State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin, China.
Jilin Provincial Academy of Forestry Sciences, Changchun, China.
PLoS One. 2024 Mar 7;19(3):e0298918. doi: 10.1371/journal.pone.0298918. eCollection 2024.
This study, conducted in China in November 2020, was aimed at exploring the variations in growth traits among different provenances and families as well as to select elite materials of Juglans mandshurica. Thus, seeds of 44 families from six J. mandshurica provenances in Heilongjiang and Jilin provinces were sown in the nursery and then transplanted out in the field. At the age of 5 years, seven growth traits were assessed, and a comprehensive analysis was conducted as well as selection of provenance and families. Analysis of variance revealed statistically significant (P < 0.01) differences in seven growth traits among different provenances and families, thereby justifying the pursuit of further breeding endeavors. The genetic coefficient of variation (GCV) for all traits ranged from 5.44% (branch angle) to 21.95% (tree height) whereas the phenotypic coefficient of variation (PCV) ranged from 13.74% (tapering) to 38.50% (branch number per node), indicating considerable variability across the traits. Further, all the studied traits except stem straightness degree, branch angle and branch number per node, showed high heritability (Tree height, ground diameter, mean crown width and tapering, over 0.7±0.073), indicating that the variation in these traits is primarily driven by genetic factors. Correlation analysis revealed a strong positive correlation (r > 0.8) between tree height and ground diameter (r = 0.86), tree height and mean crown width (r = 0.82), and ground diameter and mean crown width (r = 0.83). This suggests that these relationships can be employed for more precise predictions of the growth and morphological characteristics of trees, as well as the selection of superior materials. There was a strong correlation between temperature factors and growth traits. Based on the comprehensive scores in this study, Sanchazi was selected as elite provenance. Using the top-percentile selection criteria, SC1, SC8, DJC15, and DQ18 were selected as elite families. These selected families exhibit genetic gains of over 10% in tree height, ground diameter and mean crown width, signifying their significant potential in forestry for enhancing timber production and reducing production cycles, thereby contributing to sustainable forest management. In this study, the growth traits of J. mandshurica were found to exhibit stable variation, and there were correlations between these traits. The selected elite provenance and families of J. mandshurica showed faster growth, which is advantageous for the subsequent breeding and promotion of improved J. mandshurica varieties.
本研究于 2020 年 11 月在中国进行，旨在探索不同种源和家系之间的生长性状差异，并筛选出核桃楸的优良材料。因此，在苗圃中播种了来自黑龙江和吉林省 6 个种源的 44 个家系的种子，然后在田间移栽。在 5 年生时，评估了 7 个生长性状，并进行了综合分析和种源与家系的选择。方差分析表明，不同种源和家系之间的 7 个生长性状存在显著差异（P<0.01），这证明了进一步进行选育工作的合理性。所有性状的遗传变异系数（GCV）范围为 5.44%（分枝角度）至 21.95%（树高），表型变异系数（PCV）范围为 13.74%（变细）至 38.50%（每个节点的分枝数），表明各性状存在较大的变异性。此外，除了树干直度、分枝角度和每个节点的分枝数外，所有研究的性状均表现出较高的遗传力（树高、地径、平均冠宽和变细，均高于 0.7±0.073），表明这些性状的变异主要由遗传因素驱动。相关性分析表明，树高与地径（r=0.86）、树高与平均冠宽（r=0.82）和地径与平均冠宽（r=0.83）之间存在很强的正相关。这表明这些关系可以用于更准确地预测树木的生长和形态特征，以及选择优良材料。温度因子与生长性状之间存在很强的相关性。根据本研究的综合得分，三岔子被选为优良种源。采用最优百分位选择标准，选择了 SC1、SC8、DJC15 和 DQ18 作为优良家系。这些选定的家系在树高、地径和平均冠宽方面的遗传增益超过 10%，表明它们在林业中具有显著的潜力，可以提高木材产量并缩短生产周期，从而有助于可持续森林管理。本研究发现，核桃楸的生长性状表现出稳定的变异，并且这些性状之间存在相关性。所选的优良种源和家系的核桃楸生长更快，这有利于后续的选育和推广改良的核桃楸品种。
