【目的】评估福建大田28个8年生油杉(Keteleeria fortunei)半同胞家系子代林生长性状的遗传变异,筛选优良家系并估算其遗传增益,用于油杉优良种质的选育及其推广应用。【方法】测定28个油杉半同胞家系子代林的胸径、树高和单株材积等关键生长性状,计算遗传参数(遗传力),通过方差分析检验家系间性状差异的显著性,并采用系统聚类分析法对家系进行类型划分(优良型、中间型、较差型)。【结果】供试油杉家系间生长性状存在丰富变异,胸径、树高、单株材积的平均值分别为8.45 cm、6.21 m、0.022 8 m³,变异系数范围分别为4.96%~43.03%、1.93%~33.44%、9.16%~97.70%。方差分析表明家系间在胸径、树高和单株材积上均存在极显著差异(P<0.01)。树高、胸径和单株材积的家系遗传力分别为0.690 1、0.665 9和0.636 8,表明这些性状受中等至较强的遗传控制。系统聚类将28个家系划分为优良型、中间型和较差型3类。其中,优良型家系的平均胸径、树高和单株材积分别达10.00 cm、7.04 m和0.032 3 m³,较全部家系平均值分别高出18.35%、13.35%和41.68%,较对照群体分别高出21.71%、26.22%和48.23%。在优良型家系中,7、16、4、6、14号家系的平均遗传增益均超过15%,被确定为优良家系。【结论】油杉半同胞家系生长性状存在丰富的遗传变异和极显著的家系间差异,具有较大的遗传改良潜力。筛选出7、16、4、6、14号共5个优良家系,其生长性状显著优于群体平均值及对照,且遗传增益高,可作为油杉良种材料进行申报并推广应用。

【Objective】This study aims to evaluate the genetic variation in growth traits of 28 eight-year-old half-sib families of Keteleeria fortunei in Datian, Fujian Province, screen superior families, and estimate their genetic gains, thereby providing a basis for breeding and popularizing superior germplasm of K. fortunei.【Method】Key growth traits, including diameter at breast height (DBH), tree height, and individual volume, were measured in the progeny forest of 28 half-sib families. Genetic parameters (heritabilities) were calculated. Variance analysis was used to test the significance of trait differences among families, and systematic cluster analysis was employed to classify the families into the excellent, intermediate and poor types.【Result】There was abundant variation in growth traits among the families. The average DBH, tree height and individual volume were 8.45 cm, 6.21 m and 0.022 8 m³, with coefficient of variation ranges of 4.96%-43.03%, 1.93%-33.44% and 9.16%-97.70%, respectively. Variance analysis indicated extremely significant differences (P<0.01) in DBH, tree height and individual volume among families. The family heritabilities for tree height, DBH and individual volume were 0.690 1, 0.665 9 and 0.636 8, respectively, indicating moderate to strong genetic control of these traits. Systematic cluster analysis categorized the 28 families into three types: excellent, intermediate, and poor. The excellent-type families had average DBH, tree height and individual volume of 10.00 cm, 7.04 m and 0.0323 m³, which were 18.35%, 13.35% and 41.68% higher than the overall mean, coefficients of variation were 21.71%, 26.22% and 48.23% higher than the control population, respectively. Within the excellent-type families, families 7, 16, 4, 6 and 14 had average genetic gains exceeding 15% and were identified as superior families.【Conclusion】The growth traits of K. fortunei half-sib families exhibit rich genetic variation and extremely significant differences among families, indicating substantial potential for genetic improvement. Five superior families (7, 16, 4, 6 and 14) were selected based on heritability, cluster analysis and genetic gain evaluation. Their growth traits were significantly superior to the population mean and the control, with high genetic gains, making them suitable for declaration popularization and application as improved germplasm of K. fortunei.