| Summary: | 碩士 === 國立臺北教育大學 === 自然科學教育學系碩士班 === 96 === Abstract
In this study, 553 soil and 27 dung samples were collected from Taiwan. Totally, 47 Coemansia strains were isolated from soil and 2 strains from dung. Based on morphological characters, 11 species, Coemansia aciculifera、C. furcata、C. interrupta、C. linderi、C. pectinata、C. sp.1、C. sp.2、C. sp.3、C. sp.4、C. sp.5 and C. sp. nov., are classified. Molecular biotechnology including polymerase chain reaction (PCR), gene cloning and sequencing were used to obtain the sequences of LSU-D1/D2 and ITS region (ITS1-5.8S-ITS2) of ribosomal DNA (rDNA). Taxonomic groups generating from molecular analysis of these two gene regions of rDNA are consistant with the groups based on morphological characters. Also, each species can be separated into an individual clade on phylogenetic trees. The intraspecific similarity of LSU-D1/D2 of Coemansia is 99-100%, and the interspecific similarity among Coemansia species was lower than 97%. On the other hand, the intraspecific similarity of ITS region of Coemansia species is 91-100 %, and the interspecific similarity among Coemansia was lower than 89%. The ITS region sequence of rDNA is more variable even in the same strain. Between two genera Coemansia and Linderina, the similarity of LSU- D1/D2 is 63-69% and which of ITS region is 34-53%. The species isolated from dung and soil are suspected to belong to different genera, owing to the similarity value of LSU-D1/D2 rDNA sequence between these two groups is 66-68% and which of ITS region is 33-44%. Besides, the new species with two spore types is proposed to be a new genus, due to the similarity of LSU-D1/D2 between it and the other species isolated from soil is 70-73% and which of ITS region is 39-44%. Consequently, a key of the genus Coemansia in Taiwan is constructed based on combined data from molecular approach of LSU-D1/D2 of rDNA and the morphological characters.
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