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.