Influence of Ultraviolet Radiation on the Generative Sphere and Development of an Endemic Species Gypsophila Thyraica A. Krasnova (Caryophyllaceae)

Abstract

The peculiarities of the influence of ultraviolet radiation (UV-R) on the reproductive properties of the endemic, relict, rare species Gypsophila thyraica A. Krasnova s. str. with the aim of identifying the features of its adaptation to environmental conditions and predicting further reproduction. An analysis of seed germination, seed germination energy, features of seedling development, fertility and viability of pollen at different exposure options of UV irradiation was carried out. The stimulating effect of short-term UV-R irradiation (10-20 min.) on germination, energy of seed germination and seedling development was established. The energy of seed germination during exposure for 20 min. 2-3 times higher in irradiated samples than in non-irradiated controls; the analysis of morphometric indicators showed a doubling of the length of primary roots and the total size of seedlings in comparison with the control samples, in which deformed individuals prevailed, with slowed growth, fungal diseases were more often observed. It was established that under natural conditions, the fertility and viability of G. thyraica pollen varies between 75-85%. After additional UV-R irradiation at low doses, a gradual decrease in the fertilizing ability of pollen was observed; the percentage of deformed pollen increased with increasing exposure to radiation, which is a consequence of the destructive effect, first of all, on the shape. The viability of pollen under the influence of small doses of UV-R irradiation gradually increased (up to 91.0%), although the number of deformed increased. With long-term exposure to UV-R light (60 min.), pollen fertility increased, and viability decreased.