Research Article Impact of Genes and Proportional Contribution of Parental Genotypes to Inheritance of Root Yield and Sugar Content in Diploid Hybrids of Sugar Beet Ivica Stancic, 1 Jelica Zivic, 1 Sasa Petrovic, 1 and Desimir Knezevic 2 1 College of Agriculture and Food Technology Prokuplje, Cirila and Metodija 1, 18400 Prokuplje, Serbia 2 Faculty of Agriculture, University of Pristina, Kosovska Mitrovica-Zubin Potok-Lesak-Kopaonicka bb, 38217 Lesak, Kosovo and Metohija, Serbia Correspondence should be addressed to Desimir Knezevic; deskoa@ptt.rs Received 21 August 2013; Accepted 20 November 2013; Published 28 January 2014 Academic Editors: K. Flisikowski and L. Lanfrancone Copyright © 2014 Ivica Stancic et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Tis paper analyzes the impact of genes and proportional contribution of parental genotypes on the inheritance of root yield and sugar content in diploid hybrids of sugar beet. Te survey included two diploid male-sterile monogerm lines and three single (SC) male-sterile hybrids as maternal components, while three multigerm diploids were used as pollinators. Te partitioning of genotypic variance into additive and dominant components was performed by half sibling (HS) and full sibling (FS) covariance. Te proportional contribution of individual components of crossbreeding (lines, testers, and interactions) was exhibited in the expression of certain characteristics of F 1 generation. Genotypic variance components showed a signifcant efect of nonadditive gene action (dominance) in the inheritance of root yield and sugar content, while the additive efect of genes was less signifcant. Maternal components had a greater proportional contribution to root yield, while lines, pollinators, and their interactions had an equal contribution to sugar content. 1. Introduction Te genetic constitution of sugar beet varieties has changed from multigerm populations to monogerm anisoploid vari- eties and monogerm diploid and triploid hybrids developed due to the occurrence of monogerm, polyploidy, and male sterility. In an analysis of the production values of diploid, triploid, and tetraploid hybrids [1], it was suggested that they can be highly productive, regardless of the type of hybridization. Furthermore, the author noted that the occurrence of hetero- sis was present in all types of hybridization, but it was more evident in diploid and triploid hybrids [2, 3]. When analyzing the results of research on creating monogerm diploid sugar beet hybrids [4], that monogerm diploid sugar beet hybrid hybrid Vitola characterized good combination of genes with impact to high root yield as well and other traits (good tolerance and partial resistance to beet necrotic yellow vein virus (BNYVV) and Cercospora beticola sacc.) and is suitable for cultivation in irrigation systems. Comparative analysis of diploid and triploid sugar beet hybrids was the subject of research of many authors [3, 5–7]. Sugar beet yield is a portion of root dry matter, with higher yields obtained with increasing amount of dry matter produced in the root [8]. Most plant breeders agree that genotype and the environment as well their interaction infu- ence the expression of root yield [9]. Terefore, the highest root yield and quality of sugar were exhibited by some early genotypes in the harvest season [10], while some late harvest genotypes resulted in greater root yield and higher sugar content than earlier harvest genotypes [11]. Te long-sought bolting gene B in the sugar beet crop has been identifed. Early fowering in sugar beet terminates root growth and limits sugar beet yields [12]. Root sucrose content is a highly heritable quantitative trait in sugar beet, with genes acting in an additive fashion. Te genetic investigation conducted Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 580623, 5 pages http://dx.doi.org/10.1155/2014/580623