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영어

This study was conducted to test the statistical significance of fertility variation among families and to select superior families for acorn production in the breeding seedling seed orchards (BSSOs) of Quercus acuta and Quercus glauca. The seed orchards were located in Jeju island and established by seedlings raised from selected parents for genetic testing in 2006. Re-selection from the BSSOs would be necessary to establish advanced generation seed orchards in order to expand the afforestation of evergreen warm broad-leaved trees in response to climate change. In the spring of 2021, the numbers of female and male flower were counted from ten individuals per family in the BSSOs. The female flowers were counted individually over the entire crown, but the number of male flowers was estimated by multiplying the average number of flowers per branch by the total number of branched bearing flowers. To test statistical significance of which parameter is not satisfied through the normality test, we used a nonparametric analysis. Correlation analysis was performed to quantify the association between female and male flower production. As the results, the significant difference of flower production among families was found in both seed orchards. The averages of female flower production were 65.3 and 181.9 in Q. acuta and Q. glauca. The positive rank correlation was existed between male and female flower production in the BSSOs. Broad-sense heritability on female and male flower production were 0.191 and 0.147 in Q. acuta, and 0.285 and 0.068 in Q. glauca, respectively. Sexual asymmetry (e.g., maleness index) between female and male, and contribution variation among families (e.g., parental balance) were analyzed to find reasonable alternatives in the management of seed orchards. Effective population size of seed crops was predicted as a concept of status number. Loss of gene diversity (accumulation of group coancestry) would not be alarming in the BSSOs. Our results would be helpful to select breeding materials for establishing new seed orchards and supplying genetically improved seeds of evergreen warm tree species, which is one of the backbones of strategy of carbon sink in the 2050 Carbon Neutrality of Korea Forest Service.