INRA, UMR118 APBV, BP35327, F-35653 Le Rheu cedex, France.
INRA Institut Jean-Pierre Bourgin, Station Génétique et d'Amélioration des Plantes, F-78026 Versailles, France.
New Phytol. 2011 Aug;191(3):884-894. doi: 10.1111/j.1469-8137.2011.03729.x. Epub 2011 Apr 21.
• Polyploids can be produced by the union of unreduced gametes or through somatic doubling of F(1) interspecific hybrids. The first route is suspected to produce allopolyploid species under natural conditions, whereas experimental data have only been thoroughly gathered for the latter. • We analyzed the meiotic behavior of an F(1) interspecific hybrid (by crossing Brassica oleracea and B.rapa, progenitors of B.napus) and the extent to which recombined homoeologous chromosomes were transmitted to its progeny. These results were then compared with results obtained for a plant generated by somatic doubling of this F₁ hybrid (CD.S₀) and an amphidiploid (UG.S₀) formed via a pathway involving unreduced gametes; we studied the impact of this method of polyploid formation on subsequent generations. • This study revealed that meiosis of the F₁ interspecific hybrid generated more gametes with recombined chromosomes than did meiosis of the plant produced by somatic doubling, although the size of these translocations was smaller. In the progeny of the UG.S₀ plant, there was an unexpected increase in the frequency at which the C1 chromosome was replaced by the A1 chromosome. • We conclude that polyploid formation pathways differ in their genetic outcome. Our study opens up perspectives for the understanding of polyploid origins.
• 多倍体可以通过未减数配子的融合或通过 F1 种间杂种的体细胞加倍产生。第一种途径被怀疑在自然条件下产生异源多倍体物种，而后者的实验数据仅被彻底收集。• 我们分析了一个 F1 种间杂种（通过杂交甘蓝和油菜，油菜的祖先）的减数分裂行为，以及重组同源染色体在多大程度上传递给其后代。然后将这些结果与通过体细胞加倍产生的这种 F1 杂种（CD.S0）和通过涉及未减数配子的途径形成的双二倍体（UG.S0）植物的结果进行比较；我们研究了这种多倍体形成方法对后代的影响。• 这项研究表明，F1 种间杂种的减数分裂产生了更多带有重组染色体的配子，而体细胞加倍产生的植物的减数分裂则产生了更多的配子，尽管这些易位的大小较小。在 UG.S0 植物的后代中，C1 染色体被 A1 染色体取代的频率出人意料地增加。• 我们得出结论，多倍体形成途径在遗传结果上存在差异。我们的研究为理解多倍体起源开辟了新的视角。
