Cheung, Man Kit. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 81-93). / Abstracts in English and Chinese. / Abstract (English) --- p.I / Abstract (Chinese) --- p.III / Acknowledgements --- p.V / Table of contents --- p.VI / List of figures --- p.IX / List of tables --- p.XI / List of Appendices --- p.XII / Chapter Chapter 1. --- General introduction --- p.1 / Chapter 1.1. --- Picoeukaryotes --- p.1 / Chapter 1.2. --- Conventional characterization techniques --- p.1 / Chapter 1.3. --- Cloning and sequencing approach --- p.3 / Chapter 1.3.1. --- Applications in prokaryotic plankton --- p.3 / Chapter 1.3.2. --- Applications in eukaryotic picoplankton --- p.3 / Chapter 1.4. --- Variations in diversity with environmental factors --- p.5 / Chapter 1.5. --- Study site --- p.6 / Chapter 1.6. --- Objectives --- p.8 / Chapter Chapter 2. --- Materials and methods --- p.9 / Chapter 2.1. --- Study site --- p.9 / Chapter 2.2. --- Sample collection --- p.9 / Chapter 2.3. --- DNA extraction and 18S rRNA gene amplification --- p.11 / Chapter 2.4. --- Clone library construction and screening --- p.12 / Chapter 2.5. --- Sequencing and phylogenetic analysis --- p.13 / Chapter 2.6. --- Statistical analyses --- p.14 / Chapter Chapter 3. --- Results --- p.15 / Chapter 3.1. --- Hydrological parameters of study site --- p.15 / Chapter 3.2. --- Clone libraries --- p.15 / Chapter 3.3. --- Higher-level taxonomic distribution --- p.21 / Chapter 3.4. --- Phylogenetic affiliations of OTUs --- p.22 / Chapter 3.4.1 --- Alveolates --- p.35 / Chapter 3.4.2 --- Stramenopiles --- p.36 / Chapter 3.4.3 --- Rhizaria --- p.36 / Chapter 3.4.4 --- Other lineages --- p.37 / Chapter 3.4.5 --- Novel higher-level groups --- p.38 / Chapter 3.5. --- Diversity estimates of picoeukaryotes --- p.39 / Chapter Chapter 4. --- Discussion --- p.42 / Chapter 4.1. --- Picoeukaryotic diversity --- p.42 / Chapter 4.1.1 --- Overall diversity --- p.42 / Chapter 4.1.2 --- Diversity of individual taxonomic groups --- p.44 / Chapter 4.1.2.1 --- Most represented lineages --- p.44 / Chapter 4.1.2.2 --- Other photosynthetic lineages --- p.52 / Chapter 4.1.2.3 --- Other non-photosynthetic lineages --- p.55 / Chapter 4.1.2.4 --- Novel higher-level lineages --- p.56 / Chapter 4.2. --- Spatial and seasonal variations of picoeukaryotes --- p.58 / Chapter 4.2.1 --- Spatial variations --- p.59 / Chapter 4.2.1.1 --- Compositional variations --- p.60 / Chapter 4.2.1.2 --- Variations in diversity --- p.61 / Chapter 4.2.2 --- Seasonal variations --- p.65 / Chapter 4.2.2.1 --- Compositional variations --- p.65 / Chapter 4.2.2.2 --- Variations in diversity --- p.66 / Chapter 4.3. --- Methodological aspects --- p.67 / Chapter 4.3.1 --- Sample collection --- p.67 / Chapter 4.3.2 --- PCR amplification --- p.68 / Chapter 4.3.3 --- Cloning and RFLP screening --- p.69 / Chapter 4.3.4 --- Statistical estimates --- p.71 / Chapter 4.3.5 --- Future directions --- p.71 / Chapter Chapter 5. --- General conclusion --- p.73 / References --- p.81