Study on Genotypic Variance Components of Agronomic Traits in Monogerm Germplasm of SugarBeet

In order to investigate genetic variance components of agronomic traits in sugar beet, five o-type monogerm lines were crossed with 15 CMS monogerm lines on the basis of design II and 75 F1 hybrids were obtained. 75 hybrids were divided to three sets with 25 hybrids in each set and were evaluated in a randomized complete block design with four replications in Abdol-Rasoul Motahhari Research Station, Karaj. In this study, root yield, sugar yield, white sugar yield, sugar content, white sugar content, potasium, sodium, nitrogen, potasium/ sugar content ratio, sodium/ sugar content ratio, nitrogen/ sugar content ratio, alkalinity, purity, molases, root length, root diameter, crown length and crown diameter were calculated. Genetic analysis showed the significant efect ofmales for sugar content, white sugar content and nitrogen traits at 1% probability level and for sodium and purity triats at 5% probability level. Males×Females was significant for white sugar content at 1% probability level and for white sugar content, sugar yield and sugar content in 5% probability level. Additive genetic variance was only significant at 10% probability level for purity and at 12 % probability level for sugar content, white sugar content and nitrogen. Also, dominance variance was significant for white sugar content at 5% probability level and for white sugar yield and sugar content at 12% probability level. Narrow sense heritability of sugar content, white sugar content and nitrogen was significant at 12 % probability level and the rest of traits had low narrow sense heritability. Results of this study revealed that the amount of additive and dominance variances in monogerm germplasm of sugar beet was not large and for impoving genetic basis ofagronomic traits in monogerm gelmplasm, we should use new monogerm germplasm or multigerm genotypes.