不同种源香椿无性系苗期表型性状变异及其与地理-气候因子的相关性

Phenotypic trait variations of Toona sinensis clones from different provenances at seedling stage and their correlations with geographical-climatic factors

以香椿〔Toona sinensis(A.Juss.)Roem.〕12个种源142个无性系为研究对象,研究了不同种源香椿无性系苗期的表型性状变异,探究其表型性状间及表型性状与地理-气候因子间的相关性。结果表明:香椿无性系苗期表型性状在种源间和种源内差异极显著(P<0.01),且种源内的变异大于种源间的变异。12个种源香椿无性系苗期表型性状的平均变异系数变幅为18.17%~26.34%,变异系数较大。聚类分析结果表明:在欧氏距离17处,供试的12个香椿种源被分成3类,3个类群之间具有明显的表型分化,但聚类结果与地理分布无明显相关性。相关性分析结果表明:香椿无性系苗期的树皮颜色与苗高、地径分别呈显著(P<0.05)和极显著负相关,与叶痕长和叶痕宽的相关性不显著;苗高与经度呈显著负相关,与海拔呈显著正相关;地径与平均气温日较差呈显著负相关,与等温性呈极显著负相关。综上所述,不同种源香椿无性系苗期表型性状变异丰富,表型性状变异主要来源于种源内,具有优良种质资源的选择潜力,且在所收集的种源范围内,苗高的地理变异模式以经度和海拔变异为主。

Taking 142 clones from 12 provenances of Toona sinensis(A.Juss.)Roem.as research objects,the phenotypic trait variations of T.sinensis clones from different provenances at seedling stage were investigated,and the correlations between their phenotypic traits and between phenotypic traits and geographical-climatic factors were explored.The results show that there are extremely significant differences(P<0.01)in phenotypic traits of T.sinensis clones at seedling stage both among provenances and within provenance,and the variation within provenance is greater than that among provenances.The range of average coefficients of variation of phenotypic traits of T.sinensis clones from 12 provenances at seedling stage is 18.17%-26.34%,and the coefficients of variation are relatively large.The cluster analysis result shows that at the Euclidean distance of 17,12 test provenances of T.sinensis are divided into three groups,and there are evident phenotypic differentiations among the three groups,but there is no obvious correlation between the clustering results and the geographical distribution.The correlation analysis result shows that bark color of T.sinensis clones at seedling stage shows significant(P<0.05)and extremely significant negative correlations with seedling height and ground diameter,respectively,but has no significant correlations with leaf scar length and leaf scar width;seedling height shows a significant negative correlation with longitude,and a significant positive correlation with elevation;ground diameter shows a significant negative correlation with mean temperature diurnal range,and an extremely significant negative correlation with isothermality.In conclusion,the phenotypic trait variations of T.sinensis clones from different provenances at seedling stage are rich and mainly originate within provenance,which indicates the potential for selection of superior germplasm resources.Within the range of provenances collected,the geographical variation pattern of seedling height is dominated by variations in longitude and elevation.