Changes in the main economically valuable traits of a sunflower variety SPK Plus during improving seed growing

The research was conducted in 2020-2022 in the V.S. Pustovoit All-Russian Research Institute of Oil Crops, Krasnodar. The purpose of the research was to establish regularities of the displaying of the main economically valuable traits in a confectionary variety SPK plus at the selection of promising families by results of their studying in a nursery of progeny estimation. As initial material, we used progenies of individual plants of seed growing elite of the variety SPK plus selected by seed weight per a head, oil content, and 1000 seed weight. During a vegetative period, phenological observatins and biometric measurements were done due to the method generally accepted (Pustovoit V.S., 1967). Oil content in seeds was determined on a NMR-analyzer AVM1006 due to the state standard R8.597-2010, 1000 seed weight - due to the state standard 12042-80. To state a variability range of a trait we accounted its average, minimal, and maximal meanings. Transforming of a population structure under impact of selection was established distributing the individual families into groups of a trait degree. Intensity of discard was revealed by a ratio of rejected families amount and total amount in the initial population. Increasing of families with enlarged 1000 seed weight was determined using an asymmetry coefficient. During the years of research, an average meaning of 1000 seed weight in a progenies of the selected plants was equal to 126.2 g, in a control - 119.5 g. a share of biotypes having 1000 seed weight more than 150 g of the promising families was 3.5%, and in a control - 1.6%. For three years of the research, the variety SPK plus was significantly improved by a trait of 1000 seed weight competing to the control - a progeny of breeder seeds. The estimation and selection of individual plants in a population caused accumulation of highly productive biotypes that led to the yield increase by 0.5 t/ha comparing to the control. A duration of a period seedlings - flowering, plant height, and oil content did not changed, keeping the level specific for this variety.