银中杨抗病虫性研究

用室内外接种及自然感病的方法，对银中杨抗烂皮病进行测定，采用系统聚类方法进行分析，结果证明银中杨为感病最轻品种，聚在第一类，并对鉴定林中　１６个品系的病情指数作方差分析，结果表明各品系间感病指数有极度显著差异。同时对银中杨及对照品种的虫害按五级分类标准进行调查并计算受害指数，结果表明银中杨是抗杨干象、白杨透翅蛾等虫害的优良树种。

Study on resistances to disease and insect pest of Populus alba×Populus berolinensis

By inoculating in and out of door and infecting natural ly,resistance to Valsa sordida Nits of the poplar was determined,a nd analysed using system cluster method.Results have proved the plant to be the most slightly affected.Variance analysis was conducted for disease indexes of 16 strains.Results showed there are extveme significant differences between all th e strains.Insect pests of P.alba×berolinensis and the check was i nvestigated by five classification standards and the danage index was calculated .The result indicated that the plant is the superior variety in resistances to Cryptorrhynchus lapathi linnaeus and Parathrene tabaniformi s Rottenberg.