Abstract
We conducted a diallel analysis using an 8 × 8 half-diallel cross among inbred lines of the Japanese radish ‘Sakurajima daikon’ to obtain genetic information concerning its root weight and hollow root for breeding. Root weight showed a high broad-sense heritability and a low narrow-sense heritability. Average degree of dominance was 1.65, suggesting that its root weight is controlled by overdominance. Dominant genes had a positive effect on root weight. Hollow root occurrence expressed by a hollow area ratio showed a low broad-sense heritability and a low narrow-sense heritability. Average degree of dominance was 0.91, suggesting that hollow root occurrence is an incomplete dominant trait similar to a complete dominant trait. Dominant genes had a negative effect on hollow root occurrence. These findings indicate that the F1 hybrid is effective for breeding a bigger root in ‘Sakurajima daikon’. However, hollow root is susceptible to environmental factors, suggesting that we need to consider environmental effects when selecting for hollow root-resistant lines.
