<正>利用随机多态扩增DNA（RAPD）分子标记对53个墨西哥落羽杉无性系的研究表明：31个随机引物共扩增出了2111条谱带，其中118餐谱带在无性系间呈现多态性。多态位点占48.96%；用POPGENE软件对无性系进行遗传分析。得出无性系问的遗传距离为0.27l～0.537，说明无性系间的遗传差异相对较大。通过聚类分忻将53个优良无性系分为两大类，同时利用RAPD分子标记构建了53个无性系的指纹图谱，可对墨西哥落羽杉优良无性系进行区分和鉴定。

100kg seeds of Taxodium mucronatum Ten. of eastern Mexico were introduced to Wujiang City Nursery Co., Ltd in 2000, and a population of 100000 seedlings was established next year. In 2003,983 plus trees were selected from it based on the individual investigation of growth and crown characteristics, among which, 837 plus trees were selected for their merit of fast growing, 78 trees for their unique crown, and 48 for their golden leaves. The selection differential (S) of basal diameter (D) and height (H) were 0.84 cm and 56.78cm respectively, the selection intensity (I) of D and H were 1.5 and 1.89 respectively. On the whole, a conclusion could be drawn that vegetative propagation could be easily realized due to their high survival percentage (86% for cuttings and 95% for transplants), whereas a significant variation of survival ratio among clones was found.