【目的】通过柳杉种子园半同胞子代测定,阐明家系生长性状的遗传变异、性状相关规律,评价参试家系在试验地点的生长表现和育种价值,选择速生优良家系和单株进行推广应用。【方法】2014年在福建省福鼎后坪国有林场营建柳杉种子园半同胞子代试验林,于试验林1~7年生时,对51个家系每木调查树高、胸径和冠幅等生长量指标并建立数据库,分析家系生长性状的遗传变异和相关规律,估算家系及单株遗传力,对参试家系和单株进行评价和选择。【结果】试验林7年生时,树高、胸径、冠幅和材积的平均值分别为4.51 m、6.68 cm、2.09 m和0.011 10 m³,冠幅变异系数为16.75%,而5年生材积变异系数达101.60%,参试家系的适应性较好且生长性状存在丰富的变异。1~7年生试验林的树高、胸径和材积等生长性状在重复和家系间的差异均达极显著水平,生长环境和家系本身的基因型对柳杉早期生长均有显著影响。试验林1~7年生的家系遗传力为0.465~0.649,单株遗传力为0.223~0.507;在家系层次上,生长表现受中等程度之上的遗传控制;在个体层次上,生长表现受较弱程度的遗传控制。生长性状间的相关系数为0.35~0.97,生长性状的表型相关均达极显著水平。经综合评价和估算遗传增益,选出速生家系8个,树高、胸径和材积等遗传增益的平均值分别为5.53%、7.89%和22.95%;选出速生个体35个,其树高、胸径和材积的平均遗传增益分别为23.11%、27.84%和96.77%。【结论】参试柳杉家系生长表现较好,生长性状遗传变异丰富,选择的速生优良家系和个体将为试验地区柳杉人工造林提供良种材料,为构建柳杉第2代育种群体和提升柳杉遗传改良水平提供育种材料。

【Objective】The families’ growth performance and breeding value are evaluated through the Cryptomeria japonica seed orchard half-sib progeny test to clarify the genetic variation and the correlation laws of growth traits. Fast-growing, excellent families and individuals are selected for promotion and application. 【Method】 The growth traits data of 51 tested families were continuously collected by observing and surveying the seed orchard half-sib progeny test forests established at the Houping State Forest Farm of Fuding in Fujian Province in 2014. The individual and family heritability was estimated, and the growth performance of the tested families was evaluated by analyzing the genetic variation and correlation laws of growth traits based on data from one, three, five, six, and seven years of age. 【Result】The average height, diameter at breast height (DBH), crown width, and volume were 4.51 m, 6.68 cm, 2.09 m, and 0.011 10 m³, respectively. The variation coefficient of growth traits ranged from 16.75% to 101.60% at seventh years of age. The tested families demonstrated good adaptability and abundant variations in growth traits. Significant differences in height, DBH, and volume among families and repetitions across the one to seven year age range were observed. The growth performance of the forest was primarily influenced by the family genotype and site conditions. Family heritability of growth traits ranged from 0.465 to 0.649, while individual heritability ranges from 0.223 to 0.507. Growth performance was controlled by a moderate degree of genetic influence at the family level and a weaker degree at the individual level. The correlation coefficients among tree height, DBH, crown width, and volume ranged from 0.35 to 0.97 over one to seven years. Positive correlations among growth traits were highly significant. Eight fast-growing families were selected through the estimation of genetic gains and a comprehensive comparison. The average genetic gains of tree height, DBH and volume were 5.53%, 7.89% and 22.95%, respectively. In addition, 35 fast-growing individuals were selected, with average genetic gains of tree height, DBH and volume of 23.11%, 27.84%, and 96.77%, respectively. 【Conclusion】The tested families grow well at the sites, and the genetic variation in growth traits is abundant. The selected families and individuals can be promoted and applied in Fuding and similar site conditions in Fujian Province. This provides excellent genetic material for C. japonica afforestation, significantly increasing the afforestation area of improved varieties and enhancing the economic and social benefits of C. japonica plantations. In addition, it supports the construction of the second-generation breeding population of C. japonica and the advancement of its genetic improvement level.