Drought tolerance of hybrid tea rose varieties in the conditions of the Right-Bank Forest-Steppe of Ukraine

Abstract

Purpose. To reveal drought resistance of hybrid tea rose varieties of garden group in field and laboratory conditions. Methods. Field, biometric, laboratory, statistical. The drought resistance of plants in the field was assessed according to S. S. Pyatnitsky 6-point scale (1961); experiments in the laboratory were to determine the water hol­ding capacity of leaves, their water deficiency, the ability to restore turgor, hydration of tissues according to the unified method of the Institute of Horticulture NAAS (Kytaiev et al., 1998, 2009). Results. According to visual observations in periods with low moisture supply, leaf turgor did not decrease, so in the field, drought resistance of hybrid tea roses was estimated at 5 points on a 6-point scale. In the laboratory, water deficiency in the leaves was calculated (as a percentage of the total water content in the state of full saturation). According to the indicators of the water-holding capacity of leaf tissues, varieties with the level of moisture loss in the exposure after 12 hours from the lowest to the highest, were selected. Conclusions. All varieties of hybrid tea roses from the collection of M. M. Gryshko NBG of NAS of Ukraine, included in the experiment, in field conditions were rather drought-resistant. According to the indicators of drought resistance of leaves from 44 model varieties, 9 with low (up to 22.30%), 5 with medium (up to 24.37%), 30 with high and very high level of moisture loss were identified (27.23–46.47%). Analysis of the research results shows that the physiological processes associated with water loss are a variety-specific, genetically inherited trait. Varieties of hybrid tea roses of diffe­rent geographical origin, which showed the criterion of drought resistance from medium to highest, can be recommended for cultivation in the Right-Bank Forest-Steppe of Ukraine.