博士 / 國立中央大學 / 生命科學系 / 107 / Herbaceous vegetation at sand coasts consists of specific plants which can tolerate high salinity,
wind and sand movements, and lack of nutrients, and are, therefore, important for coast protection and
preventing erosion, but are outcompeted in inland habitats. Although this vegetation in Taiwan on the
one hand is endangered by construction, tourism and other human activities, as well as rising sea level,
and on the other hand fungal endophytes are known to have a strong influence on the survival of plants
under such stress factors, few is known about the endophytes of tropical/subtropical coastal herbaceous
plants. The aim of the study was to detect and identify endophytic fungi of Vitex rotundifolia and
Ipomoea pes-caprae, two of the most common plants along the shore of Taiwan, and to analyze
whether fungi were specific to plant species, certain organ or tissues. The study on composition and
diversity of fungi from both plants provided new data about the geographical and host distribution of
fungi, led to the discovery of new species and new fungal records. New isolates and DNA data were
deposited for future systematic and biotechnological studies and applications. We isolated 1072 strains
comprising 76 species from 1782 plant fragments of Vitex rotundifolia and 885 strains comprising 140
species from 2304 fragments of Ipomoea pes-caprae, which were identified with genetic markers as
well as with morphology. These species most are new records for their hosts. Among these species,
Alpestrisphaeria sp. nov. was considered as new and was found only in roots and stems of V.
rotundifolia. Only Aspergillus terreus was a common species in the top three dominant species from
both plants. Fungal communities in I. pes-caprae differed significantly between natural coastal habitats
and artificial plantations in botanical gardens. In coastal habitats, potentially pathogenic fungi were
rarer than saprobic species, which might indicate the importance of saprobic endophytes in nutrient
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cycling particularly of decomposing leaves after sand burial. The data indicate that occurrence of
endophytic fungal species is driven by the habitat, plant species, and plant organ. Except for the study
of endophytic fungi, examples of ectophytic fungi were studied for addressing the question whether
there is a clear-cut demarcation between endophytic, parasitic and saprobic fungi. Corynespora
cassiicola was found as leaf pathogen on artificially planted V. rotundifolia, but not as endophyte in
wild populations. Dinemasporium spinificis, a first record from Taiwan, was found only as ectophytic
saprobe on Spinifix littoreus, but was not recorded as endophyte from this plant in previous studies.
| Identifer | oai:union.ndltd.org:TW/107NCU05105017 |
| Date | January 2019 |
| Creators | Yu-Hung Yeh, 葉昱宏 |
| Contributors | Roland Kirschner, Wei-Hsin Sun, 羅南德, 孫維欣 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 168 |
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