Anatomy of the leaf blades of Waldsteinia ternata (Stephan) Fritsch (Rosaceae) grown under different light conditions

The paper reports the results of a comparative study of the anatomical structures of the leaf blades of Waldsteinia ternata grown under different light conditions in the Siberian Botanical Garden of Tomsk State University. Waldsteinia ternata is a tertiary nemoral relict from the mountains of southern Siberia, which is found in a limited number of taiga communities due to narrow environmental tolerance to various factors. The species remains poorly studied; comprehensive studies of the anatomical features of its leaves have not been performed on the territory of Russia. Leaves of W. ternata are dorsoventral and amphistomatous with anomocytic type stomata. The plants are classified as mesophytes. The relationship between the development of the anatomical structure of leaves and light conditions was revealed. The W. ternata plants grown in the sun showed an increased number of stomata and epidermal cells, an increased thickness of the leaf and mesophyll, and an increased number of cells of the upper and lower epidermis, that is, the plants exhibited heliophytic features of plant adaptation to good light conditions. At the same time, the vascular tissues of the plants grown in the sun were less developed, which reflected their adaptation to unfavorable water conditions. A number of relative indicators, such as the stomatal index of the lower epidermis, the ratio of the palisade to spongy mesophyll, and the ratio of xylem to phloem, did not change under different growth conditions. Thus, under different light and water conditions, W. ternata acquires helioxeromorphic or sciomesomorphic features

Pre-sowing stimulation of wheat with UVB radiation of XeCl-excilamp

The share of UVB spectrum range (290-320 nm) in the solar radiation flux accounts for an average of about 1.5% ofthe radiant flux on the planet. Taking into account the fact that plants adapt to living conditions in the course of evolution, it can be assumed that the flow of UVB radiation is also used by plants, but at the level of subdoses that reach the Earth's surface. The aim of current work is to study the growth and development of spring wheat ("Irgina" cultivar) when treated with subdoses of UVB radiation. For processing, XeCl-excilamp (High Current Electronic Institute SB RAS) radiation was used. The spectrum of this lamp is a narrow band with a maximum at a wavelength of 308 nm, which corresponds well to the UVB range. In the course of study, the pre-sowing UVB radiation dose values for seeds were found, under the influence of which wheat sprouts had an increase in such indicators as the length and dry weight of the root, the length of the leaf and the ratio of the root/shoot masses. It was shown, that as plants developed, the nitrogen balance index was always higher in the experiment with radiation in plants whose seeds were subjected to pre-sowing treatment with UVB radiation. This indicates the activation of growth and development processes in plants, as well as the accelerated absorption and assimilation of nitrogen compounds. Under the action of dose 0.5 J/cm2 the weighting parameters grain productivity such as weight of grains per ear, spike weight, weight of 1000 pcs seeds and the grain yield exceeded the check by 10.2 %. The UVB processing did not affect the quality of the wheat grain. Based on the obtained data, it is concluded that the use of XeCl-excilamp UVB radiation for pre-sowing stimulation of wheat is promising

Effect of nanosecond repetitively pulsed X-ray radiation on the sowing quality of seeds and the productivity of wheat

The effect of presowing treatment of wheat seeds with nanosecond repetitively pulsed X-ray (RPX-ray) radiation at a dose of 0.07 Gy and pulse repetition frequencies of 13 and 25 Hz on the sowing quality of seeds and the productivity of plants has been studied