对５５号杨等８个黑杨派无性系生根性状的遗传变异的研究表明，美洲黑杨和欧美杨无性系在最早生根时间、先期根数和诱导根数等方面均存在显著差异。生根对的广义遗传力对水培后期变化不大，表明生根力对环境条件是不敏感的；而最早生根时间的广义遗传力较大，说明各无性系开始生根的时间是受遗传基因控制的。 The study on the genetic variation of root traits of eight Populus climber clones in 55 poplars showed that there were significant differences in the earliest rooting time, initial root number and induced root number between American poplar and European poplar clones. The root heritability of general heritability did not change much in the late stage of hydroponics, indicating that the rooting force was not sensitive to environmental conditions; while the broad heritability of the earliest rooting time was larger, indicating that the rooting time of each clonal root was controlled by the genetic gene .