Document Type : scientific research article
Authors
1
Ph.D. Student, Department of Horticultural Science, Faculty of Agricultureal Sciences, University campus 2 University of Guilan
2
Department of Horticultural Science and Engineering, Faculty of Agricultural Sciences, University of Guilan
3
Associate professor, Department of Soil Science, Faculty of Agricultural Sciences, University of Guilan
4
Associate professor, Department of Seed and Plant Improvement Research, Agriculture and Natural Resources Center, , Agriculture Research, Education and Extension Organization
10.22069/jopp.2025.22858.3196
Abstract
Background and Objective: The plant Catharanthus roseus (L.) G. DON, belonging to the family Apocynaceae, is renowned for its abundant terpenoid indole alkaloids (TIA), with over 400 distinct alkaloids. Among the most significant active compounds are vincristine, vinblastine, and ajmalicine. The limited availability of vinblastine and vincristine, coupled with the increasing demand from communities and patients suffering from cancer, underscores the importance of cultivating the plant. As the effects of organic fertilizers on the cultivation of Catharanthus roseus have not been thoroughly studied, this research aims to investigate the influence of potassium humate on the growth and biochemical characteristics of the plant.
Materials and Methods: A field experiment was conducted at the Medicinal Plants Research and Education Center in Hamadan County over two agricultural season, 2022 and 2023, with three replications. The potassium humate treatments were applied at five levels: 0, 2.5, 3, 3.5, and 4 g m-2 through fertigation. The aerial and root organs were collected at flowering time (late August and mid-September), and growth traits, including fresh and dry weights of leaves, stems and roots were measured. Biochemical traits, such as the activity of oxidase and catalase in leaves, stems, and roots, as well as the total alkaloids in the leaves were also assessed. Data were analysed in factorial arrangement in a completely randomized block design using SAS software.
Results: The effect of potassium humate on the fresh and dry weights of leaves, stems, and roots, as well as the activity of peroxidase and catalase in leaves, stems, and roots, and the total alkaloids in the leaves of the plant were significant (p < 0.05). Additionally, the effect of the year on all these factors, except for the fresh weight of the roots and the activity of peroxidase in the roots, was significant (p < 0.05). The interaction effect of treatment × year was significant for the fresh and dry weights of leaves and roots, the fresh weight of stems, and the activity of peroxidase in stems (p < 0.05). The results indicated that the potassium humate treatment of 4 g m-2 resulted in the highest fresh and dry weight of the plant, as well as the highest activities of peroxidase and catalase, while the control treatment displayed the lowest amount. Based on the results from the means comparison of treatment × year, the highest fresh leaf weight (203.79 g m-2), dry leaf weight (33.47 g m-2), fresh stem weight (88.38 g m-2), and dry root weight (5.23 g m-2) were associated with the 4 g m-2 potassium humate treatment in the second year. Furthermore, the highest peroxidase enzyme activity (0.92 ΔOD min-1 mg-1 protein) in the second year and the highest fresh root weight (27.77 g m-2) were noted for the 3.5 g m-2 potassium humate treatment in the first year.
Conclusion: Application of potassium humate at a level of 4 g m-2 had the most significant impact on improving the growth indices, including the fresh and dry weights of the leaves, stems, and roots of Catharanthus roseus. Furthermore, the application of this fertilizer at 4 g m-2 had the greatest effect on the activities of the catalase and peroxidase enzymes. However, using this fertilizer at a level of 3.5 g m-2 had the greatest impact on the total alkaloid content in the leaves.
Keywords
Main Subjects
)