Correlations of polyploidy, apomixis and alpine environmental gradients

In a recent article published in AoB PLANTS, Schinkel et al. present a study on geographical parthenogenesis, an enigmatic and much disputed phenomenon that involves closely related sexual and apomictic (asexually reproducing) taxa displaying largely divergent distribution patterns. Based on a large sampling of natural populations of Ranunculus kuepferi, their study is the first quantitative, population-based assessment of mode of reproduction throughout the Alps to test for correlations with elevation and geographical distance patterns.

Geographical distribution of Ranunculus kuepferi reproduction modes of analyzed populations on a map of the European Alps with elevation model.
Geographical distribution of Ranunculus kuepferi reproduction modes of analyzed populations on a map of the European Alps with elevation model. Pie diagrams indicate proportions of sexual (white) and apomictic seed (black) formation within the populations, diploids with apomicts are marked by an asterisk. Cytotypes: 2×, diploid populations; 4×, tetraploid populations; mixed, populations consisting of two or more different cytotypes, including triploids.

Surprisingly, the authors found high variance in the modes of reproduction among cytotypes and provide the first evidence of apomixis in diploid natural populations. Furthermore, a significant correlation between ploidy and elevation was found, as well as correlations between mode of reproduction and environmental gradients.

Reference

Schinkel, C. C. F., Kirchheimer, B., Dellinger, A. S., Klatt, S., Winkler, M., Dullinger, S., & Hörandl, E. (2016). Correlations of polyploidy and apomixis with elevation and associated environmental gradients in an alpine plant. AoB Plants, 8, plw064. http://dx.doi.org/10.1093/aobpla/plw064