琼西南5年生柚木无性系生长性状遗传变异分析

Analysis on genetic variation of growth traits of 5 years old Tectona grandis L.f.clones at southwestern region of Hainan

【目的】研究柚木无性系生长性状遗传变异和年度相关性,早期选育速生优良无性系。【方法】采用6株单行小区、6次重复的完全随机区组设计,对海南省乐东县15个柚木无性系大田测定林造林后1~5 a的保存率和生长指标进行方差分析、邓肯多重比较、遗传参数估算和相关性分析,并通过主成分分析,计算综合得分,在此基础上选出速生优良无性系。【结果】造林后5 a,柚木无性系间保存率差异显著(P<0.05),无性系保存率为61.50%~83.33%,平均保存率为73.26%,无性系7509的保存率最高,为83.33%;造林后5 a,柚木无性系间树高、胸径和单株材积均呈极显著差异(P<0.001),其平均值分别为5.29 m、7.29 cm和16.34 dm^(3),以无性系74_12最高,其树高、胸径和单株材积的平均值分别为6.12 m、9.11 cm和27.45 dm^(3);造林后1~5 a柚木无性系的树高、胸径和单株材积的变异系数分别为15.02%~19.35%、13.65%~20.14%和31.04%~41.01%,重复力分别为0.697~0.858、0.819~0.847、0.751~0.854;柚木无性系生长性状的年度相关性呈显著水平(P<0.05)。【结论】柚木无性系生长性状间存在稳定的遗传变异,有较高的遗传改良潜力;为琼西南地区筛选出柚木速生无性系74_12、7114和7509,入选无性系的树高、胸径、单株材积和保存率的平均值分别为35.77 m、8.07 cm、21.27 dm和74.61%,分别比对照提高了19.21%、23.60%、75.60%和3.40%。选择后树高、胸径和单株材积的现实增益为9.07%、10.69%和30.20%,遗传增益为7.71%、9.09%和25.67%,入选的3个无性系可作为后续柚木育种和推广的优良材料。

【Objective】To study the genetic variation and annual correlation of growth traits in Tectona grandis L.f.clones,and select fast growing excellent clones in the early stage.【Method】Using a completely randomized block design with 6 single row plots and 6 replicates,we conducted variance analysis,Duncan multiple comparisons,genetic parameter estimation,and correlation analysis on the preservation rate and growth indicators of 15 T.grandis L.f.clones in the field after afforestation in Ledong county,Hainan province.Through principal component analysis,comprehensive scores were calculated,and on this basis,fast growing excellent clones were selected.【Result】At 5 years after afforestation,there was a significant difference in the preservation rate between clones of T.grandis L.f.(P<0.05).The preservation rate of clones ranged from 61.50%to 83.33%,with an average preservation rate of 73.26%.Clone 7509 had the highest preservation rate of 83.33%;At 5 years after afforestation,there were extremely significant differences(P<0.001)in tree height,diameter at breast height,and individual volume among T.grandis L.f.clones,with an average of 5.29 m,7.29 cm,and 16.34 dm^(3),respectively.Clones 74_12 was the highest,with the average values of tree height,diameter at breast height,and individual volume of 6.12 m,9.11 cm,and 27.45 dm^(3),respectively;At 1-5 years after afforestation,the coefficient of variation of tree height,diameter at breast height,and individual volume of T.grandis L.f.clones ranged from 15.02%to 19.35%,13.65%to 20.14%,and 31.04%to 41.01%,respectively.The repeatability ranged from 0.697 to 0.858,0.819 to 0.847,and 0.751 to 0.854,respectively;The annual correlation of growth traits of T.grandis L.f.clones showed a significant level(P<0.05).【Conclusion】There is a stable genetic variation among the growth traits of T.grandis L.f.clones,which has a high potential for genetic improvement;The fast-growing clones 74_12,7114,and 7509 of T.grandis L.f.were selected for the southwestern region of Hainan.The average values of tree height,diameter at breast height,individual volume,and preservation rate of the selected clones are 5.77 m,8.07 cm,21.27 dm^(3),and 74.61%,respectively,which are 19.21%,23.60%,75.60%,and 3.40%higher than the control.The actual gains in tree height,diameter at breast height,and individual volume after selection are 9.07%,10.69%,and 30.20%,while the genetic gains are 7.71%,9.09%,and 25.67%.The three selected clones can be used as excellent materials for subsequent T.grandis L.f.breeding and promotion.