毛白杨抗寒无性系选育

Selective Breeding of Clone Resistant to Cold on Populus tomentosa

利用全国毛白杨优树基因资源进行抗寒无性系选育，国内尚属首次。经８年系统研究，选育出１７个抗寒无性系，其中Ｌｘ、１１７１等７个无性系的材积超过小黑杨２３％以上，病虫害少，树干通直，无冻害。苗期复测和区域中试表明，这些抗寒无性系在北纬４０°左右，年均气温６℃以上，年平均极端最低温－２７．８℃和极值－３２．４℃的生态条件下，能正常发育生长并保持毛白杨特有的速生性，适宜在北方平川寒冷地区推广。而目前推广的三倍体毛白杨抗寒性差，冻害严重，只宜在热量条件较好的晋南推广。

It is first time in China to make selective breeding of clone resistant to cold using gene resouce of selected Populus tomentosa plant.Through 8 years systemetical research,17 varieties of the clone were selec ted,wood volume of 7 varieties of which have passed that of little black poplar over 23 percent.There are little injury by disease and insect,no freezing stage and compartmentation show that under such bioecological conditions as 40 degrees north latitude,over 6 celsius degree annual mean atmospheric temperature,-27 8 celsius degree annual mean extreme lowest temperature and -32 4celsius degree the minimum of the temperature,these varieties of the clone resistant to cold can grow and develop,and maintainthe specific fast growing caperbility of Populus tomentosa,suitable to popularization in cold area of northern flat,but present spreaded triploid Populus tomentosa,becauce of the lower cold resistance,is only limited to the south of Shanxi province.