| Summary: | 碩士 === 國立中興大學 === 園藝學系所 === 101 === Lycoris sprengeri Comes ex Baker is a species of Amaryllidaceae. Herbs perennial, tunicate bulb. Leaves appearing in early spring. Vegetative growth period in Dongyin is from February to May. Tubular flower; perianth pink but apically blue. Flowering period in Dongyin is from August to September. Lycoris sprengeri is mainly native to provinces along the middle and lower reaches of Yangtze River, like Hubei, Anhui, Jiangsu, Shanghai, Zhejiang et al. in China. However, the rapid development of China''s riverside and coastal cities lead to the natural habitat of Lycoris sprengeri change rapidly in decrease of population size. Because of former military administration in Matsu, Dongyin has been lesser developed, and its north coast retains many original vegetation landscape. Thus, Dongyin preserves a large area for Lycoris sprengeri population, which is extremely valuable. Currently, there are nine habitats marked and surveyed in Dongyin, seven of these have Lycoris sprengeri distributed. Five experimental plots were established for annual survey of Lycoris sprengeri and associated plants in these seven habitats. These five experimental plots are Xiaoziao and Ziao in Dongyin island, Dongao, Houao and Qingshuiao in Xiyin island respectively. Associated plant species of Lycoris sprengeri, more than 29 species, are mostly short herbaceous plant and liana. And the seasonal succession of associated plants are obvious.
Originally, only Lycoris sprengeri and Lycoris radiata were thought to be native to Dongyin township. But in our study by morphology, foliage period, other characteristics and on-the-spot investagation, we found the natural hybrid, Lycoris × rosea Traub & Moldenke. And thus we determine there are four Lycoris species native to Dongyin. Lycoris sprengeri native to Dongyin has various flower shapes and colors, but individuals with non-typical features of Lycoris sprengeri were found, like albino individual and flower with reflexed apex of tepals. The shape and color of natural hybrid populations of Lycoris × rosea and Lycoris × haywardii are diverse. Basically, we can distinguish these two species by flower shape and the extent of stamens protruding tepals. There are large differences in efficiency of twin-scale propagation among individuals native to Dongyin, regeneration percentage ranged between 63 to 98 %. Among these individuals, Lycoris × rosea ‘Ly008’ has the highest regeneration percentage (97.7%), and Lycoris sprengeri ‘Ly002’ has the second highest percentage (96.1%).
Seeds of Lycoris sprengeri mature during September to November. The average length of seeds about 7 mm, width about 7.3 mm, hundred-grain weight about 17 g, lustrous black, and ball shape in appearance are the characters of Lycoris sprengeri seed. Lycoris sprengeri is hypogeal germination. After radicle breaking out the seed coat, the coleoptile extends into the soil, and then the end of enlarged coleoptile forms bulblet. When bulblet matures, the radicle will atrophy and be replaced by fibrous roots. The first foliage will appear during Febuary to March after the cold winter in the next year or the year after the next. Optimum temperature for germination is 20 to 25℃, and bulblet grows well. Lycoris sprengeri’s seeds with priming treatment by potassium nitrate and PEG8000 can accelerate development and improve the germination percentage. Seeds with priming treatment at 25 ℃ in -1.0 Mpa PEG8000 solution for 5 days had the highest germination percentage of 97.8%.
Bulb scales from native habitat of Lycoris sprengeri were cultured year-round in order to find the best time for excision. Scales cultured in June gave the highest percentage of contamination. Meanwhile, scales cultured in March and September have the least contamination; they have the hightest percentage of explants producing adventitious buds, and their inner scales gave higher percentage of explants producing adventitious buds than outer scales. The cultured outer scales gave more number of explants producing adventitious buds than inner scales. The highest number of explants producing adventitious buds is 3.9. The cultured outer scales gave the longest length of adventitious buds which is 17 mm. Hot water treatment can effectively reduce the contamination percentage, but with prolonged time of treatment, the browning percentage of outer scales often increase. The bulblets from cultured scales gave high survival percentage to 100% after subculture and acclimation. And secondary explants, such as stem plate and bulblet section, can be effectively used for proliferation culture.
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