杉木无性系木材密度遗传变异及其与生长性状的相关性

The Genetics and Variation of Wood Density in Chinese Fir Clones and Its Interaction to the Growth Characters

对3块7～10年生杉木无性系测定林的木材密度遗传变异情况及其与生长性状的相关性进行了研究,结果表明:无性系间木材密度存在真实的遗传差异,为无性系木材密度做出贡献的各因素中,有50%～60%来自于遗传因素;无性系木材密度的重复力介于0.829～0.911之间,遗传变异系数介于4.86%～6.98%之间,木材密度最大值与最小值之比介于1.25～1.47之间,无性系重复力较高,相对生长性状而言遗传变异及无性系间的差异较小;木材密度与树高、胸径、材积的表型、遗传和环境的相关性均呈现负相关,有近80%的木材其密度与生长性状的表型、遗传的相关性达到显著或极显著负相关水平,这表明选择生长性状与材质兼优的无性系相当困难.讨论提出了杉木优良无性系选择分两步进行的建议.

The genetics and variation of wood density and its interaction to the growth character of three 7～10 year-old clone test plantations of Cunninghamia lanceolata were studied in Guangdong Province. The results show as follows. There are genuine genetic differences in wood density among the studied clones and 50 to 60% of the contributing factors to wood density are from the heredity elements. The repeating ability of wood density in the clones is from 0.829 to 0.911 and the genetic variation coefficient of wood density is from 4.86% to 6.98%. And in each test plantation, the wood density ratio between the maximum clone and the minimum clone is from 1.25 to 1.47. All these indicate that the repeating ability is rather high; that the genetic variation and the differences among the clones are small compared to the growth character; and that the correlations of wood density to height, D.B.H, volume phenotype, genetics and environment are all negative. Furthermore, there are 80% of the clones that have significant negative correlations described above. This shows that it is quite difficult to select excellent clones according to both growth and wood quality. Therefore, it has been suggested in this discussion that in order to select excellent clones of Cunninghamia lanceolata, the growth character should be considered the first factor and the wood quality the second.