ASSESSMENT OF SOFT WINTER WHEAT VARIETIES ADAPTABILITY TO THE ECOLOGICAL CONDITIONS OF THE CENTRAL CAUCASUS FOOTHILL ZONE

The objective of the research was to study the environmental response of soft winter wheat accessions to the natural conditions of the foothill zone of the Central Caucasus In 2022–2024, 15 varieties of winter soft wheat were studied in the foothill zone of the Central Caucasus, including samples from the collection of the All-Russian Institute of Plant Genetic Resources named after N.I. Vavilov (VIR). Field trials were conducted in accordance with the State Variety Testing methodology. Various indices were used to assess drought resistance: spike linear density index (SD) — the number of grains in an ear/ear length; Canadian index (Ki) — grain weight per ear/ear length; plant productivity index (PPI) — the ratio of the product of the number of grains in an ear by the weight of the grain in an ear to the length of the ear; yield stability index (YSI). Drought resistance indices were calculated for all varieties based on yield data in the driest (2024) and more favorable (2022) years. The total score of each sample ranks for all indices was also calculated. Under drought conditions, soft winter wheat forms were selected that consistently provide all the main elements of the crop structure. The most productive and resistant to abiotic environmental factors varieties of winter soft wheat include 2 samples from Iraq № T1 and № T3 (V. graecum and V. ferrugineum), the varieties Arap and Naz (V. erytrhospermum) from Kazakhstan, Chornobrova (V. uralicum) from Ukraine and Livius (V. erytrhospermum) from Austria. Resistant to fusarium head blight include: Naz (V. barbarossa), Su-Mai 3 (V. ferrugineum), Livius and Arap (V. erythrospermum), № T1, T3, T17 from Iraq (V. ferrugineum and V. graecum), K-21923 (V. delfii). These samples, selected by a set of characteristics, are promising for use in breeding for drought resistance in the conditions of the foothill zone of the Central Caucasus. The proposed index system allows us to evaluate various aspects of drought resistance and adaptability of variety samples.