Kovalenko V. Biological features of Scilla sibirica Haw. and Tulipa quercetorum Klok. et Zoz (Liliaceae Juss.) under southeastern condition of Ukraine

The dissertation paper is devoted to studying of biological, morphological, anatomical and ecological features of Liliaceae Juss. family representatives, namely S. sibirica and T. quercetorum. The spreading of S. sibirica and T. quercetorum in the south east of Ukraine is studied. The range of air temperatures for each phenological phase of S. sibirica and T. quercetorum development under conditions of the south-eastern part of Ukraine is determined. The seed productivity and the germination of investigated species are studied. The age structure and the densitiy of S. sibirica and T. quercetorum population is also studied. The way for determining the age of the plant S. sibirica during the pregenerative period of growth depending upon the number of bulbous scales is suggested. Biomorphological changes S. sibirica of plants, depending on the age of plants, are investigated. It is stated that in the forest phytocenosis bigger plants of T. quercetorum are formed than in the meadow one. The influence of illumination intensity on seed formation of T. quercetorum is studied. The ways of S. sibirica and T. quercetorum bulbs immersion into the soil are studied. It is stated that after seeds germination the plants of both species deepening stolonis are formed, which immerse the bud into the soil, from which the bulb is formed. Further bulb deepening of S. sibirica occurs at the expense of contractile roots contractive activity; as to T. quercetorum - at the expense of positive geotropic stolon growth. It is proved that the contraction of contractile roots occurs at the expense of root bark cell form transformation from longitudinal to spherical as a result of cell growing direction reorientation.