‘美洲黑杨’不同家系苗期生长特征比较

为获得适合长江中下游江汉平原发展的杨树新品种，以优良美洲黑杨无性系为亲本，配制了4个杂交组合，对获得的子代群体无性系化后进行生长性状调查，比较不同家系生长特征和生长节律变化。结果表明：ZS8×2-7的苗高和地径均服从正态分布(P=0.200>0.050)，2-2×2-46的地径服从正态分布(P=0.057>0.050)，其余家系的生长性状偏度值在-0.482~0.304之间，峰度值大多在-0.363~0.155之间，接近正态分布，4个家系苗高分布呈左偏态，大于均值的株数较多，地径分布呈右偏态，小于均值的株数相对较多；2个生长性状在家系间均存在显著差异(P<0.05)，但优势并不明显，苗高均值最大的2-2×2-38比均值最小的ZS8×2-7仅高7.14%，地径均值最大的2-2×2-9比均值最小的ZS8×2-7仅粗7.52%；4个家系从6月到10月的生长节律相近，其中在7月初到7月中旬之间可能出现了夏季休眠。基于各家系生长性状的分布情况，均可开展一定强度的早期选择和淘汰以选择优良无性系。

Comparative Study on the Growth Characteristics in Different Pedigrees Seedlings of Populus deltoides

In order to obtain new varieties which were suitable for the Yangtze River Basin, 4 combinations of Populus deltoides were selected for hybridization. Growth characteristics were investigated which were from the clones of the offspring, to compare the differences of the growth characteristics and growth rhythm in 4 combinations of Populus deltoids. The result of the statistics and analysis showed that: the height and diameter were normal distribution in ZS8×2-7 (P=0.200>0.050), the diameter was normal distribution in 2-2×2-46 (P=0.057>0.050). The skewness value of growth characteristics was between -0.482 to 0.304 and the kurtosis value was mostly between -0.363 to 0.155 in the rest of the pedigrees, close to a normal distribution. The distribution of the height was left skewness distribution, it meant that the number of trees which were greater than the average was more, in contrast, the diameter was right skewness distribution, the number of trees which were greater than the average was less. There were significant differences in height and ground diameter among the pedigrees (P<0.05), but it was not obvious, the average height of 2-2×2-38 was the largest and the smallest one was ZS8×2-7, it was only 7.14% higher. The average diameter of 2-2×2-9 was the largest and the smallest one was ZS8×2-7, it was only 7.52% larger. The growth rhythm of those pedigrees was similar from June to October, it appeared summer dormancy between early July to mid-July possibly. According to the distribution of growth characteristics in those pedigrees, it could carry out the elimination and early selection of superior clones.