一.引言在我國北方楊樹是生長迅速的樹种,是城鄉居民日常需要的用材樹种之一,因为它生長迅速,因此也就成为綠化中的一个重要樹种,尤其是在華北及西北更是如此。在我國造紙工業及輕工業中楊樹亦是重要原料之一。楊樹在中國約有80种,分布很廣,但只应用这些种亦不能滿足我們的要求,因而用米丘林选种方法來创造新的优良的適合我們需要的、生長更速的品种巳成为迫切而必要的工作了。 I. Introduction Poplars in northern China are rapidly growing species and one of the timber species commonly used by urban and rural residents because of their rapid growth and therefore they have become an important tree species in greening especially in North China and Northwest China Even more so. Poplar is also one of the important raw materials in China’s paper industry and light industry. About 80 poplar species are widely distributed in China, but the application of these species alone can not meet our requirements. Therefore, the use of Michurin seed selection method to create new and better-suited to our needs, faster-growing varieties have Become urgent and necessary work.