PDF(Pubmed)
Abstract：
Twisted trunks are not uncommon in trees, but their effects on tree growth are still unclear. Among coniferous tree species, the phenomenon of trunk distortion is more prominent in Pinus yunnanensis. To expand the germplasm of genetic resources, we selected families with excellent phenotypic traits to provide material for advanced generation breeding. The progeny test containing 93 superior families (3240 trees) was used as the research material. Phenotypic measurements and estimated genetic parameters (family heritability, realistic gain and genetic gain) were performed at 9, 15, and 18 years of age, respectively. The genetic evaluation yielded the following results (1) The intra-family variance component of plant height (PH) was greater than that of the inter-family, while the inter-family variance components of other traits (diameter at breast height (DBH), crown diameter (CD), height under branches (HUB), degree of stem-straightness (DS)) were greater than that of the intra-family, indicating that there was abundant variation among families and potential for selection. (2) At half rotation period (18 years old), there was a significant correlation among the traits. The proportion of trees with twisted trunks (level 1-3 straightness) reached 48%. The DS significantly affected growth traits, among which PH and DBH were the most affected. The volume loss rate caused by twisted trunk was 18.06-56.75%, implying that trunk distortion could not be completely eliminated after an artificial selection. (3) The influence of tree shape, crown width, and trunk on volume increased, and the early-late correlation between PH, DBH and volume was extremely significant. The range of phenotypic coefficient of variation, genetic variation coefficient and family heritability of growth traits (PH, DBH, and volume) were 44.29-127.13%, 22.88-60.87%, and 0.79-0.83, respectively. (4) A total of 21 superior families were selected by the method of membership function combined with independent selection. Compared with the mid-term selection (18 years old), the accuracy of early selection (9 years old) reached 77.5%. The selected families\' genetic gain and realistic gain range were 5.79-19.82% and 7.12-24.27%, respectively. This study can provide some useful reference for the breeding of coniferous species.
摘要：
扭曲的树干在树上并不少见，但它们对树木生长的影响仍不清楚。在针叶树物种中，云南松树干变形现象较为突出。扩大种质遗传资源,我们选择了具有优异表型性状的家庭，为高级一代育种提供材料。以含有93个优良家系(3240棵树)的后代试验为研究材料。表型测量和估计的遗传参数(家族遗传力，现实增益和遗传增益)在9岁、15岁和18岁时进行，分别。遗传评估得出以下结果：（1）株高（PH）的家族内方差分量大于家族间的方差分量，而其他性状的家族间方差成分(胸高直径(DBH)，冠部直径(CD),分支下的高度（HUB），茎平直度(DS))大于家族内部，表明家庭之间存在丰富的差异和选择的潜力。（2）在半轮换期（18岁），性状间存在显著的相关性。树干扭曲（1-3级直线度）的树木比例达到48％。DS显著影响生长性状，其中PH和DBH受影响最大。扭曲树干造成的体积损失率为18.06-56.75%，这意味着在人工选择后无法完全消除躯干扭曲。(3)树形的影响,表冠宽度,后备箱音量增加，和PH之间的早晚相关性，DBH和体积极显著。表型变异系数的范围，生长性状的遗传变异系数和家族遗传力(PH，DBH,和体积）为44.29-127.13%，22.88-60.87%，和0.79-0.83。(4)采用隶属度函数结合独立选择的方法,共筛选出21个优良家庭。与中期选拔（18岁）相比，早期选择(9岁)的准确率达到77.5%。所选家庭的遗传增益和现实增益范围分别为5.79-19.82％和7.12-24.27％，分别。本研究可为针叶树种的选育提供一些有益的参考。
