深山含笑优树的子代测定及速生优良家系选择

Progeny test and fast-growing superior family selection of Michelia maudiae plus-trees

[目的]探讨深山含笑优树子代生长和表型性状的遗传变异规律,并选育速生优良家系进行推广应用。[方法]采用完全随机区组设计,选择24个深山含笑优树单系实生苗木,营建子代测定林。17年生时,调查树高、胸径、材积、冠幅、枝下高、侧枝粗度、分枝角和通直度等生长和表型性状,并对调查数据进行统计与分析,评选出速生优良家系。[结果]17年生优树子代树高、胸径、材积、冠幅和枝下高等生长性状的均值分别为9.93 m、12.53 cm、0.071 83 m^(3)、2.93 m和2.43 m,侧枝粗度、分枝角和通直度等表型性状的均值分别为1.98、2.34和1.96。各性状的变异系数在11.92%~53.17%之间。树高、胸径、材积和冠幅的家系遗传力分别为0.29、0.33、0.34和0.47;枝下高、侧枝粗度、分枝角和通直度的家系遗传力较小,分别为0.07、0.13、0.05和0.05。树高、胸径、材积、冠幅和侧枝粗度间的相关系数为0.269~0.964,均达极显著正相关。以材积现实增益为指标,选出5个优良家系,入选率为21%。5个优良家系树高、胸径和材积的平均值分别为10.95 m、15.05 cm和0.108 24 m^(3),平均遗传增益分别为2.97%、6.64%和17.23%,材积的现实增益达50.68%。[结论]选出的速生优良家系可作为育种材料保存在种质资源库,并建议通过有性或无性繁殖在南平顺昌及相似立地条件下中试推广。

[Purpose]The aim of the study is to explore the genetic variation of progeny growth and phenotypic traits,and select fast-growing excellent families for promotion and application.[Method]The progeny test stand was built by completely random block design,with seedlings from 24 families of Michelia maudiae plus-trees.The growth and phenotypic traits data of 24 families in the 17-year-old progeny test stand were collected by surveying tree height,DBH,volume,crown width,clear bole height,lateral branch diameter,branching angle and stem straightness.The fast-growing excellent families were selected based on the collected data.[Result]The average height,DBH,Volume,crown width and clear bole height in the 17-year-old progeny test stand were 9.93 m,12.53 cm,0.07183 m^(3),2.93 m and 2.43 m respectively,and the averages of phenotypic characteristics including lateral branch diameter,branching angle and stem straightness were 1.98,2.34,and 1.96 respectively.The variation coefficient of growth and phenotypic traits ranged from 11.92%to 53.17%.The family heritability of height,DBH,volume and crown width was 0.29,0.33,0.34 and 0.47 respectively,and the lower values in family heritability were found in clear bole height,lateral branch diameter,branching angle and stem straightness,which were 0.07,0.13,0.05 and 0.05 respectively.The correlation coefficients among height,DBH,volume,crown width and lateral branch diameter ranged from 0.269 to 0.964,and reached extremely significant positive level.5 fast-growth families were selected based on genetic gain in volume,with a selection rate of 21%through comprehensive comparison and analysis.The averages of height,DBH and volume were 10.95 m,15.05 cm and 0.10824 m^(3) respectively,and the average genetic gains were 2.97%,6.64%and 17.23%,the average real gain of volume was 50.68%.[Conclusion]The selected fast-growing superior families are valuable breeding materials,which should be preserved in the germplasm resource bank and recommended to be pilot tested and applied in the area of Shunchang Nanping and other regions with similar site conditions.