Study of Pine Strawberry Frost Resistance by Artificial Freezing Method

Abstract

The study of the frost resistance was carried out in 2017–2019 on the basis of the Laboratory of Physiology of Fruit Plant Resistance, Russian Research Institute for Fruit Crop Breeding. Strawberry cultivars of different ecological and geographical origin (‘Kokinskaya Rannia’, ‘Rosinka’, ‘Solovushka’, ‘Tzaritza’, ‘Urozhaynaya TzGL’ – Russia; ‘Sara’ – Sweden; ‘Alba’, ‘Marmolada’ – Italy; ‘Korona’, ‘Sonata’ – Holland) were used as experimental material. The frosts resistance of strawberry varieties was studied in the laboratory conditions was used by artificial freezing. A model of strawberry plant selection was developed to determine the main components of winter hardiness. On the basis of preparation of plant samples for modeling of damaging factors of the winter period, storage conditions of experimental plants were developed. Plant hardening and modeling of damaging factors of the winter period were carried out with the additional modification for strawberries. As a result of the artificial freezing, the damage to the tissues of rhizome and apical buds of shoots of strawberry varieties of different ecological and geographical origin were evaluated in early winter period and during thaws in winter. It was determined that the decrease in the temperature to -15°C at the end of November did not cause irreversible damage to the strawberry varieties. The decrease in the temperature to -20°C in early December increased the damage to the studied strawberry varieties. During the winter it was determined that the strawberry response to the thaw increased by the end of the winter period. The decrease in frost resistance is primarily due to the resumption of growth processes under the influence of positive temperatures. As a result of determining the components of winter hardiness, the varieties Solovushaka, Tzaritza (Russia), Sara (Sweden) and Korona (Holland) showed the greatest potential of frost resistance.