Evaluation of the aesthetic qualities and adaptability of introduced ornamental apple trees from the genetic collection of the Orenburg Branch of the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery

Abstract

The study of ornamental and adaptive qualities of Malus Mill. from the genetic collection of ornamental crops of the Orenburg branch of the Research Center of Horticulture was carried out to assess the gene pool of introduced wild apple tree species and forms and identify suitable for the urban landscaping and the breeding process. Such characteristics as habitus, abundance of flowering, color and number of flowers in the inflorescence, color of vegetative organs, flowers and fruits during the season were taken into account; resistance to major diseases and adverse abiotic factors was evaluated. Additionally, the color of buds and flowers was characterized on the basis of the RHS (Royal Horticultural Society Color Chart). As a result of a preliminary survey on the complex of ornamental qualities and the level of adaptability, 5 most promising species were identified, which received the best ratings on the ornamental scale. Malus sikkimensis (Wenz.) Koehne ex C. K. Schneid. (31 points) was characterized by an attractive habit, the presence of flowers with a diameter of up to 40 mm and subsequently fruits that acquire a yellow-red color. Malus sargentii Rehder (29 points) was notable for its compact rounded crown, a large number of flowers with a diameter of 30 mm, followed by the formation of fruits with a dark red color. Malus floribunda Siebold ex Van Houtte (28 points) was distinguished by a large number of fragrant flowers in an umbrella-shaped inflorescence (5 — 7 pcs) with an average diameter of 30 mm, as well as attractive red-yellow fruits. Malus sieboldii (Regel) Rehder, M. toringo Siebold (28 points) was interesting primarily by the presence of 5 -7 flowers of 20 — 30 mm in the inflorescence and decorative fruits, the color of which varies from yellow to red. Malus niedzwetzkyana Dieck (28 points) attracted attention to the rich purple color of all organs due to the presence of a large number of anthocyanins, it was also worth noting the presence of a pleasant aroma during flowering and large flowers with an average diameter of 40 mm. The selected ornamental types of apple trees are favorable for use in landscaping of various scales, they are recommended for breeding work as initial parent forms.