Protein content in grain of collection samples of common pea and its adaptive properties

The purpose of the research was to identify samples of the collection of peas with a high and stable protein content in the grain, as a starting material in breeding for grain quality. Of the 130 studied samples of the collection of peas, which had at least 25.0% of the protein content in the grain, on average over the years of research, only 13 samples had a protein content of at least 25.0%. The highest minimum protein content was observed in the Russian-bred OMK-3 sample, which had an indicator of 26.1%. For the rest, the minimum value was from 25.0 to 25.3%. The maximum protein content over the years of research in pea samples was from 25.8 to 29.7%, of which samples 193/73 (Ukraine) (29.7%), OMK-3 (Russia) (29.5%), NS-01-68 (Bulgaria) (29.1%), B-887 (Russia) (28.7%) and Orel-330 (Russia) (28.7%). The average value of the coefficient of variation for varieties, characterizing intravarietal variability, was 6.8% on average for the collection, with the lowest value being 1.2% and the highest value being 15.9%. In the 13 isolated samples, the intravarietal variability was lower than the average for the collection as a whole (1.2-6.6%), except for sample 193/73 (Russia), for which it was 7.3%. This sample has the highest average and maximum protein content in the years of research. The selected 13 samples from the pea collection are of breeding value as initial parental forms in the direction of increasing the protein content in the pea grain and enhancing the stability of this indicator.