Transcriptome analysis for discovering candidate genes involve in embryogenesis in coconut (Cocos nucifera L.) through 454 pyrosequencing

Coconut, Cocos nucifera L. is a major plantation crop, which ensures income for millions of people in the tropical region. Detailed molecular studies on zygotic embryo development would provide valuable clues for the identification of molecular markers to improve somatic embryogenesis. Since there is no ongoing genome project for this species, coconut expressed sequence tags (EST) would be an interesting technique to identify important coconut embryo specific genes as well as other functional genes in different biochemical pathways. The goal of this study was to analyse the ESTs by examining the transcriptome data of the different embryo tissue types together with one somatic tissue. Here, four cDNA libraries from immature embryo, mature embryo, microspore derived embryo and mature leaves were constructed. cDNA was sequenced by the Roche-454 GS-FLX system and assembled into 32621 putative unigenes and 155017 singletons. Of these unigenes, 18651 had significant sequence similarities to non-redundant protein database, from which 16153 were assigned to one or more gene ontology categories. Homologue genes, which are responsible for embryo development such as chitinase, beta-1,3-glucanase, ATP synthase CF0 subunit, thaumatin-like protein and metallothionein-like protein were identified among the embryo EST collection. Of the unigenes, 6694 were mapped into 139 KEGG pathways including carbohydrate metabolism, energy metabolism, lipid metabolism, amino acid metabolism and nucleotide metabolism. This collection of 454-derived EST data generated from different tissue types provides a significant resource for genome wide studies and gene discovery of coconut, a non-model species.

Essays on robust portfolio selection and pension finance

This thesis examines three different, but related problems in the broad area of portfolio management for long-term institutional investors, and focuses mainly on the case of pension funds. The first idea (Chapter 3) is the application of a novel numerical technique – robust optimization – to a real-world pension scheme (the Universities Superannuation Scheme, USS) for first time. The corresponding empirical results are supported by many robustness checks and several benchmarks such as the Bayes-Stein and Black-Litterman models that are also applied for first time in a pension ALM framework, the Sharpe and Tint model and the actual USS asset allocations. The second idea presented in Chapter 4 is the investigation of whether the selection of the portfolio construction strategy matters in the SRI industry, an issue of great importance for long term investors. This study applies a variety of optimal and naïve portfolio diversification techniques to the same SRI-screened universe, and gives some answers to the question of which portfolio strategies tend to create superior SRI portfolios. Finally, the third idea (Chapter 5) compares the performance of a real-world pension scheme (USS) before and after the recent major changes in the pension rules under different dynamic asset allocation strategies and the fixed-mix portfolio approach and quantifies the redistributive effects between various stakeholders. Although this study deals with a specific pension scheme, the methodology can be applied by other major pension schemes in countries such as the UK and USA that have changed their rules.