Ito-hybrids - a promising group of peonies for landscape design in Western Siberia

The research objective was the assessment of the prospects of using Ito-hybrids of peonies in the conditions of the forest-steppe of Western Siberia. Actually treelike peonies were insufficiently winter-hardy in the conditions of continental climate of the forest-steppe of Western Siberia. More perspective was Ito hybrid group created due to hybridization of treelike yellow and floral types and terry grassy varieties. Studying of the rhythms of growth and development, ontogenesis and elements of organogenesis was carried out to CSBG SB RAS (Novosibirsk) in 2013-2020 at the assessment of adaptive potential of Ito hybrids. Model types were involved in comparative researches. It was revealed that the varieties of the peonies from the Ito-hybrids group were long-growing, characterized by spring-summer-autumn green phenorhythmotype. Flowering is annual, occurs 8-12 days later than in the varieties of herbaceous peonies, while it is longer, up to three weeks. In vegetative propagated plants, ontogenesis was studied starting from the virginal state (v), in which they were during 1-2 growing seasons. Young generative plants (g1) in the first year formed 1 generative shoot with a single flower and 2-3 vegetative shoots, the next year two shoots bloomed, the number of vegetative shoots increased slightly (2-4). Then, after 4 years, the plants passed into mature generative state (g2), in which the peonies could stay for many years (10 or more), without reducing their decorative effect. A characteristic feature of Ito-hybrids, probably inherited from tree peonies, is the laying of a large apical bud on vegetative shoots in late summer, in which all leaf scales have the rudimentary leaf blade and almost do not differ from leaf primordia. Solitary and group planting of Ito-hybrids and peony species can be used for such landscape design techniques as rhythm, contrast and nuance due to powerful, durable bushes, the original shape of the leaf blade and a rich color palette.