BIOMORPHOLOGICAL FEATURES OF ROSA BRACTEATA WENDL. DURING INTRODUCTION INTO THE SOUTHERN COAST OF CRIMEA

Rosa bracteata J.C. Wendl. is a resistant rose species, promising for selection work. This paper presents the study of the developmental characteristics for the species Rosa bracteata introduced into the Southern Coast of Crimea. It has been found that in the conditions of the South Coast, Rosa bracteata bushes reach a height of 2.5–3.0 m. The bushes are densely leaved, evergreen, with up to 9 leaflets in a complex leaf, flowers are plain, 5-petalled, large (up to 9 cm in diameter), white or creamy white. One flower blooms for 38 hours. In the conditions of the South Coast, Rosa plants do not go through a full development cycle; after flowering, no seeds or fruits are formed, the flowers dry out and sometimes fall off. The terms of initial phenophases (swelling of buds, opening of buds and leaves) may vary due to unstable meteorological conditions in spring. Budding occurs in early June when the sum of positive air temperatures is above 1 510 о C, flowering occurs when the sum of air temperatures is above 1 700 о C – usually in mid-June. Flowering lasts 115 days, with single flowers extending until early October. The plants are not affected by diseases or pests, they tolerate drought, hot and sultry summers well, and are of interest for use in selection work. Studies of the characteristics of anthoecology have shown that it has a number of adaptations for entomophily. Also, towards the end of flowering, the anthers bend towards the stigmas of the flower, thickly sprinkling them with their own pollen, which acts as an additional method of pollination – autogamy. Since Rosa bracteata does not form seeds under the conditions of the South Coast, we considered it as a source of valuable paternal traits.