Gil's paper on population divergence in Iris atropurpurea published
- labsapir
- Jun 1, 2016
- 1 min read
Yardeni, G., N. Tessler, E. Imbert, and Y. Sapir. Reproductive isolation between populations of Iris atropurpurea is associated with ecological differentiation. Annals of Botany (DOI: 10.1093/aob/mcw139).
Abstract
• Background and Aims: Speciation is often described as a continuous dynamic process, expressed by different magnitudes of reproductive isolation (RI) among groups in different levels of divergence. Studying intraspecific partial RI can shed light on mechanisms underlying processes of population divergence. Intraspecific divergence can be driven by spatially stochastic accumulation of genetic differences following reduced gene flow, resulting increased RI with increased geographical distance, or by local adaptation, resulting increase RI with environmental difference.
• Methods: We tested for RI as a function of both geographical distance and ecological differentiation in Iris atropurpurea, an endemic Israeli coastal plant. We crossed plants in Netanya Iris Reserve population with plants from 14 populations across the species’ full distribution, and calculated RI and reproductive success based on fruit-set, seed-set, and fraction of seeds viability.
• Key Results: We found that total RI was not significantly associated with geographical distance, but significantly increased with ecological distance. Similarly, reproductive success of the crosses, estimated while controlling for the dependency of each component on the previous stage, significantly reduced with increased ecological distance.
• Conclusions: Our results indicate that the rise of post-pollination reproductive barriers in Iris atropurpurea is more affected by ecological differentiation between populations than by geographic distance, supporting the hypothesis ecological differentiation is predominant over isolation by distance and by reduced gene flow in this species. These findings also affect conservation management, such as genetic rescue, in the highly fragmented and endangered I. atropurpurea.
