Keim P, Paige K N, Whitham T G, Lark K G
Department of Biology, University of Utah, Salt Lake City 84112.
Genetics. 1989 Nov;123(3):557-65. doi: 10.1093/genetics/123.3.557.
Restriction fragment length polymorphisms were used to distinguish genotypes of two species of Populus, P. fremontii ('Fremont') and P. angustifolia ('narrowleaf'). Both inter- and intraspecific polymorphisms were detected in these cottonwood trees. The interspecific variation was much greater than the intraspecific variation. This permitted identification of parental genotypes within individual trees of a hybrid swarm which exists in an overlap zone between the two species. Within this hybrid swarm, individual trees are either F1 hybrids or backcrosses with a pure 'narrowleaf' parent; no progeny were found that could be attributed to crossing between F1 hybrid trees, or to backcrossing between F1 hybrid trees and 'Fremont'.
限制性片段长度多态性被用于区分两种杨树的基因型，即弗里蒙特杨（‘Fremont’）和窄叶杨（‘narrowleaf’）。在这些三角叶杨中检测到了种间和种内多态性。种间变异远大于种内变异。这使得能够在两种杨树重叠区域存在的杂交群体的单株树木中鉴定亲本基因型。在这个杂交群体中，单株树木要么是F1杂种，要么是与纯‘窄叶’亲本的回交后代；未发现可归因于F1杂种树木之间杂交或F1杂种树木与‘弗里蒙特’杨之间回交的后代。
