Shevel' L. Biological peculiarities of the Callistephus chinensis (L.) Nees plants and their usage in the breeding process

The paper is dedicated to studying the morphobiological peculiarities of the China C. chinensis cultivars under the influence of biotic and abiotic factors as well as the plants reaction to the growing conditions. The results of the research will contribute to the development of the breeding process and creation of this crop cultivars which would distinguish themselves for the high decorativeness level, early flowering terms and stable crop of high quality seeds sown to the open ground under the conditions of the Ukraine's Lisosteppe. The climatic factors of the above mentioned zone have appeared to provide the passage of the investigated crop plants seasonal development full cycle. The sowing terms effect considerably the plants height, their habitus, cut floriferous shoots amount. The plants sown in early terms are notable for the higher coefficient than those sown in late ones. The blooming period fluctuates among the cultivars from 95 ('Bordyurna Rozheva') to 143 days ('Samanta'). The dependance of the fusarial wilt catching by the China aster plants on the seeds formation places in flower clusters, their sowing terms, methods of growing, and interphaze period "bud formation - flowering" has been estimated on the basis of the phenological dates fixation. It is the plants grown from the seeds collected from the central, first and second flower clusters that are the most fusarial wilt resistant ones. Those from the third, fourth and other flower clusters are affected strongly. The weakest affection is detected on the plants attained as a result of the late autumn sowing. The researches have shown that the mutagens influence on the studied crop plants is different. They have effected rather temperately the growth and development acceleration, however it has not decreased the interphase periods. At the same time the mutagens influenced essentially the increase of the variability range concerning the bush height and diameter as well as the primary shoots amount. As a result cultivars of a new generation have been created that differ a lot from derivative forms regarding the level of decorativeness and seed productivity. The C. chinensis cvs and hybrids drought - resistance level as for the conductivity indices depends considerably on weather conditions. The cultivars with the greatest commercial point have been determined and recommended for production. That will enable to increase their growing economic efficiency in the Lisosteppe.