Production of some clonally seeds were low, these lines were easy to be lost while planting.

由于部分无性系种子产量低，育苗、这些家系容易丢失。

In this study, 21 elite poplar varieties of Tacamahaca and Aigeiros were fingerprinted using AFLP markers.

本试验采用AFLP对来自青杨和黑杨的21个重要杨树品种（无性系）的鉴定与遗传相关性进行。

The content of flavanone and lactone in leaf and the leaf output were studied by randomizing block arrangement of 31 gingko female varieties (strain) and 4 staminiferous plant type single clone.

摘要采用31个银杏雌性品种和4个雄株类型的单株无性系，随机区排列，对叶产量性状及其与叶产量的相关性，叶黄酮、内酯含量进行。