Outbreeding depression and breeding system evolution in small, remnant populations of Primula vulgaris: consequences for genetic rescue
Outbreeding depression and breeding system evolution in small, remnant populations of Primula vulgaris: consequences for genetic rescue
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DOI：
10.1007/s10592-017-1031-x
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发表时间：
2018-06-01
影响因子：
2.2
通讯作者：
Oostermeijer, J. Gerard B.
中科院分区：
文献类型：
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作者：
Barmentlo, S. Henrik;Meirmans, Patrick G.;Oostermeijer, J. Gerard B.
许多物种遭受人类活动造成的生境破碎化。由此产生的小而孤立的种群更容易灭绝，除其他外，由于遗传侵蚀，近交衰退和阿莱效应。基因拯救可以帮助缓解这些问题，但可能会导致远系繁殖抑郁症。我们评估了后代的健身自交和异交内和之间的三个非常小的和孤立的残余群体的异柱植物报春。我们使用这些种群的温室生长后代来测试几个健身组件。一个群体被固定为针型，并与田间的另一个群体异交以获得种子。利用微卫星标记研究了亲本和子代群体的遗传多样性。结果表明，在结实率、种子重量和累积适合度等性状上，存在着形态和群体特异性杂种优势、近交衰退和异交衰退。最高的健身观察到在外地异交的F1-人口，这也表明随后的人口之间（回）杂交远交抑郁症。尽管远系繁殖的抑郁症，健身仍然相对较高。近交系数表明，后代的近交比他们的父母群体。后代杂合性和近亲繁殖系数与观察到的健身。一个种群是同型花柱进化的，表现出一种具有细长花柱和高度自主的果实和种子集的螺纹形态。这对遗传拯救等保护策略具有重要意义，因为交配系统将通过引入同型体而改变。
Many species suffer from anthropogenic habitat fragmentation. The resulting small and isolated populations are more prone to extinction due to, amongst others, genetic erosion, inbreeding depression and Allee-effects. Genetic rescue can help mitigate such problems, but might result in outbreeding depression. We evaluated offspring fitness after selfing and outcrossing within and among three very small and isolated remnant populations of the heterostylous plant Primula vulgaris. We used greenhouse-grown offspring from these populations to test several fitness components. One population was fixed for the pin-morph, and was outcrossed with another population in the field to obtain seeds. Genetic diversity of parent and offspring populations was studied using microsatellites. Morph and population-specific heterosis, inbreeding and outbreeding depression were observed for fruit and seed set, seed weight and cumulative fitness. Highest fitness was observed in the field-outcrossed F1-population, which also showed outbreeding depression following subsequent between-population (back)crossing. Despite outbreeding depression, fitness was still relatively high. Inbreeding coefficients indicated that the offspring were more inbred than their parent populations. Offspring heterozygosity and inbreeding coefficients correlated with observed fitness. One population is evolving homostyly, showing a thrum morph with an elongated style and high autonomous fruit and seed set. This has important implications for conservation strategies such as genetic rescue, as the mating system will be altered by the introduction of homostyles.