马尾松无性系种子园半同胞子代变异分析和家系选择

以福建省漳平五一林场马尾松无性系种子园自由授粉子代半同胞家系为研究对象,分析其树高、胸径、材积、冠幅、通直度、高径比、冠径比、木材基本密度、管胞长度和宽度、管胞长宽比等性状,发现家系间除管胞长宽比性状差异显著,其余性状均达差异极显著,暗示着马尾松种子园半同胞家系间存在较为丰富的变异,具选育潜力。8年生林分内各性状的家系遗传力以树高性状为最高(0·691),其次是木材基本密度(0·640)。各性状间的相关性分析结果表明,生长量性状的改良可间接改善通直度,且生长量性状与木材基本密度存在显著正相关关系,木材基本密度与管胞长度和宽度不相关。采用10%入选率,发现5年生林分和8年生林分入选家系一致,材积遗传增益分别达19·74%和19·23%,且5年生林分和8年生林分生长量性状的遗传相关极显著,认为马尾松制浆造纸材短轮伐期的初选年龄可确定为5年生;根据性状遗传力的相对大小和典型相关分析的结果,认为马尾松家系选择可适当注重树高生长量指标。以树高和材积为选择指标,按照10%入选率,兼顾材性和种子园内无性系的开花结实情况,筛选出制浆造纸材短轮伐期优良家系12个。

Variation Analysis and Plus Family Selection on Half-Sib Progenies from Clonal Seed Orchard of Pinus massoniana

Variation of traits was analyzed included height, diameter at breast height (DBH), stem volume, crown width, straightness, wood basic density, tracheid length and width of open-pollinated progenies from clonal seed orchard of Pinus massoniana. Traits of growth, stem form and wood quality among families were significant differences that indicated the improvement potential was notable. Heritability of the height growth and wood basic density reached 0.691 and 0.640, respectively. According to the correlation analysis between traits, stem straightness could be improved indirectly when growth traits were improved, growth traits were significant correlated with wood basic density, and wood basic density was not significantly correlated with length and width of tracheid. Under the selection ratio of 10 percent, genetic gain was 19.74 and 19.32 percent respectively, and selected families from the progeny test stands at age of 5 years and 8 years were the same. And genetic correlation of height, DBH and stem volume was significant at level of 0.01. These all showed that selection of the short rotation of P. massoniana for pulp and paper use would be efficient for trees of 5-year-old. Comparing the heritability of all the traits and with the result of canonical correlation analysis, the trait of height growth could be the most important index for selection. Consideration was given to wood quality of all the families, and flowering and fruit setting of the clones in seed orchard, twelve plus families were selected under 10 percent selection ratio of height growth and stem volume.