The influence of complex compounds of zinc, copper and platinum on germination, growth and amount of secondary metabolites of alfalfa (Medicago sativa L.)

Medicago sativa L. (alfalfa) is a herbaceous plant of great importance in agriculture. The chemical composition of the substrate affects the mineral supply as well as the growth, development and metabolism of the plants. Therefore, the aim of this experiment is to determine the influence of zinc, copper and platinum complexes ([ZnCl₂(en)], [CuCl₂(en)], cis-[PtCl₂(NH₃)₂], en = ethylenediamine) on the germination and growth of alfalfa and on the content of phenolic compounds. Alfalfa seeds were sown in three separate groups and treated with the above complexes, the fourth group being the control. The growth of the vegetative part was observed after the tenth, twentieth and thirtieth day. The percentage of germination was recorded for each experimental group. At the end of the treatment, the aerial parts of each group were dried and prepared for extraction with methanol, after which the quantitative composition of phenolic compounds was analyzed by liquid chromatography.The results obtained show that [CuCl₂(en)] has the best effect on the germination percentage, while the treatment with the platinum(II) complex - cis-[PtCl₂(NH₃)₂] showed a significant effect on the growth of alfalfa. The results of chromatographic analysis showed that [ZnCl₂(en)] and [CuCl₂(en)] improved the synthesis of phenolic compounds of alfalfa, with a significant content of catechins in the treatment with the copper complex compared to the control group. Based on the obtained results, it was concluded that the complex compounds have a significant effect on the germination, growth and phenolic compounds content of alfalfa, with different effects for each of the studied processes.