本文简要介绍了90年代以来利用RFLP和RAPD分子标记构建林木的遗传连锁图谱，并应用高密度的遗传连锁图谱上的分子标记进行林木重要数量性状的QTL作图，进而阐明控制多基因的数目，确定QTL在染色体上的位置，测定单个基因的作用效应。遗传连锁图谱构建和数量性状基因定位预示林木遗传育种研究将产生深刻的变革。

本文利用RAPD标记和美洲黑杨（Populus deltoides）×欧美杨（P. euramericana）的F1群体，构建了美洲黑杨×欧美杨的分子标记连锁图谱。实验过程中对1040个寡核苷酸随机引物进行了重复筛选，共选出127个引物用于作图群体（包括双亲共92个无性系）的随机扩增，这127个引物产生229个多态基因座，其中符合“拟测交”1:1分离的有214个。利用多点连锁分析，形成19个连锁群及6个三连体和14个连锁对。由19个连锁群构成的图谱含标记129个，总图距为191412cM，覆盖杨树基因组约73162%。标记间的平均间距为14184cM。本研究获得了中等密度的美洲黑杨×欧美杨的一个连锁框架。

根据20个不同RAPD随机引物对杨树DNA的扩增结果，对四甲基氯化铵（TMACI）在杨树RAPD扩增反应中的作用进行了研究，发现TMACI可明显改善杨树的RAPD扩增效果，因此TMACI可作为一种有效成分加入杨树RAPD反应体系中。同时比较了不同浓度的TMACI对杨树RAPD扩增反应的影响，确定最适合杨树RAPD扩增反应的TMACI浓度为10～50μmolPL。利用3个具亲缘关系的杨树家系对含TMACI的RAPD反应体系的实验结果进行验证，证实该体系获得的遗传信息是可靠的。

利用300个随机的寡核苷酸引物和马尾松（Pinus massoniana Lamb.）种子的胚乳（大配子体）产生的随机扩增多态性DNA（RAPD）分子标记，进行马尾松标记连锁图谱的构建。经筛选共获得64个稳定的RAPD标记，利用多点连锁分析，其中的48个标记分属于13个不同的连锁群（连锁对），该图谱覆盖的基因组总长度约为692.5cM（centimorgan），标记问平均距离约为14.7cM，它为马尾松连锁图谱的构建提供了一个连锁框架。

We reported our preliminary study on mapping of the expressed sequence tag (EST) using single- stranded DNA conformation polymorphism (SSCP) on polymerase chain reaction (PCR) product. Five ESTs primer pairs, developed from nuclear genes including CAD(cinnamyl-alcohol dehydrgenase), CHS(chalcone synthase), NIR (nitrite reductase), ARA554 (cDNA expressed in differentiating xylem in Pinus taedae) and GS (glutamine synthetase), were selected to optimize the experimental protocol and generate mapping markers in the megagemtophytes from a single tree of Pinus massoniana. Our ultimate goal was to use SSCP approach to construct a transcriptional map for comparative mapping studies in P. massoniana. The efficiency to construct a transcriptional map in P. massoniana based on the published EST primer pairs derived from other pine species critically depended on the successful amplification of ESTfragments and the ratio of the heterozygous loci revealed in P. massoniana. In this study, 3 (60%) out of 5 tested EST primer pairs were succeeded in amplification, however, only 1 (20%) gene was heterozygous in the tested tree. The ratio of heterozygous loci detected in this study was similar to that revealed by anonymous marker in P. taeda. Therefore, a low efficiency would be expected if the map would be constructed using single pedigree. The segregation ratio of loci revealed by primer pairs would be higher if multiple pedigrees would be used. We proposed that consensus mapping approach based on multiple-pedigree should be used for EST mapping and therefore to increase the efficiency of EST mapping.