Abstract
The objective of the research was to evaluate 22 genotypes of hulled oats from the VIR collection for adaptive indicators of the "grain protein content" trait and to identify the most promising ones for subsequent inclusion in breeding programs. The work was carried out in the period 2023–2025 in the Kirov region. The "cultivar" factor had the greatest influence on the protein content in grain – 69.01 %. The coefficient of variability (CV) of the trait by the years of the research changed from a low of 1.02 % (k-15622 ‘Chemal’, Russia) to an average of 17.22 % (k-15607 UFRGS 930597-4, Brazil). The best conditions for the formation of increased protein content were formed in 2023 (environment index 0.56). On average for 2023–2025, the maximum protein content in grain was obtained from accessions from Sweden k-15057 and k-15054 (11.88 and 11.91 %, 2.72–2.75 % higher than the ‘Arkhan’ standard). Based on the studied trait, stress-resistant accessions were identified: k-15622 (Russia), k-15402 (France), and k-15057 (Sweden). Accessions k-15606, k-15607, k-15609 (Brazil), and k-15054 (Sweden) were characterized by high values of genetic flexibility (11.06–11.90 %). Stress resistance and genetic flexibility were combined in k-15057 Plym (Sweden). High values of the intensity level (И = 25.5–32.0) for the “protein content in grain” trait and the response coefficient (Kr = 1.30–1.40) were noted in the samples k-15040 local (Kenya), k-15600 UFRGS 086208-3, k-15607 UFRGS 930597-4 (Brazil), k-15700 Olands (Sweden). The genotypes k-15622 (ИС = 9.88), k-15402 (ИС = 6.60), k-15054 (ИС = 1.70), k-15057 (ИС = 2.72) were distinguished by stability in protein content. In 11 genotypes the adaptability coefficient (CA) was greater than 100 %. Ranking by the adaptability indicators made it possible to identify accessions capable of producing the highest protein content in grain under the conditions of the cultivation region: k-15600 UFRGS 086208-3, k-15607 UFRGS 930597-4, k-15609 UFRGS 953195 (Brazil), k-15700 Olands, k-15054 Sirius II (Sweden) (sum of ranks 54–61). These genotypes are distinguished by their adaptability to changing environmental conditions according to the “grain protein content” trait and are recommended for use in creating new breeding material.