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、造林时这些家系容易丢失。

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21重要杨树品种（无性系）鉴定与传相关性进行了研究。

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雌性品种和4雄株类型单株无性系，随机区排列，对叶产量性状及其与叶产量相关性，叶黄酮、内酯含量进行了研究。