Improvement of Functional, Morphological, and Physiological Traits of Camelina (Camelina sativa) Using Iron Nanoparticle and Putrescine Sprying

Applying innovative nanotechnology in agriculture is considered as one of the promising approaches to obtain significant increases of crop yield. Nanoparticles (NPs) are considered potential agents for agriculture as fertilizers and growth enhancers and using of nano-fertilizers has led to an increasing in the efficiency of nutrients, the correct management of fertilizer consumption, and a reduction of the frequency of fertilizer application. Stimulants are compounds that initiate signals for cells to increase or decrease the production of secondary metabolites and plant defense response. Stimulants such as Putrescine play a role in regulating various plant physiological processes. In this regard, considering the importance of using new technologies, including nanotechnology, in sustainable agriculture to increase the quantitative and qualitative performance of agricultural products, especially oil-medicinal plants, and the lack of sufficient information about the use of iron nanoparticles and polyamine putricine in Camelina plant nutrition, The effect of foliar spraying of these stimulants on functional, morphological and physiological traits of Camelina plant (Soheil veriety) was evaluated.

This research was conducted as factorial layout based on a randomized complete block design with three replications at the research fields of Baye-Kala Agricultural Research Station (BARS) at Neka city in 2021. The studied factors included iron nanoparticles in four concentrations (0, 20, 40, and 60 ppm) and polyamine putrescine in four concentrations (0, 0.5, 1, and 1.5 mM). Each experimental plot was prepared in 6 square meters area and the studied treatments were applied by foliar spraying at the beginning of the reproductive phase of the plant. Two weeks after applying the treatments, sampling was done to evaluate the different traits of the plant. After checking the normality of the data, they were analyzed with SAS (ver 9.1) software; obtained averages compared with using Duncan Test at the 5% probability level.

The results of variance analysis indicated the significance of the simple effect of iron nanoparticles and putrescine on all the studied traits at the 5% level, as well as the significance of the interaction of the two factors on all the studied traits except carotenoid and peroxidase in the reproductive stage at the 5% level. According to the results, the highest amount of carotenoid (0.142 and 0.141 mg.g-1, respectively) and peroxidase (4.96 and 4.38 mg.g-1, respectively) were observed in application of 60 ppm iron nanoparticles and 1.5 mM putrescine which had no statistically significant difference with the concentration of 40 ppm iron nanoparticles and 1 mM putrescine. The results indicated that the highest amount of flavonoid (40.72 mg.g-1), soluble sugar (139.27 mg.g-1), and plant height (115.75 cm) were observed in the treatment combination of 60 ppm iron and 1 mM putrescine, the highest percentage of oil (41.76) and protein (27.77) were observed in the treatment combination of 40 ppm iron and 1.5 mM putrescine and the highest amount of grain yield (210.27 g) and morphological components of yield were observed in the treatment combination of 40 ppm iron and 1 mM putrescine. The correlation result showed that there were the most positive and significant correlation values among the physiological traits and the yield trait had a positive and significant correlation with plant dry weight (0.44) and oil percentage (0.40).

The results have demonstrated that foliar application of 40 ppm iron nanoparticles and 1.5 mM putrescine significantly enhanced various growth characteristics, including photosynthetic pigment content, crude protein, oil content, as well as the physiological and morphological aspects of Camelina. Additionally, the application of iron nanoparticles and putrescine via a uniform supply of low-consumption nutrients has been shown to strengthen the plant's defense system, ultimately leading to improvements in the growth, development, and yield of the medicinal-oil Camelina plant.