USE OF INTERSPECIFIC HYBRIDIZATION IN THE BREEDING OF ADAPTIVE HYBRIDS AND SORTS OF GARDEN CHRYSANTHEMUM (Chrysanthemum morifolium Ramat.)

Abstract

Many garden chrysanthemums bred across the world are not fully winter hardy. Many are damaged by fungal diseases due to a high humidity and are late flowering. This makes them unsuitable for general commercial marketing. Since 2000 we have been conducting a breeding program using natural species of the genus Chrysanthemum that are adapted to the local conditions. The strategy of breeding adaptive hybrids and varieties of chrysanthemum native to Russia was proposed based on their biological, genetic peculiarities and natural resources of Chrysanthemum with the use of interspecific hybridization. Research objects are the first generations of interspecific hyb rids of F1obtained previously by the author as a result of the hybridization of varieties and wild species of Chrysanthemum. Derived from different species and varieties, F1hybrids were crossed among themselves to obtain the multicomponent F2progeny. F2seedlings with winter hardiness, resistance to Puccinia horiana Henn. and early flowering were used in closely related crosses. The offspring of F3from closely related crosses were also assessed and selected according to adaptive and decorative characteristics. Inclusion in the selection process of various sources of winter hardiness and resistance to P. horiana allowed positive characteristics to be increased in F2and to be revealed in F3. Adaptive signs of the wild species Chrysanthemum naktongense Nakai, C. coreanum (H. Lév. et Vaniot) Nakai, C. zawadzkii var. tenuisectum Kitag., C. leiophyllum Nakai, and C. zawadzkii subsp. acutilobum (DC.) Kitag., which have formed and fixed during evolution, were inherited and manifested in offspring of the multicomponent hybrids and the closely related crosses. Promising interspecific forms with biological signs determining the possibility of growing in extreme conditions of the subregion were selected.