and biological yield, and applying 25 Kg of zinc led to improvements in the grain yield (62 %) and biological yield (44 %).
Conclusion
The findings of this study indicate that the assessment of biochemical and morphological characteristics revealed that drought stress, particularly at elevated intensities, adversely affected nutrient absorption from the soil. This resulted in a reduction in grain element concentrations, leaf area index, and leaf chlorophyll index, as well as a decline in the activity of antioxidant enzymes. Conversely, drought stress was associated with an increase in proline levels. The application of zinc, particularly at a rate of 25 kg/ha, was found to enhance physiological, morphological, and yield-related parameters by intensifying the aforementioned traits. Specifically, under moderate stress conditions, zinc application led to a decrease in hydrogen peroxide and malondialdehyde levels, while simultaneously increasing proline and the activity of antioxidant enzymes. Furthermore, it is noteworthy that foliar application of zinc proved to be more effective in elevating grain element concentrations compared to soil application.
کلیدواژه‌ها [English]
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