Moon H S, Nicholson J S, Lewis R S
Campus Box 7620, Crop Science Department, North Carolina State University, Raleigh, NC 27695, USA.
Genome. 2008 Aug;51(8):547-59. doi: 10.1139/G08-039.
The recent development of microsatellite markers for tobacco, Nicotiana tabacum L., may be valuable for genetic studies within the genus Nicotiana. The first objective was to evaluate transferability of 100 N. tabacum microsatellite primer combinations to 5 diploid species closely related to tobacco. The number of primer combinations that amplified scorable bands in these species ranged from 42 to 56. Additional objectives were to assess levels of genetic diversity amongst available accessions of diploid relatives closely related to tobacco (species of sections Sylvestres and Tomentosae), and to evaluate the efficacy of microsatellite markers for establishing species relationships in comparison with existing phylogenetic reconstructions. A subset of 46 primer combinations was therefore used to genotype 3 synthetic tobaccos and an expanded collection of 51 Nicotiana accessions representing 15 species. The average genetic similarity for 7 diverse accessions of tobacco was greater than the average similarity for N. otophora accessions, but lower than the average genetic similarities for N. sylvestris, N. tomentosa, N. kawakamii, and N. tomentosiformis accessions. A microsatellite-based phylogenetic tree was largely congruent with taxonomic representations based on morphological, cytological, and molecular observations. Results will be useful for selection of parents for creation of diploid mapping populations and for germplasm introgression activities.
烟草（Nicotiana tabacum L.）微卫星标记的最新进展可能对烟草属内的遗传研究具有重要价值。第一个目标是评估100对烟草微卫星引物组合对与烟草密切相关的5个二倍体物种的可转移性。在这些物种中能扩增出可计分条带的引物组合数量在42到56之间。其他目标包括评估与烟草密切相关的二倍体近缘种（森林烟草组和绒毛烟草组的物种）现有种质资源中的遗传多样性水平，以及与现有的系统发育重建相比，评估微卫星标记在建立物种关系方面的有效性。因此，使用46对引物组合的一个子集对3个人工合成烟草以及代表15个物种的51份烟草种质资源的扩展样本进行基因分型。7份不同烟草种质资源的平均遗传相似性大于耳状烟草种质资源的平均相似性，但低于林烟草、绒毛烟草、川上烟草和绒毛状烟草种质资源的平均遗传相似性。基于微卫星的系统发育树在很大程度上与基于形态学、细胞学和分子观察的分类学表述一致。研究结果将有助于为创建二倍体作图群体选择亲本以及种质渐渗活动。
