Study on the relation between agronomic traits and root morphology and determination of traits affecting root yield and sugar content in monogerm germplasm of sugar beet

To determine the most important traits affecting root yield and sugar content in monogerm germplasm of sugar beet, 75 monogerm F1 hybrids were evaluated in three separate experments conducted in randomized complete block desing (RCB) with four replications at Abdo–al–Rasoul Research Farm, Karaj in 2004. Root yield, root length, root diameter, crown height, crown diameter, sugar content, α–amino–nitrogen, sodium, potassium, K/Na ratio, K/SC ratio, N/SC ratio, alkality coefficient, white sugar yield, molasses, white sugar content, sugar yield, root uniformity, growth score and purity were measured. Mean of treatments were used for statistical analysis. Factor analysis by principal component methods, revealed that all of the traits could interpret in three factors, white sugar content, root yield and morphological charactors of root. Stepwise regression analysis for root yield as dependent variable ad other traits as independent variables, showed the importance of sugar yield, sugar content, white sugar yield, alkality coefficient, root diameter and crown lenghth. The relationships among root yield with sugar yield, white sugar content and root diameter were positive. Also, white sugar content, K/Na ratio and purity contributed largely to the sugar content. Canonical correlation revealed that increasing of root length and diameter and decreasing of crown diameter accompanied by decreasing root impurities.