博士 / 國立中興大學 / 生命科學系所 / 98 / Hydrogen cyanamide (HC) has been applied to break bud and seed dormancy in several crops. The effect of HC (0.5 and 1.0 M) on sprouting percentage, bud length, number of leaves and plant height of calla lily (Zantedeschia spp.) was investigated in the two cultivars Florex Gold and Pacific Pink. Results showed that tuber dormancy was released after 20 min treatment with 0.5 or 1.0 M concentration of the HC when the tubers were embedded into moistened media and moved into an incubator at 20℃for 20 days. The HC-treated tubers in two cultivars produced more sprouts, plant height and number of leaves after 8 week planting in greenhouse, compared with the control (untreated). Although both concentrations of HC release bud dormancy, HC at 0.5 M was the more suitable treatment. Meanwhile, sprouting time of HC-treated tubers in Florex Gold was 4 days earlier than that in Pacific Pink. Calla lily tubers from summer season producted with the tubers have long dormancy period.
Carbohydrates were measured in apical region, medulla region and cortex region from Pacific Pink to determine whether concentrations change after HC treated （0.5 M）colored calla lily tubers. Obsevations on paraffin-embedded sections of colored calla lily tuber tissues treated with 0.5 M HC for 2 days showed imbibition formed in medulla region and cortex region cells. Starch degraded from medulla by inner of vascular ring. HPLC analysis showed that decreases in the level of sucrose within medulla region, and change in maltose had occurred. In addition, the level of glucose and fructose were increased with increasing activities of meristem and tuber sprouting.
The response of the antioxidant enzymes activities and metabolites of ascorbate-glutatione pathway to oxidative stress caused by HC was studied in Pacific Pink cultivar treated with 0.5 M HC at dark conditions for 0-16 days. Total superoxide dismutase (SOD), dehydroascorbate reductase (DHAR) and glutathione reductase (GR) enzyme activities increase under HC induced, whereas monodehydroascorbate reductase (MDHAR) enzyme activity decreased. Therefore, these results infer reactive oxygen species (ROS) induced by HC treatment in colored calla lily belong to the metabolisms of SOD and ascorbate-glutatione cycle. On the other hand, we also infer ascorbate-glutatione cycle may be a DHAR reduced pathway because MDHAR is a negative regulation. However, MDHAR played a role in tuber dormancy release needs more research.
| Identifer | oai:union.ndltd.org:TW/098NCHU5105033 |
| Date | January 2010 |
| Creators | Ting-Lin Chang, 張定霖 |
| Contributors | Song-Iuan Liaw, 廖松淵 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 80 |
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