Variability of individual plants of confectionary sunflower variety SPK during selection of elite for seed-growing

The research was carried out in 2014-2016 at the experimental plot of the All-Russian Research Institute of Oil Crops by the name of V.S. Pustovoit (VNIIMK). The aim of the research is to study the parameters of the individual plants of a confectionary sunflower variety SPK and the patterns of their changes in the process of selection of seed-growing elite at the stage of breeders seed growing. The seed material was evaluated by the seeds yield per a head, oil content (GOST R 8.620-2006) and the thousand-seed weight (GOST 12042-80). As indicators of variability were used average, minimum and maximum values of the trait and the determination of variability range. The change of structure of the initial population and population after the conducted selection was determined by the distribution of individual plants according to the types of manifestation of a trait. It was established that the initial population is highly variable during the selection of individual plants of seed-growing elite of the large-seeded sunflower variety SPK. On average, the variability range over the years of research was 208 g for seeds yield per a head, 122 g for thousand-seed weight and 19.2% for oil content. After the culling of selected individual plants for formation of the nursery of progeny evaluation, the variability range of traits decreased in seeds yield per a head by 9.5%, in thousand-seed weight by 56.4% and in oil content by 30.6%. The intensity of discarding as the ratio of the number of discard plants to the number of plants in the initial population averaged 62.5%. The biggest changes in the population structure under the influence of the selection of the desired genotypes were observed in thousand-seed weight toward its increase. The year conditions had a significant effect on the change of structure of the selected initial population for all the traits studied.