楸树苗期优良家系及单株的配合选择

以河南南阳地区楸树优树子代为研究对象,分析苗期苗高、地径、单叶面积等6个性状。结果表明:家系间苗高、地径、叶长、叶宽、单叶面积和叶片数差异极显著,说明楸树半同胞家系间存在较大的变异,具有较大的选育潜力。各性状遗传力差异较大,但都属于中度以上遗传控制,苗高和地径的遗传力分别为0.581和0.663,单叶面积、叶片数的遗传力为0.683和0.874。以综合育种值为标准,选出9个苗期优良家系,苗高和地径的遗传增益分别达到6.32%和11.38%。从入选的9个优良家系内选择36株优良单株,其树高平均增加25.87%,遗传增益为15.03%,这些优良单株可作为营建楸树无性系试验林的材料。

Combined Selection of Excellent Families and Plus Trees of Catalpa bungei at Nursery Stage

The growing traits of Catalpa bungei seedlings were analyzed,including seedling height,ground diameter,leaf length,leaf width,leaf area and leaf number.The results showed that the differences of these growing characters were significant among families,indicating great potential for selection.Significant differences were found among the heritability of all characters,but the values of heritability of all traits were higher than 0.5.The values of heritability of height and ground diameter were 0.581 and 0.663,respectively,while the values of the heritability of leaf area and leaf number were 0.683 and 0.874.According to grading of breeding value,nine excellent families were selected.Expected genetic gains of height and ground diameter of the nine excellent families increased by 6.32% and 11.38%,respectively.Thirty-six plus tree were further selected form the excellent families.The tree height of the plus trees increased by 25.87% and their genetic gain were 15.03%.The plus trees can be used as standby materials in the establishment of excellent clone stands.