引言赤栎产于北美,分布范围从北大西洋海岸到中西大草原,并越过圣劳伦斯河一直到接近墨西哥湾海岸(图1)。赤栎曾分为2个亚种,北方赤栎(Qucrcus berealis)和东方赤栎(Q.borealis var.maxima)。但因为基因渗入和生育纯种的衰败,这2个类型已经不再被认为是分别的分类单位了(Little 1953)。因为赤栎到达生殖成熟期所需时间较长并且营养繁殖困难,所以对它的遗传研究进行得很少。对赤栎的早先研究表明,它的遗传变异总的讲来是不连续的(DeneKe 1975;Gall Introduction Red oak is produced in North America and extends from the North Atlantic coast to the mid-west prairie and across the St. Lawrence River to the Gulf Coast (Figure 1). Red oak has been divided into two subspecies, the northern red oak (Qucrcus berealis) and the East Red Oak (Q.borealis var.maxima). However, these two types are no longer considered as taxonomic units due to the decline of introgression and birth purebred (Little 1953). Because of the long time it takes for red oaks to reach the reproductive maturity stage and the difficulties of vegetative propagation, so little has been done on their genetic studies. Earlier studies of red oak showed that its genetic variation was in general discontinuous (Dene 1975; Gall