8年生亚美马褂木无性系生长和材性变异与选择

Growth and Wood Traits Variation and Selection of Superior Clones of Eight-year-old Liriodendron sinoamericanum

  • 摘要: 以亚美马褂木120个8年生无性系为研究材料,估算各性状遗传参数,探究亚美马褂木无性系生长和材性遗传变异规律,筛选生长和木材基本密度兼优的无性系。结果表明:生长和木材基本密度在无性系间存在显著或极显著差异。遗传变异系数和无性系重复力大小在性状间变化趋势一致,以单株立木材积最大,胸径、冠幅、树高居中,木材基本密度最小。无性系各性状具有较强的遗传稳定性,其无性系重复力显著大于个体重复力。树高、胸径、冠幅、单株立木材积间的表型相关和遗传相关均呈现出极显著相关性,但木材生长和木材基本密度间相关性不显著,表明两者在遗传上可能具有独立性;基于选择指数筛选出15个生长和木材基本密度兼优的无性系,入选率为12.40%,选择强度为1.73。与参试群体均值相比,入选优良无性系的树高、胸径、冠幅、单株立木材积和木材基本密度平均现实增益分别为22.25%、29.45%、28.64%、74.14%和11.04%,平均期望遗传增益分别为13.39%、18.94%、18.53%、52.56%和6.09%。可见参试无性系表现出显著的变异和选择潜力,每个性状主要受遗传因素控制,表明遗传控制具有很强的稳定性和独立性。

     

    Abstract: Using 120 eight-year-old clones of Liriodendron sinoamericanum as research material, genetic parameters for various traits were estimated to explore patterns of genetic variation in growth and wood properties among L. sinoamericanum clones and to select clones with excellent growth performance and wood basic density. The results showed significant or extremely significant differences among clones in growth traits and wood basic density. The genetic variation coefficient and clonal repeatability followed a consistent pattern across traits, with individual tree volume the largest, followed by diameter at breast height, crown width, and tree height, and wood basic density the smallest. The clones exhibited strong genetic stability for all traits, with clonal repeatability significantly greater than individual repeatability. Phenotypic and genetic correlations among tree height, diameter at breast height, crown width, and individual tree volume were extremely significant. However, correlations between wood growth traits and wood basic density were not significant, suggesting they may be genetically independent. Fifteen clones demonstrating excellent growth performance and wood basic density were identified, resulting in a selection rate of 12.40% and a selection intensity of 1.73. These selected clones showed average realized gains compared to all tested clones: 22.25% for tree height, 29.45% for diameter at breast height, 28.64% for crown width, 74.14% for individual tree volume, and 11.04% for wood basic density. The expected genetic gains were 13.39%, 18.94%, 18.53%, 52.56%, and 6.09% respectively. Overall, the clones displayed considerable variation and strong potential for selection. Each trait was mainly influenced by genetic factors, indicating high stability and independent genetic control.

     

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