Mohammad Ahmadi, Tohid Ali-Abbasi, Salim Farzaneh,
Volume 12, Issue 1 (9-2025)
Abstract
Objective: The particular susceptibility of rapeseed during the sensitive stages of germination and seedling establishment doubly underscores the urgent need to develop efficient and cost-effective management strategies to counteract salinity stress. In this regard, seed pre-treatment technology has gained attention as a promising and novel strategy to enhance plant resilience against environmental stresses from the very first stages of growth.
Method: This research was designed and conducted to comprehensively evaluate and compare the effects of applying various natural growth stimulants—including amino acids (at three concentrations: 2, 4, and 6 g kg-1 of seed), humic acid (at three concentrations: 3, 6, and 9 g kg-1 of seed), and seaweed extract (at three concentrations: 3, 6, and 9 g kg-1 of seed) both individually and in combination with the hydropriming method on the improvement of germination indices, growth, and biochemical responses of rapeseed (cv. Hyola 50) under different levels of salinity stress (0, -2, -4, -6, and -8 bar).
Results: Salinity stress had a significant inhibitory effect (p < 0.01) on most measured traits. With increasing stress levels up to -8 bar, root dry weight decreased by 65.3%, emergence percentage decreased by 32%, and germination rate decreased by 63.3% compared to the control treatment (no stress). In contrast, the activity of catalase enzyme, an indicator of oxidative stress, increased by 114%, demonstrating the plant's defensive response to unfavorable conditions. In this study, the combined treatment of hydropriming with humic acid (6 g kg-1 of seed) was identified as the most effective method, with a 153% difference in leaf dry weight compared to the worst treatment. This treatment comprehensively demonstrated a protective role against salinity stress by increasing root dry weight by 13.8%, catalase enzyme activity by 10.5%, and germination rate by 14%, while maintaining the chlorophyll index.
Conclusions: It can be concluded that pre-treating rapeseed seeds with natural growth stimulants, particularly as combined hydropriming treatments with amino acids (4 g kg-1 seed) and humic acid (6 g kg-1 seed), is a low-cost, user-friendly breeding strategy and represents a practical and implementable approach for farmers.
Highlights
- A comprehensive investigation of the effects of three types of natural growth stimulants (amino acid, humic acid, and seaweed extract) individually and combined with hydropriming to achieve a synergistic effect.
- Providing strong quantitative evidence of the mechanism of action through simultaneous measurement of growth and biochemical indices and demonstrating the critical principle of dose-response.
- Emphasizing the practical and cost-effective nature of the method for farmers, aiming to convert saline lands into productive areas as a sustainable solution.
