• Journal of Forest and Environmental Science
• /
• v.38 no.2
• /
• pp.102-109
• /
• 2022

This study was conducted to test the significant difference 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. In the spring of 2021, the numbers of female and male flower were counted from 5 to 10 individuals per family in the BSSOs. 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 Spearman's rank correlation was existed between male and female flower production. 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 to supply genetically improved seeds of evergreen oaks, which is one of the backbones of the strategy of carbon sink in the 2050 Carbon Neutrality of Korea Forest Service.

• Korean Journal of Breeding Science
• /
• v.41 no.3
• /
• pp.228-235
• /
• 2009

Growth and branch characteristics of 35 half-sib families were surveyed in a seedling seed orchard of Quercus acutissima at ages 10 and 12. The averages of height, DBH (diameter at breast height), branch height, crown width, branch angle and stem straightness at age 12 were 9.96 m, 14.50 cm, 1.04 m, 6.80 m, $18.82^{\circ}$ and 2.58, respectively. Families of 075 and 052 showed superior height growth and 0511 and 0517 were inferior ones. For DBH growth, 075 and 0413 were best families and 0725 and 0511 were inferior families. Pearson's product moment and Spearman's rank correlation coefficients were all positive for all growth traits except branch angle at ages 10 and 12. This result showed that the families with good height and DBH growth were also superior in stem straightness. In ANOVA, there was a highly significant difference among families in height, DBH, cylindric volume and stem straightness. Branch height, crown width and branch angle were also significantly different among families. Family heritability was higher than individual heritability at ages 10 and 12. Height, DBH and stem straightness were under strong genetic control, showing high family heritability. This implies that high genetic gain could be expected by family selection. Expected genetic gain for each trait was estimated based on the family selection. The highest genetic gain was expected for the traits of branch angle, height and DBH because of the large phenotypic standard deviation and the high family heritability. The growth performance and branch characteristics were weighted by the magnitude of genetic variation and heritability. The weighted values were then subjected to estimate family breeding values. This family breeding value would be applied as a criterion in the genetic thinning of the seed orchard.

• Journal of Korean Society of Forest Science
• /
• v.14 no.1
• /
• pp.1-20
• /
• 1972

The trend and achievements of forest genetics research in abroad were investigated through observation tours and reference work and following facts were found to be important aspects which should be adopted in the forest genetics research program in Korea. Because of world wide recognization on the urgency of taking a measure to reserve some areas of the representative forest type on the globe before the extingtion of such forest type as the results of continuous exploitations of the natural forests to meet the timber demand all over the world, it is urgently needed to take a measure to reserve certain areas of natural stand of Pinus koraiensis, Pinus parviflora, Pinus densiflora f. erectra, Abies koreana, Quercus sp., Populus sp., etc. as gene pool to be used for the future program of forest tree improvement. And the genetic studies of those natural forest of economic tree species are also to be performed. 1. Increase of the number of selected tree for breeding purpose. Because of the fact that the number of plus tree at present is too small to carry out selection program for tree improvement, particularly for the formation of source population for recurrent selection of parent trees of the 2nd generation seed orchard it is to be strongly emphasized to increase the number of plus tree by alleviating selection criteria in order to enlarge the population size of plus trees to make the selection program more efficient. 2. Progeny testing More stress should be placed on carrying out progeny testing of selected trees with open pollinated seeds. And particular efforts are to be made for conducting studies on adult/juvenile correlation of important traits with a view to enable to predict adult performances with some traits revealed in juvenile age thus to save time for progeny testing. 3. Genotype-environment interaction Studies on genotype and environment interaction should be conducted in order to elucidate whether the plus trees selected on the good site express their superiority on the poor site or not and how the environment affect the genotype. And the justification of present classification of seed distribution area should be examined. 4. Seed orchard of broad leaf tree species. Due to the difficulty of accurate comparison of growth rate of neighbouring trees of broad leaf tree species in natural stand, it is recommended that for the improvement of broad leaf trees a seedling seed orchard is to be made by roguing the progeny test plantation planted densely with control pollinated seedlings of selected trees. 5. Breeding for insect resistant varieties. In the light of the fact that the resistant characteristics against insect such as pine gall midge (Thiecodiplosis japonensis U. et I.) and pine bark beetle (Myelophilus pinipera L.) are highly correlated with the amount and quality of resin which are known as gene controlled characteristics, breeding for insect resistance should be carried out. 6. Breeding for timber properties. With the tree species for pulp wood in particular, emphasis should be placed upon breeding for high specific gravity of timber. 7. Introduction of Cryptomeria and Japanese Cypress In the light of the fact that the major clones of Cryptomeria are originated from Yoshino source and are being planted up to considerably north and high elevation in Japan, those species should be examined on their cold resistance in Korea by planting them in further northern part of the country.

• Journal of Korean Society of Forest Science
• /
• v.84 no.3
• /
• pp.356-360
• /
• 1995

Korean white pine(Pinus koraiensis S.et Z.) is one of the important silvicultural species due to its quality timber in addition to edible pine - nut production. Selective breeding method is under progress to improve growth and nut production for this species. This study was carried out to obtain genetic information necessary for establishing advanced generation seed orchard, such as genetic parameters and efficiency of early selection. Open - pollinated cones were collected from 50 plus trees. In the spring of 1986, test plantations were established at 3 different sites with 4 - year - old seedlings. Seedling height was measured from age 5 to 10 in plantations. Genetic and phenotypic correlations based on the log of the ratio of two ages (LAK) were expressed as simple regression with statistical significance($r^2=0.7862$ and 0.8256, respectively). If 20 years is presumed to mature, the most efficient age for early selection is 3 years after planting with efficiency of 1.96.