【摘要】 [目的]为筛选优质桑树种质和深入开发其利用价值提供依据。[方法]在实地调查西藏野生桑树资源的基础上,应用主成分分析法对4个野生桑树种(变种)的16个数量性状特征进行统计分析。[结果]在第一主成分中,胸径的权重正值最大,是对第一主成分影响最大的特征向量;在第二主成分中,叶裂宽的特征负荷值较大、叶柄与着生枝夹角和叶形指数的权重正值较大;在第三主成分中,一年生枝的叶数、枝长、枝粗和冠幅发达程度的权重正值较大。山桑树体高大且通直,可用于绿化河堤和建设农田防护林,还可用作培育叶用桑树的优良亲本;鸡桑具有很好的观赏价值。一些蒙桑的果实大而鲜艳,味道甜美,可被开发成食品。[结论]该研究对开发西藏野生桑树资源,促进西藏经济发展意义重大。更多还原

【Abstract】 [Objective] The purpose was to supply basis for screening high-quality mulberry germplasm and developing its utilization value thoroughly.[Method] Based on the field investigation on the wild mulberry resources in Tibet,the 16 quantitative characters of 4 wild mulberry variants were statistically analyzed by principal component analysis.[Result] Among the 1st principal components,the positive weight value of chest diameter was greatest and it was the eigenvector with greatest influence on the 1st principal components.Among the 2nd principal components,the character loading value of leaf-lobed width and the positive weight values of angle between leafstalk and its branch and leaf-shape index were greater.Among the 3rd principal components,the positive weight values of leaf number,branch length,branch thickness and developed degree of crown size of 1 year old branches were greater.The tree body of mountain mulberry was high,large and straight.It could be used in greening riverbanks and constructing farmland shelterbelt and it also could be used as good parent in breeding leaf-use mulberry.The Japanese mulberry had very high ornamental value.Some Mongolian mulberries had big fruits with bright color and mellifluence tastiness and these fruits could be developed as food.[Conclusion] The research had important meaning for developing the wild mulberry resources and promoting the economic development in Tibet.更多还原