Protein nitrogen as an indicator of determining the degree of stress in oats during soil drought

Abstract. The purpose is to studying the response of oats to soil drought by the degree of change in the content of protein nitrogen in the leaves and identifying the most drought-resistant varieties for the breeding process. Methods. In the experiment, 40 varieties of oats were used, for which soil drought during tillering and flowering was artificially modeled. Determination of protein content in oat leaves was carried out on the twelfth day after the cessation of irrigation, using the Bradford reagent. Results. The reaction of oats to soil drought in the critical phases of ontogeny (tillering and flowering), expressed as a change in the protein content in the vegetative parts, was studied. On average for the collection, the protein content in tillering was 13.6 %, varying from 10.3 to 16.9 %. In flowering, this indicator decreased to 6.6–14.4 %. It was established that soil drought during the tillering period had a minimal impact on the varieties Assol’, Novosibirskiy 5, Ulov, KROSS, Fakel, Sig, Privet, Megion, Barguzin and Argument. The decrease in protein content in these varieties varied from 7.4 to 10.8 %. In the varieties Pesets, Uran, L’govskiy, Bulanyy, Tigrovyy, Ekspress, Dedal, Narymskiy 943, Pokrovskiy 9, Rovesnik and Borets, soil drought during tillering led to a decrease in the protein content in the leaves by 20.4–30.8 %. The varieties Sig, Ulov, KROSS, Chizh, Novosibirskiy 5, Megion and Fakel were the most resistant to drought during flowering. During the analysis of the data obtained, it was revealed that the varieties L’govskiy 82, Privet, Peredovik, Assol’, Ulov, Novosibirskskiy 5, and Sig reacted to a minimum degree to drought during tillering and flowering. Scientific novelty. The response to drought for 40 oat genotypes was established and the relationship between protein content and plant biomass was determined by the beginning of harvesting. The most promising genotypes for breeding drought-resistant oat varieties have been identified.