改良杨树品种之间的耐寒性差异要点:为了明确各品种之间耐寒性的差异以及耐寒性增大过程和成熟过程的关系,于1964年9月到1966年2月,采用16个改良杨树品种的当年插条苗,就其耐寒性增大随季节的变化,苗木生长的停止期,苗木的木质化,形成层活动停止期,在各组织淀粉的储藏与减少,休眠期与打破休眠期等问题进行了研究。 In order to clarify the difference of cold tolerance among varieties and the relationship between the process of increasing cold tolerance and maturation, from September 1964 to February 1966, 16 improved poplars In the same year, cuttings of tree species were changed with the increase of cold tolerance, the growth of seedlings stopped, the lignification of seedlings, the stop of formation activity, the storage and reduction of starch in various tissues, the dormancy period and the break of dormancy Period and other issues were studied.