Effects of slug herbivory on seedling recruitment in Brassica napus and B. rapa
Promotor: Prof.dr. P.G.L. Klinkhamer, Co-Promotor: T.J. de Jong
- M. Moshgani
- 07 May 2015
- Thesis in Leiden Repository
Crops may escape from the field and establish feral populations. Crops may also cross with wild plants. Both are points of concern for Genetically Modified crops. We study this problem for the crop oilseed rape (Brassica napus) and its wild relative B. rapa. Hybrids between the two species perform well in the lab, even under conditions of water stress. Seedlings of crop and hybrids are, however, vulnerable to attack by slugs. By excluding slugs from field plots we showed that slug herbivory causes a strong reduction of seedling survival. Slugs avoid seedlings with high glucosinolate (GS) content. Modern cultivars of B. napus are low in GS content, while wild B. rapa has a high GS content. By applying GS to leaf discs we showed that the aliphatic GS progoitrin repels the slugs, whereas the indole GS glucobrassicin had no effect, even at elevated concentrations. We reanalysed large two studies in which the slug Arion lusitanicus was presented with leaves of different plant species. Slugs preferred plant with low Dry Matter Content (high water content) and shade-intolerant plant with low Specific Leaf Area. These correlations provide useful leads for further experimental research.