نوع مقاله : مقاله کامل علمی- پژوهشی
نویسندگان
1 گروه مهندسی تولید و ژنتیک گیاهی، دانشکده کشاورزی، دانشگاه شهید چمران اهواز، اهواز، ایران
2 مؤسسه تحقیقات و آموزش توسعه نیشکر و صنایع جانبی خوزستان، اهواز، اهواز ،
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and objectives: Drought stress is the major abiotic constraint affecting sugarcane productivity and quality worldwide. Water deficit not only reduces yield but also negatively affects key physiological and biochemical traits, including plant water relations, photosynthesis, chlorophyll content, and oxidative balance. Silicon, is a beneficial element known to enhance plant tolerance to abiotic stresses, particularly drought, by improving water status, preserving photosynthetic pigments, modulating antioxidant defense mechanisms, and promoting the accumulation of compatible metabolites. Silicon nanoparticles (nano-silica), owing to their small particle size and high specific surface area, exhibit greater bioavailability and physiological effectiveness than conventional silicon sources. Therefore, this study aimed to compare the effects of nano-silica and conventional silicon on drought tolerance and related physiological and biochemical responses in sugarcane.
Materials and Methods: The experiment was conducted during the 2024–2025 growing season using a split-plot arrangement within a randomized complete block design with three replications on sugarcane variety CP69-1062. Irrigation intervals (7, 10, and 13 days) were assigned to main plots, while foliar application treatments included a control (no application), nano-silica at 150 and 300 mg L⁻¹, and silicon at 300 and 600 mg L⁻¹were allocated to sub-plots. These. Foliar applications were applied twice during the rapid growth stage (BBCH stage 3), beginning in early April, with a 15-day interval between applications.
Results: Increasing irrigation intervals significantly reduced carotenoid content, chlorophyll a and b content, chlorophyll index, relative water content, cane yield, and sugar yield. In contrast, the activities of catalase, peroxidase, and superoxide dismutase, as well as malondialdehyde (MDA) concentration, increased significantly under water deficit conditions. Foliar application of nano-silica, particularly at 300 mg L⁻¹, effectively mitigated the adverse effects of deficit irrigation. This treatment significantly enhanced cane and sugar yield compared with untreated plants and silicon treatments. Moreover, nano-silica at 300 mg L⁻¹ increased chlorophyll index, chlorophyll a and b contents, maintained stomatal conductance and relative water content, and resulted in the highest silica accumulation in plant tissues. This treatment also showed the highest antioxidant enzyme activities and the lowest MDA content, indicating reduced oxidative damage. The superior performance of nano-silica is attributed to its higher bioavailability compared with silicon sources.
Conclusion: These findings indicate that silicon nanoparticles are more effective than conventional silicon in enhancing sugarcane tolerance to irrigation deficit. This improvement is primarily associated with enhanced photosynthetic capacity and a strengthened antioxidant defense system. Consequently, nano-silica represents a promising strategy for improving drought stress management and optimizing sugarcane productivity under limited irrigation conditions.
کلیدواژهها [English]
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