碩士 / 國立臺灣海洋大學 / 海洋生物研究所 / 107 / Information on the diversity of fungi associated with macroalgae is lacking. Previous studies only focused on fungi of selected species of brown, green and red algae. This study, therefore, investigates the diversity of fungi associated with Pterocladiella capillacea, a dominant red alga in northern Taiwan, using a culture-dependent technique and a metabarcoding approach. For isolation, mycelia growing out from washed healthy and dead thalli on GYPS (glucose-yeast extract-peptone seawater agar) and SWA (seawater agar) media were subcutlured onto CMAS (cornmeal seawater agar) medium and grouped into colony morphotypes. ITS (internal transcribed spacers of the rDNA) and LSU (large subunit of the rDNA) of the fungi were sequenced and compared with reference sequences in NCBI for identification. For high-throughput sequencing, total RNA and DNA were extracted from freeze-dried Pterocladiella capillacea thalli. RNA was reverse-transcribed into cDNA, and together with the extracted total DNA, a region of the ITS1 (230−422 bp) of DNA and cDNA using a nested PCR approach was amplified for Illumina Miseq sequencing. For relative abundance (no. of a particular species / no. of total species 100 %), Ascomycota (88.75%) and Basidiomycota (11.25%) were the only phyla obtained from the isolation approach. For the metabarcoding analyses, unidentified fungi (75.04%) were dominant in the rDNA sequences, followed by Basidiomycota (16.23%) and Ascomycota (8.72%). Basidiomycota (52.31%) was dominant in the rRNA samples, followed by Ascomycota (40.56%) and Chytridiomycota (0.004%) while unidentified fungi constituted 7.13% of the total sequences. The dominant fungi from isolation based on relative abundance were Hypoxylon monticulosum (11.25%), Byssochlamys spectabilis (7.50%) and Emericella sp. (7.50%); Mycosphaerella sp. (2.49%), Malassezia globosa (1.73%) and Auricularia polytricha (1.23%) in the rDNA samples; Nigrospora sphaerica (12.52%), Peniophora sp.1 (9.23%) and Auricularia polytricha (8.09%) in the rRNA samples. Shannon’s diversity index (H’) suggests that the rRNA samples had the highest diversity (3.644), followed by the culturable collection of fungi (3.414) and the rDNA samples (2.077). These results collectively suggest that different methods uncovered different fungal diversity on the alga, and the Basidiomycota might play a symbiotic role with the red alga.
| Identifer | oai:union.ndltd.org:TW/107NTOU5270002 |
| Date | January 2019 |
| Creators | He,Chih-Chiao, 何止喬 |
| Contributors | Pang, Ka-Lai, 彭家禮 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 84 |
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