Biological features of primrose Plagiorhegma dubium Maxim. and Jeffersonia diphylla (L.) Pers. in culture in the South Urals (Republic of Bashkortostan)

The purpose of research is to study the features of the phenological rhythm of growth and development, biomorphology, reproductive performance and agricultural technology for growing early-flowering ornamental species Plagiorhegma dubium and Jeffersonia diphylla in culture. An introduction study of these species was carried out under stationary conditions in the South Ural Botanical Garden-Institute of the Ural Federal Research Center of the Russian Academy of Sciences in 2019-2021 on the material of the collection exposition of shade-tolerant plants. When studying the phenology, biomorphological and reproductive indicators of species, methodological recommendations developed for botanical gardens were used. P. dubium and J. diphylla are long-vegetating, spring-summer-autumn-green perennials with a dormant period in winter. The beginning of the growing season comes after the snow melts - in early April. The studied species are characterized by short flowering and belong to the group of medium long-flowering plants. The duration of flowering for J. diphylla is on average 7 days, for P. dubium - 11 days. From the beginning of flowering to the full maturation of seeds, an average of 55 days pass. The vegetation period of the studied species lasts on average 180 days and in the conditions of Ufa ends in late September - early October. The tallest plant with a powerful habitus is J. diphylla. Its indicators in the vegetative and generative spheres, in contrast to P. dubium, are more significant. On the problem of introduction study of P. dubium and J. diphylla species, there is a small number of research works devoted to their biological characteristics and cultivation agrotechnics. These shade-tolerant species are highly decorative throughout the growing season. So far, studies on them in culture in the Southern Urals have not been carried out.