黑杨树冠雌花分布与少絮无性系的选择

以美洲黑杨种内杂交得到的29个后代雌株为材料,对杨絮的空间分布、杨絮量、结实量、生长量等相关的10个数量性状进行调查分析,研究了杨絮的影响因素,并筛选杨树少絮优良无性系。结果表明:杨絮主要集中于树冠的集花区,花枝数、果序数、杨絮量及种子量在冠层中的分布均表现为中部上部下部。单株杨絮量与单株花枝数及平均冠幅呈极显著相关,与平均胸径、集花区长、单果序种子数、单株果序数、单株种子数呈显著相关;与树高及枝下高不相关。遗传变异分析表明:各性状在杂交子代中均达到极显著差异且大都属于高水平重复力,且差异主要受遗传因素控制。从调查的8个相关性状中选出可代表杨絮量、集花区、单果序结实量等相关指标的3个主成分,代表了8个调查性状信息总量的75.487%。最后,依据主成分得分及相关性状综合评选出了92、121和260三个少絮无性系。

Distribution Pattern of Female Flowers in Crown and Less Catkins Clones Selection of Aigeiros

To determine the factors influencing the spatial distribution of poplar catkins, and to screen poplar clones for fewer catkins, 10 quantitative traits related to the quantity of poplar catkins, seed yields and growth increments were measured on 29 female plant clones in the F₂ generation of an intraspecific cross of Populus deltoides. The results indicated that the poplar catkins were mainly distributed in tree crowns, with the amount of flowering branches, infructescences, poplar catkins and seed yields being the highest in the middle layer of the crown, the lowest in the lowest layer and intermediate in the highest layer of the crown. The quantity of poplar catkins produced by an individual plant was significantly positively correlated with the mean crown range, and the amount of flowering branchs of individual plant,additionally, was significantly positive correlation with the diameter at breast height (DBH), the length of catkin concentration, the seed amount of each infructescence, the infructescence amount of each plant, and the seed amount of each plant,but was not correlated with tree height and height under branches. These traits varied significantly among hybrid progeny showing high repeatability, indicating that the trait variation was controlled by genetic factors. Three principal components, representing the quantity of catkins, the catkin concentration, the seed yields of each infructescence and other related indicators, were extracted from the 8 correlation characters investigated, and in combination represented 75.487% of total information for the 8 characters. Based on ranking of principal component scores and related traits, all the traits were comprehensively evaluated and 92 121 and 260 three clones with fewer catkins were obtained.