The features of protein formation in pea grain under the conditions of West Siberia

The experiments were carried out at Omsk Agricultural Scientific Center (Omsk ASC) in 2010-2019 to study the features of protein formation in the mid-season field pea varieties (Pisum sativum) of the semi-leafless morphotype under the conditions of the southern forest-steppe of West Siberia. The following varieties developed at the Omsk ASC were investigated: Omsky 9, Demos, Blagovest, and Triumf Sibiri. The varieties were sown in the competitive variety trial nursery on autumn moldboard plowed field; the forecrop was spring soft wheat. The protein content in grain and thousand-kernel weight was determined. The weather conditions were contrast with the hydrothermal index for the period from May to August from 0.58 in 2010 to 1.44 in 2018. On 10-year average, the varieties differed slightly regarding the protein content in grain (22.41-23.36 %) and the yields (2.97-3.17 t hectare). However, the protein accumulation in grain had variety-related peculiarities. On average, the protein content did not depend on the yield and was determined by the external environmental factors, particularly on the weather conditions during the period from sowing to the beginning of flowering (from the 2nd and 3rd ten-days of May to June). The maximum percentage of protein (23.54-26.38 %) was observed in 2015-2017 under optimal or moderately dry hydrothermal conditions of the growing season. A positive correlation of the thousand-kernel weight and the yield (r = 0.39-0.78) and the protein yield per hectare (r = 0.22-0.71) was revealed. To a greater extent, the protein yield was determined by the yield level (r = 0.71-0.99) rather than by the protein content in the seeds (r = 0.01-0.66). It was found that only the Blagovest variety showed high dependence of the protein content in grain on its yield per hectare. Accordingly, a fairly high protein yield per unit area may be obtained when growing both high-protein and high-yielding pea varieties.