Document Type : Original Article
Authors
1
1- PhD graduate, Department of Plant Production and Genetics, Faculty of Agricultural Science and Technology, University of Mohaghegh Ardabili, Ardabil, Iran
2
Associate Professor, Department of Plant Production and Genetics, Faculty of Agricultural Science and Technology, University of Mohaghegh Ardabili, Ardabil, Iran
Abstract
1. Introduction: Plants are constantly faced with adverse environmental conditions such as heavy metal stress. Heavy metal stress is one of the most critical abiotic factors that has attracted much attention in the past 30 years. Quinoa (Chenopodium quinoa Wild.) is an annual plant from the Amaranthaceae family, which has been cultivated for thousands of years in South America. The stress caused by the accumulation of heavy metals is considered one of the environmental stresses, which has a wide spread in the world and the effects It hurts plants under stress, and because these metals are not destroyed and have a high tendency to accumulate in biological organs, either by consumption of animals and through entering the food chain, or by direct consumption by humans, their destructive effects and in this sense they have harmful environmental effects. Therefore, this study was conducted to investigate the effect of hydropriming, biopriming (Trichoderma fungus), and coating seeds with nano-chelate on germination indicators and antioxidant properties of quinoa leaf extract (Chenopodium quinoa Willd.) under cadmium stress.
2. Materials and Methods: To investigate the effect of hydropriming, biopriming (Trichoderma fungus) and seed coating with nanochelate on germination indices and antioxidant properties of quinoa leaf extract (Chenopodium quinoa willd.) under cadmium stress, a factorial experiment was conducted in the form of a completely randomized design in four replications in the Laboratory of Seed Science and Technology of Mohaghegh Ardabili University in 2024. The experimental treatments included pretreatment methods at four levels (control, hydropriming, biopriming, and seed coating) and cadmium stress (control, 50, 100, and 150 mg/liter). Statistical analysis of the data and comparison of the average of the resulting data, after ensuring their normality, with Statistical software (SAS) Ver 9.4 was used.
3. Results and Discussion: The results showed that the cadmium stress of 150 mg/l decreased the germination percentage by 9.46%, the germination rate by 49.68%, and the seedling dry weight by 22.5%, and the quinoa seedling length by 66.6%. Also, cadmium stress was 150 mg/liter, catalase enzyme activity was 13.36%, peroxidase enzyme activity was 19.4%, polyphenol oxidase enzyme was about 37.97%, total phenol content was about 37.97%, hydrogen peroxide content was significantly higher, and it was about 12.5 to increased, by 30% and malondialdehyde increased by about 491.491%. Percentage compared to the control treatment. On the other hand, water pretreatment increased the germination percentage by 17.75% and the germination rate by 97.14%. Also, biopriming with Trichoderm fungus increased polyphenol oxidase enzyme activity by 27.79%, proline content by 65.25%, and hydrogen peroxide by 36.84%. The highest seedling length was related to biopriming with Trichoderma fungus, which was able to increase the seedling length by about 45.45 to 67.06 percent at the same level of cadmium stress compared to untreated samples. Under stress conditions of 150 mg/L of cadmium chloride, the highest catalase enzyme activity was observed in biopriming with Trichoderma fungus, which had no significant difference with hydropriming and coating seeds with nano-chelate, but was about 15.62 percent higher than seeds without pretreatment. Biopriming with Trichoderma fungus increased the peroxidase enzyme activity of quinoa seedlings by 16.87 percent compared to the control treatment. In general, at 150 mg/L cadmium stress, hydropriming and biopriming increased total phenol content by 21.87% and 28.86%, respectively, compared to the control. The highest proline content was observed in the 150 mg/L cadmium chloride stress treatment and was about 25.17% higher than the control treatment, but there was no significant difference with 100 mg/L cadmium stress. Cadmium stress (150 mg/L concentration) significantly increased the activity of polyphenol oxidase enzyme by about 37.97% compared to zero cadmium stress.
4. Conclusion: According to the results of this study, it can be concluded that biopriming with Trichoderma fungus at different levels of cadmium stress by increasing the vigor of seeds and seedlings and increasing the activity of antioxidant enzymes reduces the negative effect of cadmium stress and improves the characteristics of germination and growth of seedlings. But in many cases, hydropriming is not significantly different from biopriming, and in some cases, it has worked better. Therefore, water pretreatment is a simple and cost-effective method, and at the same time, it is simple and does not require complex technical knowledge; it can be easily implemented by farmers. Therefore, this method is recommended to improve germination, seedling growth, and increase the quality and strength of quinoa seeds.
Keywords
