Babak Sepehri; Hami dreza tohidi Moghadam; Farshad Ghooshchi; Meysam Oveysi; Pourang Kasraie
Abstract
Objective: Periwinkle herb, with the scientific name (Catharanthus roseus (L.) G.DON), is one of the most important medicinal plants globally. Besides having aesthetic features and ornamental applications, the plants’ leaves and root are rich in very important alkaloids. It is used in the chemotherapy ...
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Objective: Periwinkle herb, with the scientific name (Catharanthus roseus (L.) G.DON), is one of the most important medicinal plants globally. Besides having aesthetic features and ornamental applications, the plants’ leaves and root are rich in very important alkaloids. It is used in the chemotherapy of various cancers and the treatment of hypotension.Methods: In order to investigate the effect of growth regulator and spraying by zinc and magnesium nanoparticles under the conditions of drought stresses on total alkaloids, anthocyanin, total chlorophyll, the weight of wet and dry branches contain alkaloids, and the number of lateral branches of the periwinkle herb, an experiment was arranged with a factorial layout based on a completely randomized design under greenhouse conditions during years 2020 and 2021 in Tehran, Iran. The first factor was the dryness factor using evaporation pans (at three levels of 40, 60 and 80 mm), the second factor comprised the growth regulators (Shahid, auxin, gibberellin, cytokinin each at a concentration of 50 ppm) and the third factor included the nanoparticles (control, Zn, and Magnesium, each at a concentration of 1 mg, and the combination of zinc and magnesium, each at a concentration of 0.5 mg) were applied.Results: The results showed that in study of the effects of drought stress and spraying of zinc and magnesium nanoparticles on all investigated traits (total alkaloid, anthocyanin, total chlorophyll, fresh and dry weight of alkaloid-containing branches, and the number of lateral branches), there was a statistically significant difference at the level of 1% (P≤0.01). Also, in the investigation of the effects of growth regulators on investigated traits other than total alkaloid, a statistically significant difference was established at the level of 1% (P≤0.01). In the investigation of the mutual effects of drought stress and growth regulators on the fresh weight of alkaloids-containing branches, a statistically significant difference was established at the level of 1% (P≤0.01). The highest dry weight of aerial parts was observed under optimal irrigation conditions and under the influence of the gibberellin hormone (34.96 gr). However, in other cases, no statistically significant effect was observed on the target traits.Conclusion: Drought stress revealed defense mechanisms such as anthocyanin pigments and secondary compounds, and total alkaloids also increased with increasing drought stress. The highest percentage of total alkaloids was obtained under severe drought stress (1.57%). The use of micronutrient fertilizers in nano form increased the accumulation of dry matter and secondary compounds, and the effect of magnesium was greater than the effect of zinc. In the application of hormones, the use of gibberellin hormone had a greater effect on the fresh and dry weight of shoots under optimal irrigation conditions and drought stress.