Cheang Chi-chiu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 126-136). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.vi / Contents --- p.viii / List of Tables --- p.xi / List of Figures --- p.xiii / Chapter CHAPTER 1: --- Introduction and Background --- p.1 / Chapter 1.1 --- Ecology and distribution of the genus Sargassum --- p.1 / Chapter 1.2 --- Classical taxonomy of the genus Sargassum and associated problems --- p.2 / Chapter 1.3 --- Recent approaches on taxonomic studies of Sargassum --- p.4 / Chapter 1.3.1 --- Morphological studies --- p.4 / Chapter 1.3.2 --- Genetic studies --- p.5 / Chapter 1.3.3 --- Integration of genetic and morphological studies --- p.7 / Chapter 1.4 --- Phylogeographic distribution and population dispersal --- p.8 / Chapter 1.5 --- Description of species --- p.11 / Chapter 1.6 --- Objectives --- p.14 / Chapter 1.7 --- Layout of the thesis --- p.15 / Chapter CHAPTER 2: --- Morphological Examination on Sargassum hemiphyllum --- p.17 / Chapter 2.1 --- Introduction --- p.17 / Chapter 2.2 --- Methodology --- p.18 / Chapter 2.2.1 --- Sampling locations and treatment of specimens --- p.18 / Chapter 2.2.2 --- Morphological measurement --- p.22 / Chapter 2.2.3 --- Data analysis and statistical tests --- p.28 / Chapter 2.3 --- Results --- p.31 / Chapter 2.3.1 --- Choosing parameters from preliminary results --- p.31 / Chapter 2.3.2 --- Analysis on the main data set --- p.40 / Chapter 2.3.2.1 --- Layout of the data set --- p.40 / Chapter 2.3.2.2 --- Spatially conservable vs. variable parameters --- p.51 / Chapter 2.3.3 --- Conservable morphological parameters- consensus of specimens --- p.58 / Chapter 2.3.4 --- Variable morphological parameters- variation among specimens based on categorical parameters --- p.58 / Chapter 2.3.5 --- Differentiation of populations based on measurable and numerical parameters --- p.63 / Chapter 2.4 --- Discussion --- p.74 / Chapter 2.4.1 --- Temporal vs. spatial variation in the morphology of Sargassum hemiphyllum --- p.74 / Chapter 2.4.2 --- Spatially conservable characters for the taxonomic identification of Sargassum hemiphyllum --- p.77 / Chapter 2.4.3 --- Variation within Sargassum hemiphyllum --- p.77 / Chapter 2.4.4 --- Variation along the biogeographical gradient --- p.79 / Chapter CHAPTER 3: --- Genetic Analysis of RbcL-S Spacer in Sargassum hemiphyllum --- p.82 / Chapter 3.1 --- Introduction --- p.82 / Chapter 3.2 --- Methodology --- p.87 / Chapter 3.2.1 --- Extraction and purification of DNA --- p.87 / Chapter 3.2.2 --- Polymerase chain reaction (PCR) and gel electrophoresis --- p.87 / Chapter 3.2.3 --- Purification of PCR product --- p.90 / Chapter 3.2.4 --- DNA sequencing --- p.90 / Chapter 3.2.5 --- RFLP study --- p.92 / Chapter 3.2.6 --- Sequence alignment and analysis --- p.92 / Chapter 3.3 --- Results --- p.93 / Chapter 3.3.1 --- Extraction and PCR amplification --- p.93 / Chapter 3.3.2 --- Pilot study --- p.97 / Chapter 3.3.3 --- RFLP study --- p.103 / Chapter 3.4 --- Discussion --- p.108 / Chapter 3.4.1 --- Suitability of RbcL-S spacer as genetic marker at population level --- p.108 / Chapter 3.4.2 --- Two clades vs. two varieties of S. hemiphyllum --- p.109 / Chapter 3.4.3 --- Reproductive barrier --- p.110 / Chapter CHAPTER 4: --- General Discussion --- p.113 / Chapter 4.1 --- Morphological and genetic data- consistence or conflict --- p.113 / Chapter 4.2 --- Latitudinal gradient of seawater temperature in the Pacific NW --- p.115 / Chapter 4.3 --- Fluctuation in seawater salinity in the Pacific NW --- p.118 / Chapter 4.4 --- Possible initiation of speciation --- p.122 / Chapter 4.5 --- Works to be done in the future --- p.123 / References --- p.126