Priority technologies for developing new highly productive varieties of spring bread wheat in the Middle Urals

The study has been carried out at the FSBSI «Ural Federal Agrarian Research Center of the Ural Branch of the Russian Academy of Sciences» on the fields of the Krasnoufimsk Breeding Center in 2019–2021. The purpose was to develop new highly productive varieties of spring bread wheat adapted to the climatic conditions of the Middle Urals using parental forms with high breeding indices in hybridization. There has been given a characteristic of the earlymaturing variety ‘Ekstra’ and middle-early maturing ‘Nitsa’ and their parents, namely, ‘Omskaya 35’ and ‘Iren’, ‘Ekaterina’ and ‘Krasnoufimskaya 100’, according to such breeding indices as Mexican, Canadian, Poltava, attraction, productivity, potential head productivity, intensity, micro-distribution, linear head density, grain filling. There has been shown that the productivity advantage of the variety ‘Ekstra’ over the variety ‘Iren’ was 0.37 t/ha (11.1 %) and over thevariety ‘Omskaya 35’ it was 0.31 t/ha (9.1 %). The variety ‘Ekstra’ has combined the high values of six breeding indices from the middle maturing variety ‘Omskaya 35’ and exceeded both parents in the studied indices. The productivity advantage of the variety ‘Nitsa’ was 0.52 t/ha (19.2 %) over the variety ‘Ekaterina’ and over the variety ‘Krasnoufimskaya 100’ it was 0.40 t/ha (14.2 %). It has combined the high values of four indices from the variety ‘Ekaterina’, six from the variety ‘Krasnoufimskaya 100’ and significantly exceeded the parental varieties according to such indices as Poltava, Mexican, microdistribution, attraction, grain filling, intensity. There has been identified a high positive correlation between grain productivity and attraction indices (r = 0.761) and Mexican (r = 0.864), an average positive correlation between indices of intensity (r = 0.601), potential head productivity (r = 0.507), grain filling (r = 0.333). The results have showed that involving parents with high values of breeding indices into hybridization could contribute to the development of new highly productive varieties of spring wheat.