PARADOXAL EFFECTS OF MORPHO-PHYSIOLOGICAL PARAMETERS OF DANDELION (TARAXACUM OFFICINALE WIGG.S.L.) URBAN POPULATIONS

The influence of atmospheric pollution, caused by road transport, on the physiological and biochemical,ecological and morphological parameters of common dandelion plants (TaraxacumofficinaleWiggs.l.) is considered in the article. Multiphase dependences were obtained with a change in the direction of response,under the conditions of increasing traffic, in the germination energy and the weight of seeds, ripened in inflorescences, cut off on the fourth day after flowering. In the gradient of atmospheric pollution by motor vehicles, a complex three-phase dependence of the mass of seeds in the calathide, and the energy of their germination, is observed. The extreme values of these parameters are 13-20% higher, than the control values,and they are manifested when the traffic intensity is 2100 vehicles per hour, that allows to referthe dependence data to paradoxical effects. The critical mass of viable seeds for their germination was 0.23 ± 0.007 mg, which was 10% higher, than the previously defined critical mass of Taraxacumofficinale seeds. According to the Cheddock scale, the extent of interrelation between the weight of seeds and their germination is high (R 2 = 0.80). Excessive activation of protective systems is one of the signs of paradoxical effects. With anthropogenic load of 2100 vehicles per hour, a sixfold increase in the activity of guaiacol peroxidases was recorded. At the same time, the level of lipid peroxidation in plant leaves from the considered cenopopulation did not differ from control. Keywords: bioindication, plant adaptation, anthropogenic load, energy of germination.