Some features of embryology of Rosa spinosissima L., R. canina L. and R. х damascena Mill. intact and virus-infected plants

Due to high decorative and economically valuable traits, roses have long been used in garden and park construction, and as medicinal and aromatic raw materials. Selection carried out with roses for many years, has resulted in more than 30 thousand cultivars. To create new forms and varieties, it is necessary to in-depth know species biology, including developments of generative elements. This paper shows the study of male and female generative structure formation in two wild species of Rosa genus, Rosa spinosissima L. and R. canina L., naturally grown on the north-eastern slope of Mount Chatyr-Dag, and in two R. ½ damascena Mill. cultivars, which may be involved in breeding as parental plants. As a result, we have determined the main embryological types of generative sphere formation in these species. It has been shown that the anthers are four-nested with two thecas, the wall of microsporangium is formed centripetal. A formed wall of microsporangium consists of epidermis, endothecium, 2-3 middle layers and tapetum, which is a derivative of a secondary parietal tissue...