Evaluation of sugar beet diploid hybrids with smooth and round root shape

The sugar beet plant has a conical-shaped root and at harvest the tap-root breaks which remains in the soil. As a result, a significant amount of root yield and consequently sugar content is lost. Furthermore, the field soil remains in the root fissures and is carried with the root to sugar factory. In rhizomania and nematode-infested areas, the soil movement causes the disease wide spread. In this study, the full-sib families 27102 and 27131 developed from an F2 population were used as pollinator and the single cross 231*261 as maternal parent for producing hybrids with smooth and round-shaped roots. The hybrids were produced and evaluated in a randomized complete block design with four replications in Karaj and Moghan. Helix and Rasoul cultivars were used as controls. Based on biplot and cluster analyses of quantitative and qualitative characteristics, the hybrids were divided into five groups. Based on root morphological characteristics (smoothness, form and root uniformity) as well as qualitative and quantitative traits (root yield, sugar yield, sugar content, and purity), the hybrids (261*231)*27102-S1.25, (261*231)*27102-S1.44, and (261*231)*27131-S1.3 with 83.84, 80.68, and 71.28 t ha-1 root yield, respectively, were considered as promising hybrids.