Demographic consequences of inbreeding and outbreeding in Arnica montana: a field experiment
Demographic consequences of inbreeding and outbreeding in Arnica montana: a field experiment
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蒙大拿州山金车近交和远交的人口统计后果：田间实验
DOI：
10.1046/j.1365-2745.2002.00703.x
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发表时间：
2002
影响因子：
5.5
通讯作者：
Hans C. M. den Nijs
中科院分区：
文献类型：
--
作者：
S. Luijten;M. Kéry;J. Oostermeijer;Hans C. M. den Nijs
1 人群的遗传构成可能会显着影响人口统计学。创始种群或孤立的残余物可能会表现出近交衰退，而已建立的种群可以强烈适应当地环境。如果杂合性水平恢复（杂种优势），种群之间的基因交换可以导致更好的性能，或者如果共适应的基因复合体被破坏（远交衰退），则可以导致性能下降。 2 对自交不亲和的多年生山金车蒙大拿（菊科）的五个种群进行了近交以及种群内和种群间异交的人口统计后果的分析，使用小种群和大种群作为后者的供体。我们分析了种子产量和种子重量，并监测了在为期 4 年的田间实验中作为种子和 4 周龄幼苗引入的后代的生长、存活和开花。 3 自交后结实率降低可能是由于自交不亲和系统而不是近交抑制。群体间杂交后，结籽率显着增加，这是由于其中一个小群体的低配偶可用性得到缓解。 4 作为幼苗引入的植物的生长速率观察到显着的近交抑制。我们发现以种子引入的植物的开花概率具有显着的杂种优势，但对于以幼苗引入的植物，幼苗大小和开花概率的杂种优势仅略微显着。没有观察到近交衰退。 5 这项研究的结果对于小型残余人口的强化措施非常重要。人群之间所有测量的健康成分的显着差异表明，使用来自多个人群的材料可以最好地实现强化。 6 与种子相比，观察到的幼苗存活率更高，这表明种植个体比播种更好。然而，播种更容易、更便宜，并且更有可能在适应不良的基因型为下一代做出贡献之前将其消除。
1 The genetic constitution of populations may significantly affect demography. Founder populations or isolated remnants may show inbreeding depression, while established populations can be strongly adapted to the local environment. Gene exchange between populations can lead to better performance if heterozygosity levels are restored (heterosis), or to reduced performance if coadapted gene complexes are disrupted (outbreeding depression). 2 Five populations of the self‐incompatible perennial Arnica montana (Asteraceae) were analysed for the demographic consequences of inbreeding and of intra‐ and interpopulation outcrossing, using both small and large populations as donors for the latter. We analysed seed production and seed weight and monitored growth, survival and flowering of offspring introduced as seeds and as 4‐week‐old seedlings in a 4‐year field experiment. 3 Reduced seed set after selfing was probably due to the self‐incompatibility system rather than to inbreeding depression. There was a significant increase for seed set after interpopulation crosses, which resulted from the alleviation of low mate availability in one of the small populations. 4 Significant inbreeding depression was observed for growth rates of plants introduced as seedlings. We found significant heterosis for flowering probability of plants introduced as seeds, but for plants introduced as seedlings, heterosis for seedling size and flowering probability was only marginally significant. Outbreeding depression was not observed. 5 The results of this study are important for reinforcement measures in small, remnant populations. Significant differences among populations for all measured fitness components suggest that reinforcement is best achieved using material from several populations. 6 The observed higher survival of seedlings as compared with seeds suggests that it is better to plant individuals than to sow. Sowing, however, is easier and cheaper, and was more likely to eliminate poorly adapted genotypes before they contribute to the next generation.