日本落叶松无性系管胞力学性质的遗传变异

对4个12年生的日本落叶松无性系幼龄材早材单根管胞进行了拉伸实验。结果表明:日本落叶松无性系幼龄材早材单根管胞拉伸弹性模量、拉伸强度和断裂伸长率的均值分别为11.44 GPa、616.59 MPa和6.54%,相应的变异系数为26.97%、26.26%和23.17%。方差分析表明日本落叶松幼龄材早材单根管胞拉伸弹性模量和管胞断裂伸长率在无性系间差异极显著(0.01水平),拉伸强度在无性系间差异不显著;株内早材单根管胞拉伸弹性模量、拉伸强度和管胞断裂伸长率在年轮间差异显著。对日本落叶松无性系幼龄材早材单根管胞拉伸力学性能进行遗传参数估计,单根管胞弹性模量和断裂伸长率的重复力分别是0.79和0.57,属于中度到强度遗传控制,无性系早期选择及材性遗传改良潜力较大。

A Study on the Genetic Variation in the Mechanical Properties of Single Tracheids of Japanese Larix

The mechanical properties of single tracheids sampled from the juvenile wood of four 12-year-old Japanese Larix clones were examined by using tensile testing. The results revealed that the modulus of elasticity, tensile strength and breaking elongation of single tracheids of different clones were 11.44 GPa, 616.59 MPa and 6.54%, respectively, with the corresponding variation coefficient being 26.97%, 26.26% and 23.17%. The modulus of elasticity and breaking elongation of single tracheids were significantly different (at 0.01 level) among different clones of Japanese Larix, whereas the tensile strength showed insignificant difference. The modulus of elasticity, tensile strength and breaking elongation of single tracheids showed significant differences among different growth rings within a single tree. The repeatability of modulus of elasticity and breaking elongation of Japanese Larix clone were 0.79 and 0.57, respectively, indicating these two mechanical property indexes of tracheids being under moderate to strong genetic control. These results indicate that there are great potentials for early clone selection and genetic improvement in wood properties of Japanese Larix clones.