پژوهشنامه اصلاح گیاهان زراعی (Sep 2024)
Effects of ZnSO4 and Fe2O3 Nanoparticles of Lentil (Lens culinaris) on the Antioxidant System, Agronomic, Physiologic, and Root Characteristics under Drought Stress
Abstract
Extended Abstract Background: Lentil (Lens culinaris Medik.) is one of the main food legume crops in Iran, where it is grown as a rainfed crop in spring in cold regions. One of the obstacles of spring cultivation in cold regions is drought stress exposure at the end of the growing season in the late cultivation date, which dramatically increases null pods and decreases seed yield. Until introducing autumn cultivation, specific, and cold-tolerant lentil varieties, the only solution for this problem is to find ways to deal with the damage of drought stress. Nanotechnology serves as a precursor of the new industrial revolution that has the potential to bring alteration in agricultural production. Nanoparticles (NPs) have been applied for enhancing seed germination, growth, physiology, productivity, and quality traits of various crops under normal or stressful conditions. Therefore, to reduce the negative effect of drought stress at dryland conditions in late cultivations, the effect of ZnSO4 and Fe2O3 NPs at 0.5% and 1% were studied on the agronomic, physiologic, root traits, and antioxidant system of lentils in the cold region. Methods: A field study was carried out at the Dryland Agricultural Research Center (DARI) in Maragheh during the 2019-2020 growing season. Experiments were conducted in rainfed conditions using a complete block design with three replications. Treatments were no spray, 0.5% nano ZnSO4, 1% nano ZnSO4, 0.5% ZnSO4, 1% ZnSO4, 0.5% nano Fe2O3, 1% nano Fe2O3, 0.5% Fe2O3, and 1% Fe2O3. Treatments were applied at two stages (10 days after the plant first establishment and 50% of flowering) in the early morning and not on windy days. The Bilesavar variety, which is suitable for spring cultivation in cold regions, was used in this experiment. Plant height, relative water content (RWC), cell membrane stability (CMS), canopy temperature, and the normalized difference in the vegetative index (NDVI) were recorded during the growing season. The seed yield and 100 seed weight (HSW) were calculated after harvesting. The activity of ascorbate peroxidase (ASP), catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD), peroxidase (POX), and the contents of proline, chlorophyll a, chlorophyll b, and carotenoids were calculated in gathered leaf samples during the growing season. Results: Differences between treatments were significant for RWC, CMS, canopy temperature, NDVI, and seed yield at 1%, and for HSW at 0.5%. The highest seed weight was observed in using nano Fe2O3 0.5%, and the lowest belonged to no spray treatment. The lowest RWC, CMS, and the highest canopy temperature were recorded in no spray treatment. Analysis of variance results showed that differences between treatments for all biochemical traits were significant at the 1% level. Chlorophylls a and b contents increased using NPs, and the highest level belonged to 1% nano ZnSO4 treatment and as expected the lowest calculated in no spray treatments. The highest carotenoids, and the activities CAT, ASP, GPX, and SOD were observed in 1% nano ZnSO4 treatment. The lowest activity of these enzymes as well as the highest H2O2, proline, and malondialdehyde (MDA) belonged to no spray treatment. According to the results, seed yield was significantly correlated with CAT (0.81), GPX (0.88), SOD (0.80), H2O2 (-0.82), MDA (-0.90), proline (-0.89), chlorophyll a (0.83), chlorophyll b (0.64), carotenoids (0.74), HSW, (0.50), NDVI (0.86), canopy temperature (-0.76), RWC (0.84), and CMS (0.95) at the 1% level. The highest root length was respectively measured in 1% nano ZnSO4, 0.5% nano ZnSO4, 0.5% nano Fe2O3, and 1% nano Fe2O3. NPs had no effect on average diameter while applying 1% Fe2O3 led to the highest effect on the root volume. Root surface showed the highest increase by using 1% nano Fe2O3, 0.5% nano ZnSO4, and 0.5% nano ZnSO4. The highest root length belonged to 1% nano ZnSO4 and 0.5% nano ZnSO4 while this trait was lowermost in no spray treatment. Conclusion: According to the results, 1% Fe2O3 exerted the highest effect on agronomic and physiological traits while 0.5% ZnSO4 was effective on the antioxidant system, and ZnSO4 NPs positively affected the root length and average diameter. While Fe2O3 NPs were effective in improving the root surface area and volume.
