碩士 / 國立臺灣大學 / 園藝學研究所 / 91 / English ivy (Hedera helix L.), a perennial Araliaceae plant, originates in temperate and subtropical zones of Europe, Northern Africa, and Western Asia. Because English ivy has showy leaves and morphology, making it as an important foliage and landscape plant. The shoot in juvenile stage tends to sprouting, which results in a large number of cultivars with different growing habits. This study aimed 1)to investigate the phenotypic behaviors 2) to measure the effects of irradiance and temperature on growth and photosynthesis of different cultivars, and 3) to determine growth response to nitrogen concentration with the ebb-and-flow system.
According to the growth responses to shading experiment, measuring of light saturation point(LSP), and light compensation point(LCP), the irradiance requirements of English ivy cultivars were suggested. The shoot length and node number of ‘Kolibri’ were not affected by different shading irradiance. The percentages of leaf variegation were similar in plants under 76% shading and without shading. The LCP of ‘Kolibri’ was relatively low, suggesting a low irradiance tolerance. The cultivar ‘Dark Pittsburg’ has a low LCP, which may explain why the growth was not reduced by low light intensity conditions. The cultivar ‘Evergreen’ required shading to increase growth. The cultivar ‘Golden Child’ had a higher LSP, but required proper shading to prevent the decrease in dry weight and leaf variegation. ‘Mini Adam’ reached the maximum dry weight and leaf variegation under 60％ shading. ‘Ingelise’ has a high LCP, all plants died under 84％ shading, and the leaf variegation decreased under 40% or more shading treatments. Both the LSP and the LCP of ‘Evergreen’ were low, suggesting that ‘Evergreen’ required less light intensity and could grow well under low irradiance. This was supported by the growth response to shading.
High temperature at 35/30℃ reduced the growth of English ivies in fewer roots, leaf area, number of new leaves and less root and shoot dry weight, and days to the first leaf unfolding. The responses of leaf variegation to irradiance were cultivar dependent. The cultivars ‘Golden Child’, ‘Dark Pittsburg’, ‘Ovata’, and ‘Lady Kay’ grew well under 30/25℃, while ‘Hvid Mein Hertz’, ‘Kolibri’, ‘Ingelise’, ‘Mini Adam’, and ‘Evergreen’ preferred the temperature of 25/20℃, and maximum growth of ‘Mint Kolibri’ at 20/15℃. A negative linear relationship existed between the dry weight ratio (growth at 35/30℃: 25/20℃) and the relatively injury at 50℃. There was a positive linear relationship between delayed days to the first leaf unfolding at 35/30℃and relative injury at 50℃. These results suggest that the cell membrane thermotolerance could be a rapid and easy method to measure the heat tolerance of English ivy cultivars.
Three groups could be classified according to the growth responses to different nitrogen concentration with ebb-and-flow irragation. The first group included ‘Hvid Mein Hertz’, ‘Golden Child’, ‘Evergreen’, and ‘Lady Kay’, with maximum growth at 2 to 4 mM N. The second group included ‘Ingelise’, ‘Mini Adam’, and ‘Dark Pittsburg’, with peak growth at 8 mM. The third group involved ‘Mint Kolibri’ and ‘Ovata’ could accommodate with nitrogen concentration between 2 and 8 mM.
| Identifer | oai:union.ndltd.org:TW/091NTU00378037 |
| Date | January 2003 |
| Creators | Pu-Yun Hsu, 徐步雲 |
| Contributors | Der-Ming Yeh, 葉德銘 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 105 |
Page generated in 0.0118 seconds