桑天牛对白杨派无性系危害程度的研究

Study on Apriona germari Damaging the Clones of Sect.Leuce

毛白杨（ＰｏｐｕｌｕｓｔｏｍｅｎｔｏｓａＣａｒｒ．）是中国固有的乡土树种，以山东、河南、河北三省及安徽、江苏北部及陕西关中一带分布较为集中［１，２］。毛白杨生长快，树干高耸挺拔，木材质轻色白、结构细密、纹理通直，是优良的建筑、造船、造纸、胶合板、火柴...

The paper discusses an investigation on damage degree of 34 clones of sect. leuce of five year plantation caused by Apriona germari . Four statistical variables were selected,i.e.insect density (head/tree),insect tree percentage (%),infection index and borer damage duration (year). Use the method of vague cluster analysis——making analysis by taking Euclidean Distance as Group Average Method of cluster statistical variable. The conclusion shows that the damage degree of 34 clones by A.germari has remarkable difference,or different clone has showen obvious different resistance to A.germari . According to Cluster Redigree Figure,the 34 clones can be divided into four typers. T 23 ,T 12 ,T 32 and other nine clones as fourth type,insect tree percentage 7%～25%,infection index 11.1～29.5,insect density<1.0 head/tree which called resistance clones to infectation.