Van Rossum Fabienne, Raspé Olivier, Vandelook Filip
Meise Botanic Garden Meise Belgium.
Service général de l'Enseignement supérieur et de la Recherche scientifique Fédération Wallonie-Bruxelles Brussels Belgium.
Ecol Evol. 2021 Jun 3;11(13):8640-8653. doi: 10.1002/ece3.7677. eCollection 2021 Jul.
Knowing species' breeding system and mating processes occurring in populations is important not only for understanding population dynamics, gene flow processes, and species' response to climate change, but also for designing control plans of invasive species. , a widespread biennial herbaceous species showing high morphological variation and wide ecological amplitude, can become invasive outside its distribution range. A mixed-mating system may be expected given the species' floral traits. However, autonomous selfing is considered as a common feature. Genetic variation and structure, and so population mating processes, have not been investigated in wild populations. We developed 15 polymorphic microsatellite markers to quantify genetic variation and structure in . . To investigate whether selfing might be the main mating process in natural conditions, we sampled three generations of plants (adult, F1, and F2) for populations from the UK, Spain, Belgium, Germany, and Sweden, and compared open-pollinated with outcrossed hand-pollinated F2 progeny. The highly positive Wright's inbreeding coefficient ( ) values in adults, F1, and open-pollinated F2 progeny and the low values in outcross F2 progeny supported autonomous selfing as the main mating process for in wild conditions, despite the presence of attractive signals for insect pollination. Genetic differentiation among samples was found, showing some western-eastern longitudinal trend. Long-distance seed dispersal might have contributed to the low geographic structure. Local genetic differentiation may have resulted not only from genetic drift effects favored by spontaneous selfing, but also from ecological adaptation. The presence of duplicate loci with disomic inheritance is consistent with the hypothesis of allotetraploid origin of . The fact that most microsatellite markers behave as diploid loci with no evidence of duplication supports the hypothesis of ancient polyploidization. The differences in locus duplication and the relatively high genetic diversity across range despite spontaneous autonomous selfing suggest multiple events of polyploidization.
了解物种的繁殖系统以及种群中发生的交配过程不仅对于理解种群动态、基因流动过程和物种对气候变化的响应很重要，而且对于设计入侵物种的控制计划也很重要。[物种名称]是一种广泛分布的两年生草本植物，表现出高度的形态变异和广泛的生态幅度，在其分布范围之外可能会成为入侵物种。鉴于该物种的花部特征，可能预期其为混合交配系统。然而，自动自花授粉被认为是一个常见特征。野生种群中的遗传变异和结构，以及种群交配过程尚未得到研究。我们开发了15个多态性微卫星标记来量化[物种名称]的遗传变异和结构。为了研究自花授粉是否可能是自然条件下的主要交配过程，我们对来自英国、西班牙、比利时、德国和瑞典的种群的三代植物（成年植株、F1和F2）进行了采样，并将自由授粉的F2后代与异交人工授粉的F2后代进行了比较。成年植株、F1和自由授粉的F2后代中高度正的赖特近交系数（ ）值以及异交F2后代中的低值支持了自动自花授粉是[物种名称]在野生条件下的主要交配过程，尽管存在吸引昆虫授粉的信号。在样本中发现了遗传分化，呈现出一些东西向的纵向趋势。远距离种子传播可能导致了低地理结构。局部遗传分化可能不仅是由于自发自花授粉所青睐的遗传漂变效应，还可能是由于生态适应。具有二体遗传的重复位点的存在与[物种名称]异源四倍体起源的假说是一致的。大多数微卫星标记表现为二倍体位点且没有重复证据这一事实支持了古老多倍体化的假说。位点重复的差异以及尽管存在自发自动自花授粉但[物种名称]分布范围内相对较高的遗传多样性表明存在多次多倍体化事件。
