Genetic analysis of root adaptive traits in sugar beet

Genetic improvement of sugar beet requires better knowledge of genetic basis of root adaptive traits to nutritional stress. This study was conducted to determine combining ability and heritability for morphological and physiological root traits involved in nutrient acquisition in a diallel set of crosses of 5 sugar beet genotypes. Total root length, root surface area, number of root tips, glucose and fructose concentration in the root tips, and sulfate uptake rate were evaluated after sulfate deprivation on six-teen day old seedlings grown under hydroponic conditions. Significant differences were observed among genotypes for the morphological and physiological traits evaluated, and such traits were significantly correlated with the productivity. The genetic analysis showed that general and specific combining ability effects were significant for all traits, with a predominance of additive gene effects. All traits exhibited high coefficients of heritability, suggesting their response to the selection process. The inheritance of the investigated traits could be considered in breeding programs aimed at increasing sugar yield under nutritional stress.