Evaluation of Sugar Beet (Beta vulgaris L.) Genotypes in Terms of Morphological and Quality Traits

Abstract

In this study, 187 sugar beet (Beta vulgaris L.) genotypes obtained from the United States Department of Agriculture (USDA) gene bank and five commercial cultivars (Serenada, Varias, Evelina, Jaguar, Balaban) were evaluated in terms of morphological and quality traits. Agronomic characters such as root-shoot yield, sugar content, leaf yield, and sugar yield were examined, and the data were analyzed using coefficients of variation and principal component analysis (PCA). The results revealed significant morphological and quality differences among the genotypes. According to PCA, the first four principal components explained 100% of the total variation, with the first three components accounting for 78.55% of the genetic diversity. The first component reflected the relationship between sugar content and root yield, the second explained the contrast between leaf yield and sugar yield, while the third highlighted differences between total yield and sugar content. Furthermore, dendrogram analysis demonstrated that commercial cultivars and USDA genotypes clustered separately, indicating a broad genetic diversity. The findings emphasize the critical role of parent selection in sugar beet breeding. Particularly, high-sugar cultivars such as Serenada and Varias, when crossed with high root or leaf yield cultivars such as Balaban and Jaguar, may generate superior combinations through heterosis, enhancing both yield and quality. Moreover, USDA genotypes, which clustered distantly from commercial varieties, were identified as a valuable source of genetic variation. In conclusion, this study revealed a substantial genetic diversity in yield and quality parameters among sugar beet genotypes, highlighting their potential use in breeding programs aimed at developing new cultivars with higher industrial efficiency and superior morphological traits.