Rahman M H, Dayanandan S, Rajora O P
Department of Renewable Resources, Faculty of Agriculture, Forestry and Home Economics, University of Alberta, Edmonton, Canada.
Genome. 2000 Apr;43(2):293-7.
Markers for eight new microsatellite DNA or simple sequence repeat (SSR) loci were developed and characterized in trembling aspen (Populus tremuloides) from a partial genomic library. Informativeness of these microsatellite DNA markers was examined by determining polymorphisms in 38 P. tremuloides individuals. Inheritance of selected markers was tested in progenies of controlled crosses. Six characterized SSR loci were of dinucleotide repeats (two perfect and four imperfect), and one each of trinucleotide and tetranucleotide repeats. The monomorphic SSR locus (PTR15) was of a compound imperfect dinucleotide repeat. The primers of one highly polymorphic SSR locus (PTR7) amplified two loci, and alleles could not be assigned to a specific locus. At the other six polymorphic loci, 25 alleles were detected in 38 P. tremuloides individuals; the number of alleles ranged from 2 to 7, with an average of 4.2 alleles per locus, and the observed heterozygosity ranged from 0.05 to 0.61, with an average of 0.36 per locus. The two perfect dinucleotide and one trinucleotide microsatellite DNA loci were the most informative. Microsatellite DNA variants of four SSR loci characterized previously followed a single-locus Mendelian inheritance pattern, whereas those of PTR7 from the present study showed a two-locus Mendelian inheritance pattern in controlled crosses. The microsatellite DNA markers developed and reported here could be used for assisting various genetic, breeding, biotechnology, genome mapping, conservation, and sustainable forest management programs in poplars.
从部分基因组文库中开发并鉴定了8个新的微卫星DNA或简单序列重复（SSR）位点的标记，用于颤杨（Populus tremuloides）。通过测定38个颤杨个体的多态性，检验了这些微卫星DNA标记的信息含量。在控制杂交后代中测试了所选标记的遗传情况。6个已鉴定的SSR位点为二核苷酸重复（2个完美型和4个非完美型），三核苷酸和四核苷酸重复各1个。单态SSR位点（PTR15）为复合非完美二核苷酸重复。一个高度多态性SSR位点（PTR7）的引物扩增出两个位点，等位基因无法分配到特定位点。在其他6个多态性位点，38个颤杨个体中共检测到25个等位基因；等位基因数量从2到7不等，每个位点平均有4.2个等位基因，观察到的杂合度从0.05到0.61不等，每个位点平均为0.36。两个完美二核苷酸和一个三核苷酸微卫星DNA位点信息含量最高。先前鉴定的4个SSR位点的微卫星DNA变异遵循单基因孟德尔遗传模式，而本研究中的PTR7在控制杂交中表现出双基因孟德尔遗传模式。本文开发并报道的微卫星DNA标记可用于辅助杨树的各种遗传、育种、生物技术、基因组作图、保护和可持续森林管理项目。
