Genetic variation in anti-herbivore chemical defences in an invasive plant
Article first published online: 23 APR 2012
© 2012 The Authors. Journal of Ecology © 2012 British Ecological Society
Journal of Ecology
Volume 100, Issue 4, pages 894–904, July 2012
How to Cite
Wang, Y., Siemann, E., Wheeler, G. S., Zhu, L., Gu, X. and Ding, J. (2012), Genetic variation in anti-herbivore chemical defences in an invasive plant. Journal of Ecology, 100: 894–904. doi: 10.1111/j.1365-2745.2012.01980.x
- Issue published online: 15 JUN 2012
- Article first published online: 23 APR 2012
- Received 3 January 2012; accepted 27 March 2012 Handling Editor: Martin Heil
- constitutive and inducible defences;
- evolution of increased competitive ability;
- invasion ecology;
1. Plants produce a variety of secondary metabolites such as flavonoids or tannins that vary in effectiveness against different herbivores. Because invasive plants experience different herbivore interactions in their introduced versus native ranges, they may vary in defence chemical profiles.
2. We subjected tallow tree (Triadica sebifera) seedlings from native (China) and introduced (US) populations to induction by leaf clipping or one of three Chinese caterpillars (two generalists and one specialist). We measured the concentrations of five flavonoids and four tannins in leaves produced before or after damage. We measured growth of caterpillars fed these leaves from plants of each induction treatment or undamaged controls.
3. Plants from introduced populations had higher flavonoids and lower tannins than plants from native populations, especially in new leaves following induction. Caterpillar responses to changing chemical concentrations varied in direction and strength, so overall performance varied from significantly lower (generalist Grammodes geometrica), unchanged (generalist Cnidocampa flavescens), to significantly higher (specialist Gadirtha inexacta) on introduced populations.
4. Synthesis. Together, such a trade-off in secondary metabolism in invasive plants and the effect on herbivores suggest divergent selection may favour different chemical defences in the introduced range where co-evolved natural enemies, especially specialists, are absent.