Origin of remontant and non-remontant cultivars of groundcover roses Rosa L.

Abstract

Purpose. Find out the common parental components used for creating rose cultivars with a procumbent shrub crown shape in combination with the signs of remontance, as well as develop a generalized pattern of the origin of groundcover rose cultivars from the collection of the M. M. Hryshko National Botanical Garden of the National Academy of Sciences of Ukraine (NBS).Methods. Analytical and graphic. Genealogies with schemes were drawn according to S. G. Saakov and D. A. Riexta method.Results. It was determined that all the studied cultivars of groundcover roses had species of the Synstylae DC. section as part of the pedigree: Rosa sempervirens L., R. wichurana Creˆp., and (or) R. setigera Michx. Also, the pedigree of all studied remontant cultivars (‘Magic Meidiland’, ‘Anadia’, ‘Candia Meillandeˆcor’, ‘Heideschnee’, ‘Nature Meillandeˆcor’, ‘Red Fairy’, ‘Swany’, ‘Scarlet Meillandeˆcor’, ‘Blanc Meillandeˆcor’) included rose cultivars of Floribunda groups and Muskusnaya rose hybrids, which are absent in non-remontant cultivars (‘Rote Max Graf’, ‘Nozomi’).Conclusions. Among the parental components in the pedigrees of the studied varieties of groundcover roses, which provided a procumbent crown shape specific to them, there were species of the genus Rosa L. of the Synstylae section: R. wichurana; R. sempervirens; R. setigera. All studied cultivars acquire the sign of remontance by crossing with cultivars of the Floribund group, whose origin is associated with the remontant species: R. chinensis Jacq. and R. odorata (Andrews) Sweet section of Chinenis DC. (Indicae Thory); due to R. rugosa Thunb., section of Cinnamomeae DC., with optional repeated flowering, and also due to cultivars of the Hybrid Musk rose group, which origin is associated with the remontant species R. moschata Herrm. Cultivars created from a combination of only non-remontant species R. wichurana, R. setigera, R. sempervirens with R. rugosa were non-remontant (‘Rote Max Graf’,‘Nozomi’). Visualization of relationships between parental components of different hierarchical le­vels and the studied variety is presented in the dendrograms. A generalized scheme of the origin of groundcover roses cultivars has been developed, which allowed to identify the relationship between remontant and non-remontant cultivars through common parental components that provided the key feature of the group – the procumbent shape of the crown of a shrub. The results of the study can be used as a basis for highlighting and granting official status to a group of groundcover roses in the unified International Classification of Roses, which is under development.