Resistance of Raspberry Cultivars to Temperature Stress Factors during the Winter Period

Resumo

The paper presents the results of studies on the winter hardiness of raspberry cultivars and selected forms in field and laboratory conditions, which were conducted at the All-Russia Horticultural Institute for Breeding, Agrotechnology, and Nursery and its Kokino base station (Bryansk oblast). The objects of studies were 20 cultivars and ten selected forms of raspberry of various genetic and geographical origin. The main goal of the work was to study the resistance of raspberry cultivars and selected forms to temperature stressors of the winter period and to reveal the most winter-hardy genotypes. High winter hardiness was revealed for the Peresvet, Balzam, Beglyanka, and Rubin Bryansky cultivars and nine selected forms. The modeling of damaging winter factors revealed that the Gusar, Lazarevskaya, Volnitsa, and Meteor cultivars and selected forms 32-16-1, 1-15-1, 1-2-2, and 6-12-2 tolerated well a frost of –35°C in the middle of winter. Reliable resistance to a III winter hardiness component is featured by the Gusar, Meteor, and Volnitsa cultivars and selected forms 32-16-1, 1-4-2, 1-15-1, 1-2-2, and 2-12-1. Among the studied raspberry assortment, the genotypes with a high level of bud resistance to IV winter hardiness component were not revealed.