| Abstrakt: |
Many authors who researched the effect of Zn on seed germination, plant growth and development showed that zinc is reducing the rate of seed germination and inhibiting stem and root elongation in different plant species. The aim of this study is to investigate and compare the effect of different concentrations of zinc on seed germination, stem and root growth, as well as the increase in fresh and dry (dry) weight in peas which is a dicotyledonous plant. Material for this research was pea's seeds. The substance used in the experiments is zinc sulfate (ZnSO4) in the following concentrations: 10-5, 10-4, 10-3, 10-2, 2 x 10-2, 4 x 10-2, 5 x 10-2, 6 x 10-2, and 8 x 10-2 mol (M). These concentrations have been used in tests in the form of aqueous solutions prepared with distilled water. The action of the substance during the experiment was called permanent - Permanent Treatment (T.P.), and limited - Before Treatment (P. T.) for 24 h, 48 h and 72 h. In both types the treatment is the same. The seeds, before being placed in germination, are cleaned with ordinary water and then with distilled water two or three times. We placed the seeds in the soil at a temperature of 26 0C. The percentage of germinated seeds is determined after 96 hours from the moment they are placed for germination. Determination of the length of the plant organs was done 10 days after the placement of the seeds for germination. Their length is determined by measuring the buds and the main roots and is expressed as the average for a stalk, respectively root. Ten days after the seeds are planted for germination, the increase of fresh and dry weight of peas is determined, depending on the concentrations of ZnSO4. Based on the obtained results it can be noticed that zinc sulfate in lower concentrations (10-5, 10-4, and 10-3 M) not only does not inhibit seed germination, but in many cases stimulates seed germination, when compared to high concentrations (2 x 10-2, 4 x 10-2, 6 x 10-2, and 8 x 10-2 M). Zinc sulfate in small concentrations (5 x 10-2, to 2 x 10-2 M) did not inhibit further growth of previously germinated seeds. High concentrations with 48 h and 72 h pre-treatments (4 x 10-2 to 8 x 10-M) significantly inhibit further growth of shoots and roots. This phenomenon is more pronounced especially in peas because we do not have the development of these vegetative organs at all, while in maize we have a poor development. Small concentrations of zinc sulfate stimulate stem and root growth. The greatest inhibitory effect of high concentrations occurs on the growth of peas root rather than corn. This is because the cell wall as well as the cell membrane in peas is thinner and more permeable to zinc sulfate. [ABSTRACT FROM AUTHOR] |
