As a contribution to the changing legislation and evolving societal attitudes concerning environmental issues, this project aims to enhance and manipulate the plants’ own natural defense mechanisms... Show moreAs a contribution to the changing legislation and evolving societal attitudes concerning environmental issues, this project aims to enhance and manipulate the plants’ own natural defense mechanisms against western flower thrips (WFT). Accordingly, an approach based on treatments of seeds (Solanum lycopersicum) and cuttings (Chrysanthemum morifolium) was undertaken to protect plants from their early critical young stage onwards. Known putative defense secondary metabolites were exogenously applied whereas, external application of plant hormones was explored as a means to trigger innate defense responses. Natural Deep Eutectic Solvents (NADES), as environmentally benign solvents, significantly improved the solubilizing properties of poorly-soluble insecticidal metabolites but did not enhance resistance against WFT. On the contrary, seed treatments with the ubiquitous plant hormone jasmonic acid (JA) appeared to induce cultivar dependent defenses as it only reduced silver damage in tomato cultivar Carousel. Sulfuric acid scarification, prior to JA seed incubation, significantly augmented the embryonic receptivity of a non-responsive cultivar thus, highlighting the importance of seed coat permeability. Moreover, we demonstrate that water dipping of indole-3-butyric acid (IBA)-coated chrysanthemum cuttings repeatedly reduced herbivory, both by thrips as well as by leaf miner. Show less
The general aim of the work described in this thesis is to help explain the variation in ageing by using the life history framework of B. anynana. Each chapter focuses on a different aspect of the... Show moreThe general aim of the work described in this thesis is to help explain the variation in ageing by using the life history framework of B. anynana. Each chapter focuses on a different aspect of the life history, together giving a complete picture of the origins of variation in ageing in this species. A central theme to every chapter is the relative influence of genes, the environment, and how they related to plasticity. A summarising discussion of all chapters, and a perspective on how the ideas in this thesis will contribute to ageing research in the future is also included. Show less
