【摘要】 以韶关地区尾叶桉Eucalyptusurophylla103个无性系为研究材料,采用混合线性模型对尾叶桉7月生树高（H₇）、18月生胸径(D₁₈)、18月生材积(V₁₈)和18月生耐寒性指数(C₁₈)性状进行遗传参数估算,同时通过综合指数选择法对18月生尾叶桉无性系进行早期选择。结果表明:尾叶桉无性系早期生长较好,D₁₈、V₁₈和C₁₈平均值分别为5.4 cm、1.30 m³和0.37;尾叶桉H₇、D₁₈、V₁₈和C₁₈在无性系间的方差达到了显著或极显著水平,方差分量在0.05～1.01之间,剩余方差分量介于0.02～1.76之间,其无性系重复力在0.45～0.94之间,单株重复力在0.14～0.78之间,说明尾叶桉无性系的大部分性状不仅受遗传影响,还受到环境因子的影响。除C₁₈与生长性状相关系数不显著外,生长性状间表型与遗传相关系数均达到极显著水平,相关系数达0.8以上。以18月生生长与耐寒性状进行早期选择,综合评选9个优良无性系ZQUA9、ZQUA22、ZQUA44、LDUB94、ZQUC14、ZQUC17、ZQUA34、LDUC1和ZQUD1,入选无性系的H₇、D₁₈和C₁₈均值分别比对照（DH3229）高出0.32 m,0.68 cm和0.39,达13.18%、13.01%和136.27%。尾叶桉生长性状在无性系间存在显著差异,且具有较高的遗传稳定性。更多还原

【Abstract】 The clones with high quality and cold tolerance were selected based on the genetic evaluation of Eucaphylla urophylla clone determination forest in Shaoguan. Using103 E. urophylla clones as research materials,the genetic parameters of 7-month-old height（H₇）, 18-month-old diameter at breast height(D₁₈), 18-month-old volume(V₁₈) and 18-month-old cold tolerance index(C₁₈) were estimated using mixed linear model, and the early selection of E. urophylla was carried out by using comprehensive index selection method. The average values of D₁₈, V₁₈ and C₁₈ were 5.4 cm, 1.30 m³ and 0.37, respectively, which showed that the clone trial of E. urophylla grew well; The variance of clones for H₇, D₁₈, V₁₈ and C₁₈ had significant or extremely significant levles, and the genetic variance components ranged from 0.05 to 1.01, and the residual variance components ranged from 0.02 to 1.76. The clonal repeatability ranged from 0.45 to 0.94, and the individual repeatability ranged from 0.14 to 0.78,respectively. It was noticed that most traits of E. urophylla clones were affected by not only genetic factors, but also environmental factors. Except that C₁₈ had no significant correlations with growth traits, the phenotypic and genetic correlations between growth traits were significant, and the coefficients were above 0.8. Nine excellent clones（ZQUA9, ZQUA22, ZQUA44, LDUB94, ZQUC14, ZQUC17, ZQUA34, LDUC1 and ZQUD1） were selected based on the growth and cold tolerance of 18-month-old. The mean values of H₇, D₁₈ and C₁₈ of excellent clones were 0.32 m, 0.68 cm and 0.39 higher than the control（DH3229）, and were 13.18%, 13.01% and 136.27%,respectively. Growth among clones were significant difference that could be inheritance stably. Nine superior clones were selected preliminarily, which could provide references for further breeding of Eucalyptus clones.更多还原