碩士 / 國立臺東大學 / 生命科學研究所 / 94 / The external morphology of the species in the genus Grateloupia is very variable. The thalli are composed by single or few, soft blades to bush, rigid, terete branches, or by luxuriant to cartilaginous blades, or by from regular to irregular pinnate proliferations. The previous studies on the taxonomy of Grateloupia from Taiwan were mainly focused on the differences in the vegetative structures. As the results, many species were wrongly named synonymously or homonymously. In this study, I used two approaches (the cystocarp development and rbcL sequence analysis) to clarify the taxonomic problems occurred in the species of Grateloupia from Taiwan and to infer their phylogenetic relationships between the species from Taiwan and the other species of Grateloupia from around the world. In this study, the molecular analyses showed that there are seven species of Grateloupia present in the waters of Taiwan. Among the seven species I found, four are new species (G. gelidioides sp. nov., G. lewisii sp. nov., P. huangii sp. nov. and P. taiwanensis sp. nov.). Grateloupia gelidioides and G. lewisii are reported as new to science as the first time, whereas P. huangii was mis-identified as “G. okamurae” and G. “filicina” and P. taiwanensis was misapplied to G. “carnosa”、G. “livida” and G. “sparsa” before. The record of G. ramossissima is confirmed and another two species treated here as Grateloupia sp. 1 and Prionitis sp. 1 are also found for the first time. Because of lacking female specimens for a detailed study, the two unnamed species call for a further study. In addition, as shown in the phylogenetic tree inferred from the rbcL sequences of the species of Grateloupia from Taiwan and worldwide, they can be divided into two subclades. One is called as Grateloupia sensu stricto subclade, consisting of the generic type of Grateloupia, G. filicina from Italy, G. gelidioides, G. lewisii., G. ramossissima and Grateloupia sp. 1 from Taiwan, whereas the other is treated as Prionitis sensu stricto subclade, which includes the generic type of Prionitis, P. lanceolata from California, USA, and P. huangii, P. taiwanensis and Priontis sp. 1 from Taiwan. Furthermore, based on the observations of the cystocarp development, there are two types of the formation of the pericarp after fertilization: 1) the pericarp is not formed by the ampular filaments, which are undivided or little differentiated, but is generated by growth of filamentous, medullar and transformed inner cortical cells. The species possessing the first type of pericarp are G. gelidioides, G. lewisii and G. ramossissima; 2) the pericarp is formed by the divided, differentiated ampullar filaments after fertilization along with filamentous medullar and transformed inner cortical cells. This species having the second type of pericarp include P. huangii and P. taiwanensis. Therefore, I conclude that the behavior of the ampular filaments after fertilization can be used as important features for separating the species currently placed in the genus Grateloupia into two different two genera, Grateloupia and Prionitis, which is currently sunken under the genus Grateloupia, in addition to the architecture of the ampullar filaments. In the true species of Grateloupia, the pericarp is mainly formed by transformed inner cortical and filamentous medulla cells. Nevertheless, the pericarp in the true species of Prionitis is consisting of the differentiated ampullar filaments, transformed inner cortical cells and medulla filaments. As the results shown above, this research successfully resolved the long standing, taxonomic problem of the genera Grateloupia and Prionitis, which can not be fully explained by rbcL sequence analysis or vegetative, morphological studies, by carefully examining the cystocarp development.
| Identifer | oai:union.ndltd.org:TW/099NTTU0105001 |
| Date | January 2006 |
| Creators | Liang, Hongyan, 梁宏彥 |
| Contributors | Lin, Sioumei, 林綉美 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 170 |
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