Invasive and native Rhododendron ponticum populations: is there evidence for genotypic differences in germination and growth?

• DOI: 10.1111/j.0906-7590.2005.03967.x
• Publication Date: 2005-07-15T17:36:13Z
• Authors: Alexandra Erfmeier; Helge Bruelheide
• Keywords: 0106 biological sciences; 15. Life on land; 01 natural sciences

Previous studies have shown that the invasive spread of Rhododendron ponticum in British Isles is influenced by more favourable environmental conditions new territory than species’ home range. In this study, we asked whether invasion success might also involve a genotypic background for higher growth and germination rates populations. We tested hypotheses populations absolute rates, germinate faster exhibit rates. present data from greenhouse climate chamber experiments with seed material cuttings six each native Georgian, Spanish Irish subjected to different temperature environments. There were no differences maximum rate optimum between origins. found significant velocity seeds responding most rapidly all treatments. Accordingly, experiment origins had highest relative environments tested. Our results provide evidence genetic shift towards an increased investment rate. Both traits would contribute explaining range expansion. The underlying evolutionary mechanisms are discussed, including possibility hybridisation or ecological release hitherto experienced constraints area.