УСТОЙЧИВОСТЬ ГИБРИДОВ КОЛОННОВИДНОЙ ЯБЛОНИ К НИЗКИМ ТЕМПЕРАТУРАМ В ОСЕННЕ-ЗИМНИЙ ПЕРИОД

he paper shows the results for resistance study of apple hybrid forms with columnar growth habit of I.V. Michurin Federal Scientific Center (Michurin FSC) to the temperature decrease upto 33 °C (First component of resistance) at autumn/winter period. The seedlings were obtained as a result of crossings of apple varieties and forms of popular local origin and of domestic breeding (Antonovka obyknovennaya,  Bessemyanka  Michurinskaya, Sokolovskoye, Tambovskoye, Blagovest, Kovrovoye, Svezhest), promising donors and sources of high winter hardiness, as well as of scab immunity. As a check variety, we used the columnar apple variety Strela, included in the State Register of Breeding Achievements and admitted for economic use in the Central Black Earth Region. The research was carried out in the Michurin FSC in the laboratory of individual genetics and breeding of fruit crops on the base of breeding and genetical center in 2017–2019. The artificial freezing technique is used. The method enables us to arrange the necessary temperature regime in laboratory conditions. The frost resistance of apples at the beginning of winter is significantly determined by summing up of temperatures, providing a successful transit of the second phase hardening. This can be realized just at slightly negative temperatures. In the years with a warm autumn/winter season, the plants do not take a definite resistance for the variety and they have to meet the winter being unprepead to low temperatures. In course of development of the new columnar apple varieties, the long-term researches enabled us to solve some items of low temperature resistance in plants at the beginning winter. According to the first component of winter resistance the following hybrids were singled out: 8–7(51) and 60–5(430) with previous names Druzhina and Brigada respectively which were sent to the State variety testing. The form 12–7(11) is studied still and is used in breeding for resistance to low temperatures at autumn and winter period.