不同产地木荷优树无性系表型多样性

利用来自17个产地的170个木荷优树无性系,分析表型性状在产地间和产地内的变异和性状间及性状与地理气候因子的相关性,基于13个性状对参试无性系产地进行主成分和聚类分析。结果显示:木荷优树无性系表型性状在产地间和产地内均呈极显著差异,枝下高变异最大26.6%,叶平均宽变异最小10.17%,说明木荷优树无性系生长、形质和叶片性状变异丰富,具有较好的改良基础。表型分化系数平均为43.24%,处于中等分化水平,产地内变异(31.42%)大于产地间变异(25.05%),生长性状变异是表型多样性的主要因素。性状相关分析表明,高径生长量较大的优树无性系其树干通直、枝下高大且分枝较粗,而与最大分枝角相互独立,叶片大和叶形宽圆的无性系可能生长更快。各性状与地理气候因子间的相关性表明,生长性状呈纬向变异,南部地区速生性较强;形质性状和叶片性状为呈经向变异,东部地区树干通直度相对较低,最大分枝角较大,叶片短小且宽圆。通过主成分分析认为,枝下高、冠幅是生长性状中的主要区别性状,而叶面积和叶宽长比是叶片性状的主要区别性状。基于聚类分析将参试的17个木荷优树无性系产地归为4个类型,其中类型Ⅰ和类型Ⅳ的无性系主要分别来自中部种源区和北部种源区,生长相对缓慢,而类型Ⅱ和类型Ⅲ的无性系主要来自中心种源区和中部种源区,速生性较强。

Phenotypic Diversity Analysis of Schima superba Superior Clones from Different Locations

With 170 Schima superba superior clones from 17 locations, we analyzed the variation of phenotypic traits among and within locations and the correlation among traitsas well as between traits and geographical and climatic factors. Principal component and clustering analysis were carried out on the tested clones with 13 traits. Thephenotypic traits of S. superba superior clones showed significant differences among and within the locations, the variation of clear bole height was the largest(26.6%) and the variation of leaf average width was the smallest(10.17%), the growth trait and leaf morphological variation of S. superba superior clones were abundant and had good basis for improvement. The average coefficient of phenotypic differentiationtraits was 43.24%, at a moderate level of differentiation, and the differences within the locations were greater(31.42%) than those among the locations(25.05%), the variation of growth trait were the main factor of phenotypic diversity. Trait correlation analysis showed that superior clones with large growth in height and diameter may grow faster with straight trunk, tall clear bole height and thick branches diameter, and were independent of the maxi-branch angle, and the clones with large and wide round leaves may grow faster. The correlation between traits and the geographical and climatic factors showed that the growth traits were latitude variation and the growth was relatively faster in the southern region, the trunk shape traits and leaf traits were longitude variation, the trunk straightness was relatively low, the maximum branch angle was large, and the leaves were short and wide round in the eastern region. Principal component analysis indicated that the clear bole height and the crown width were the main distinguishing traits in the growth traits, the leaf area and leaf width-length ratio were the main distinguishing traits of the leaf morphology. By cluster analysis, 17 locations of S. superba superior clones were divided into four types, among them, the clones of type I and type IV were mainly from the middle provenance and northern provenance area, and the growth was relatively slow, and the clones of type II and type III mainly came from the central provenance and the middle provenance, and the growth was relatively faster.