毛红椿生长、心材和材性性状遗传分析及家系选择

Genetic Analysis and Family Selection of Growth,Heartwood and Wood Traits for Toona ciliata var.pubescens

[目的]通过研究15年生毛红椿家系试验林的生长、心材和材性性状的遗传变异规律,选择速生且优质的毛红椿优良家系。[方法]以浙江开化县林场的15年生毛红椿家系试验林为材料,测定其树高、胸径、材积、心材率、心材材积和木材基本密度,进行方差、相关和主成分等分析。[结果]毛红椿家系间树高、胸径、材积、心材率、心材材积和木材基本密度等6个生长、心材和材性性状的差异均达极显著水平,并有较高的遗传稳定性,但冠幅和枝下高在家系间差异不显著。表型相关和遗传相关分析表明,毛红椿胸径与心材材积和材积之间呈显著正相关,通过对胸径的选择能间接实现对材积和心材材积的选择。主成分分析结果显示,材积、心材材积、胸径、树高和心材率等5个性状代表了毛红椿的品质和经济性状,对前两个主成分PC1和PC2的贡献率较高。通过构建材积、心材率、心材材积和木材基本密度等4个性状的综合指数选择方程,对毛红椿所有家系进行综合评价,选出了2个符合改良条件的优良家系,其材积、心材率、心材材积和木材基本密度获得的平均遗传增益分别为:52.84%、0.49%、66.23%和2.13%。[结论]毛红椿育种目标应重点围绕生长和心材性状,而冠幅和枝下高遗传力较小且家系间差异不显著,不适宜作为遗传改良的目标。

[Objective]By studying the genetic variation of the growth,heartwood and wood character of 15 year old T.ciliata var.pubescens families for selecting the fast growing and high quality families of T.ciliata var.pubescens.[Methods]Based on A 15-year old family test forest of T.ciliata var.pubescens in Kaihua forest farm,Zhejiang Province,the tree height,DBH,volume,heartwood percentage,heartwood volume and wood basic density were measured,and the variance,correlation and principal component analysis were performed.[Results]There were significant differences in tree height,DBH,wood volume,heartwood percentage,heartwood volume and wood basic density among families,and heartwood and wood properties had high genetic stability,but there were no significant differences in crown width and height at crown base among families.Phenotypic and genetic correlation analysis showed that there was a significant positive correlation between DBH and heartwood volume and volume,and DBH could indirectly realize the selection of volume and volume of heartwood.The results of principal component analysis showed that volume(V),heartwood volume(Vh),diameter at breast height(D),tree height(H)and heartwood ratio(Rh)represented the quality and economic traits of T.ciliata var.pubescens,and contributed significantly to the first two principal components,PC1 and PC2.By constructing a comprehensive index selection equation for four characters:volume,heartwood percentage,heartwood volume,and wood basic density,two excellent families meeting the improvement conditions were selected.The average genetic gains of volume,heartwood percentage,heartwood volume and wood basic density were:52.84%,0.49%,66.23%and 2.13%.[Conclusion]The breeding objectives of T.ciliata var.pubescens should focus on growth and heartwood traits,but heritability of crown width and height at crown base are small and the differences between families are not significant,which indicates that crown width and height at crown base are not suitable targets for genetic improvement.