Abstract Interspecific hybridization has been fundamental in plant evolution. Nevertheless, the fate of hybrid zones throughout the generations remains poorly addressed. We analyzed a pair of recently diverged, interfertile, and sympatric Petunia species to ask what fate the interspecific hybrid population has met over time. We analyzed the genetic diversity in two generations from two contact sites and evaluated the effect of introgression. To do this, we collected all adult plants from the contact zones, including canonicals and intermediary colored individuals, and compared them with purebred representatives of both species based on seven highly informative microsatellite loci. We compared the genetic diversity observed in the contact zones with what is seen in isolated populations of each species, considering two generations of these annual species. Our results have confirmed the genetic differentiation between the species and the hybrid origin of the majority of the intermediary colored individuals. We also observed a differentiation related to genetic variability and inbreeding levels among the populations. Over time, there were no significant differences per site related to genetic diversity or phenotype composition. We found two stable populations kept by high inbreeding and backcross rates that influence the genetic diversity of their parental species through introgression.

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密切相关的植物物种之间的次生接触区的命运可能如何？

摘要 种间杂交是植物进化的基础。然而，世代相传的杂交区的命运仍然没有得到很好的解决。我们分析了一对最近分化的、可生育的和同域的矮牵牛属植物，以了解随着时间的推移，种间杂种种群的命运如何。我们分析了来自两个接触位点的两代遗传多样性并评估了基因渗入的影响。为此，我们从接触区收集了所有成年植物，包括规范和中间有色个体，并基于七个高度信息化的微卫星位点将它们与两个物种的纯种代表进行比较。我们将接触区观察到的遗传多样性与每个物种的孤立种群中观察到的遗传多样性进行了比较，考虑到这些一年生物种的两代。我们的结果证实了大多数中间有色个体的物种和杂种起源之间的遗传差异。我们还观察到与种群间遗传变异和近交水平相关的分化。随着时间的推移，每个位点在遗传多样性或表型组成方面没有显着差异。我们发现两个稳定的种群由高近交和回交率保持，这些种群通过基因渗入影响其亲本物种的遗传多样性。我们还观察到与种群间遗传变异和近交水平相关的分化。随着时间的推移，每个位点在遗传多样性或表型组成方面没有显着差异。我们发现两个稳定的种群由高近交和回交率保持，这些种群通过基因渗入影响其亲本物种的遗传多样性。我们还观察到与种群间遗传变异和近交水平相关的分化。随着时间的推移，每个位点在遗传多样性或表型组成方面没有显着差异。我们发现两个稳定的种群由高近交和回交率保持，这些种群通过基因渗入影响其亲本物种的遗传多样性。