Breeding value of multi-sprout pollinator lines of different inbreeding generations as parental components of sugar beet hybrids on а CMS basis

Abstract

Aim. Creation of combination-capable lines of multi-sprout pollinators of sugar beets of different levels of homozygosity, establishment of criteria for their selection based on basic productivity, reproductive capacity and hybridization potential at various stages of the selection process for the formation of parental components of hybrids on the cytoplasmic male-sterile (CMS) basis. Methods. Field (experiments, phenological observations), laboratory (to determine sugar content), measuring and weighing (to determine the crop structure), statistical (mathematical processing of research results). The research was carried out at the Tobacco Research Station of the National Scientific Center "Institute of Agriculture of the National Academy of Agrarian Sciences" in the laboratory of sugar beet breeding during the 2015–2021. The starting material was three hybrid multi-sprout populations of sugar beet Um. 17/02-1705, Um. 21/01-33 and Um. 14/05-752. Linear materials were obtained by the inbreeding method. Results. It was established that the lines of multi-sprout pollinators of sugar beets of the second-third generations of inbreeding (I2-I3) are characterized by the highest productivity. The yield of root crops exceeded the standard by 8.1–9.3%, sugar content by 8.6–8.8% and sugar collection by 16.5–17.9%. As the depth of inbreeding increases, the quality of pollen deteriorates sharply. If in the lines of the first generation of inbreeding (I1), the fertility of pollen in plants of of multi-sprout pollinators was 95.1%, then in the lines of the fifth generation (I5) it decreased to 31.0%. The number of non-viable pollen grains in them was 72.2%, seed germination was 29%. Experimental hybrids with the best performance were obtained by using as pollinators lines of the second to third generations of inbreeding. According to the complex characteristic "sugar collection", they exceeded the group standard by 19.7–21.3%. Conclusions. It has been established that for the formation of line materials of sugar beet multi-sprout pollinators, as parent components of hybrids on а CMS basis, the main criterias for the selection of valuable plant genotypes, in addition to the hybridization potential, are high level of their basic productivity and reproductive capacity. The best experimental sugar beet hybrids were obtained by using lines of multi-sprout pollinators of the second to third inbreeding generations.