Abstract
Comparison of the actual sugnr yield of the synthetic varieties with predicted yield based on general combining ability indicated that the optimum number of component strains in the synthetic variety would be about six. But, actual sugar yield was the highest in the three-strain synthetic variety, which was in agreement with the predicted yield based on specific combining ability. The decrease in sugar yield in Syn2 and Syn3 generation was small. The superior synthetic variety can be obtained with smaller number of component strains, in which the specific combining ability might have greater importance.
