Department of Ecology, University of Nijmegen, Toernooiveld 1, 6525 ED Nijmegen, Netherlands.
Am J Bot. 2004 Aug;91(8):1183-9. doi: 10.3732/ajb.91.8.1183.
Significantly different maternal line responses to inbreeding provide a mechanism for the invasion of a selfing variant into a population. The goal of this study was to examine the extent of family-level variation in inbreeding depression in the mixed-mating, perennial herb Scabiosa columbaria. Plants from one population were raised, and hand-pollinated to produce selfed and outcrossed progeny, and the effects of inbreeding depression on life-cycle traits were analyzed. Inbreeding depression significantly affected early life cycle traits. The pollination treatment by family interaction was significant for almost all traits, indicating a high family-level variation in inbreeding depression. The correlations between inbreeding depression values (e.g., percentage germination and flowering date, and flowering date and aboveground biomass) exhibited alternate signs, illustrating the type of association between inbreeding depression loci for different traits across the life cycle. Overall, it is concluded that the extent of among-family variation in inbreeding depression might allow a selfing variant of S. columbaria to invade an outcrossing population, though the pattern of correlations between inbreeding depression values might prevent effective purging of the deleterious genetic load.
显著不同的母系对近亲繁殖的响应为自交变体入侵种群提供了一种机制。本研究的目的是检验混合交配、多年生草本矢车菊属植物在家族水平上近亲繁殖衰退的程度。从一个种群中培育植物，并进行人工授粉，以产生自交和异交后代，并分析近亲繁殖衰退对生命周期特征的影响。近亲繁殖衰退显著影响早期生命周期特征。授粉处理与家族间的相互作用对几乎所有特征都具有显著影响，表明近亲繁殖衰退在家族水平上存在高度的变异性。近亲繁殖衰退值之间的相关性（例如，发芽率和开花日期、开花日期和地上生物量之间的相关性）呈现出交替的符号，说明了不同生命周期特征之间的近亲繁殖衰退基因座之间的关联类型。总体而言，结论是，矢车菊属植物在近亲繁殖衰退方面的家族间变异性程度可能允许自交变体入侵异交种群，尽管近亲繁殖衰退值之间的相关性模式可能会阻止有害遗传负荷的有效清除。
