Bariotakis Michael, Koutroumpa Konstantina, Karousou Regina, Pirintsos Stergios A
Department of Biology University of Crete Heraklion Greece.
Department of Biology University of Crete Heraklion Greece; Present address: Department of Systematic and Evolutionary Botany University of Zürich Zürich Switzerland.
Ecol Evol. 2016 Nov 16;6(24):8727-8739. doi: 10.1002/ece3.2560. eCollection 2016 Dec.
The role of environment and the relative significance of endogenous versus exogenous selection in shaping hybrid zones have been crucial issues in the studies of hybridization. Recent advances in ecological niche modeling (ENM) offer new methodological tools, especially in combination with the genotyping of individuals in the hybrid zone. Here, we study the hybrid zone between the widely known spices and ssp. in Crete. We analyze the genetic structure of both parental taxa and their hybrid × using AFLP markers on 15 sympatric and 12 allopatric populations and employ ecological niche modeling and niche similarity tests to study their niche patterns. We complement these analyses with seed viability measurements. Our study revealed that the hybridizing taxa and ssp. and the resulting genotypic classes showed geographical and environmental niche similarities based on the predictions of ENMs and the subsequent similarity tests. The occurrence of the hybrid zone is not directly dependent on environmental factors which favor the fitness of the hybrid compared to the parental taxa, but rather on aspects such as historical factors and management practices, which may contribute to the localization and maintenance of the contact zone between parental species. Our results suggest that if a minimum required niche differentiation between genotypic classes is not achieved, environmental dependence might not have a prominent role on the outcome of the hybridization.
在杂交研究中，环境的作用以及内源性选择与外源性选择在塑造杂交带方面的相对重要性一直是关键问题。生态位建模（ENM）的最新进展提供了新的方法工具，特别是与杂交带中个体的基因分型相结合时。在这里，我们研究了克里特岛广为人知的物种 和 亚种之间的杂交带。我们使用AFLP标记分析了15个同域种群和12个异域种群中两个亲本分类群及其杂种×的遗传结构，并采用生态位建模和生态位相似性测试来研究它们的生态位模式。我们通过种子活力测量对这些分析进行补充。我们的研究表明，基于ENM的预测和随后的相似性测试，杂交分类群 和 亚种以及由此产生的基因型类别显示出地理和环境生态位相似性。杂交带的出现并不直接依赖于与亲本分类群相比有利于杂种适应性的环境因素，而是取决于历史因素和管理实践等方面，这些因素可能有助于亲本物种之间接触带的定位和维持。我们的结果表明，如果基因型类别之间未实现最低要求的生态位分化，环境依赖性可能不会在杂交结果中发挥突出作用。
