对I69〔Populus deltoids Bartr. cv. Lux〕、I72杨〔P.×euramericana (Dode) Guiniercv. SanMartino〕、NL 80351〔I 69×I 63(P. deltoidsBartr. cv. Harvard)〕、南林 95、南林 1388、南林 895、南林 447等7个杨树无性系的木材基本密度和纤维素含量进行了系统研究。其中,南林 95、南林 1388、南林 895、南林 447是从I 69×I 45〔P.×euramericana (Dode) Guiniercv.I 45/51〕杂交F1代中选育出来的新无性系。研究结果表明,同为11a生时,7个无性系胸径处木材基本密度差异达显著水平,从大至小依次为南林 895、I 72、I 69、南林 1388、南林 95、NL 80351、南林 447;不同杨树无性系间胸径处纤维素含量也存在显著差异,从高至低依次排序为南林 95、南林 447、南林 895、南林 1388、I 69、NL 80351、I 72。木材基本密度和纤维素含量在株内的径向变异规律均为从髓心向外以曲线形式缓慢增大, 其中后者的变异模式为以多项式方程来描述的效果最好。木材基本密度纵向变异规律为从树干基部向上有随树木高度的增加而逐渐增大的趋势,木材基本密度最小值出现在基径处。本文的研究结果可为杨树人工林的定向培育提供理论依据。

The wood basic density and cellulose content of 7 poplar clones were measured and the variation in wood basic density and cellulose content among clones and within trees were also analyzed. The 7 poplarclones were clone I-69 (Populus deltoids Bartr. cv. Lux), clone I-72〔 P.× euramericana(Dode)Guinier cv. San Martino〕, clone NL-80351, a hybrid of clone I-69 × clone I-63(P. deltoids Bartr. cv. Havard), and Nanlin-95,Nanlin-895,Nanlin-447 andNanlin-1388,the four clones from new hybrids of clone I-69× cloneI-45〔 P.× euramericana(Dode)Guinier cv. I-45/51〕. The results indicated that there were significant differences both in wood basic density and cellulose content among 7 poplar clones. The order of mean wood basic density at breast height from high to low was Nanlin-895, I-72, I-69, Nanlin-1388, Nanlin-95, NL-80351,Nanlin-447 in 11 years old, while the order of mean cellulose content at breast height from high to low was Nanlin-95, Nanlin-447, Nanlin-895, Nanlin-1388, I-69, NL-80351, I-72. Wood basic density and cellulose content gradually increased from pith to bark. Regression analysis indicated that a polynomial function best described the relationship both between cellulose content and growth ring number(cambial age). Wood basic density was the least at the base of trees and gradually increased from base to peak. The results from this study would provide some bases for oriented culture of poplar plantations in the future.