The effect of impatiens extracts on growth and development of selected plant species

The thesis focuses on the allelophatic effect of three different species of touch-me-not growing in Slovenia. We prepared watter extracts from the roots and leaves of himalayan balsam (I. glandulifera), small balsam (I. parviflora) and touch-me-not plant (I. noli-tangere) that were tested on corn seeds (Zea mays) and radish seeds (Raphanus sativus). The main interest was to determine the differences in inhibitory effect between all three species, the diferences between root and leaf extracts and if higher concentrates have higher inhibitory effect on tested species. We observed seed germination and measured root and shoot length. In the end of the experiment we harvested both tested plant species and separately weighed roots and shoots. We passed biochemical analysis to determine if the extracts of Impatiens caused an oxidative stress in tested species. To determine the oxidative stress we measured total protein concentration, enzyme activity of guaiacol peroxidase (G-POD) and concentration of malondialdehyde (MDA). All of the extracts had inhibitory effects on growth and development of tested plants species. A significant inhibitory effect was observed with I. glandulifera and I. parviflora extracts. The root extracts had higher inhibitory effect compared to leaf exctracts. Extracts increased G-POD enzyme activity in tested species which is a marker of oxidative stress. Higher concentration of extracts had higher inhibitory effect mostly on morphological features compared to oxidative stress parameters.