Abstract
We estimated genetic parameters for basal bending due to snow pressure damage in sugi (Cryptomeria japonica). Using 19 factorial mating designs in 13 progeny trials, we analyzed 160 snow-resistant trees and 23 plus trees. Because the plus trees could be considered to be resistant against snow pressure, they were used as materials together with snow-resistant trees in this study. We measured basal bending at the age 10 of the trials. The results showed that the ratio of additive genetic variance to the total genetic variance was high. Therefore, we concluded that additive genetic variance can be used effectively in the genetic improvement program to reduce basal bending by providing open-pollinated seeds from seed orchards. The mean heritability was 0.11 (range, 0∼0.27). The genetic parameters calculated in this study were estimated from snow-resistant populations. Thus, the parameters should be used (e.g., to estimate the genetic gain) for finding effective and efficient ways to breed against basal bending.
