蘇鐵蕨之穴盤栽培

Plug Production of Brainea insignis (Hook.) J.Sm.

高碧霜(Bi-Shuang Gao)

指導教授 ： 楊雯如

共同指導教授 ： 葉德銘(Der-Ming Yeh)

國立臺灣大學/生物資源暨農學院/園藝學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.02687

摘要

台灣有高達六百多種蕨類，其中有一些是原生種；然有關其園藝利用潛力的研究仍非常有限。其中烏毛蕨科蘇鐵蕨屬蘇鐵蕨 [Brainea insignis (Hook.) J.Sm.]為具有園藝觀賞價值的原生種，其園藝性狀為直立莖、一回羽狀複葉叢生於莖頂、新葉萌發時呈紅色、高可達1公尺的樹蕨。
　　在7.5、15、22.5或30顆孢子/ cm2孢子撒播密度試驗範圍中，孢子撒播密度不影響蘇鐵蕨的孢子發芽率，但影響孢子體形成的數量。平均撒播7.5、15、22.5或30顆孢子/ cm2，孢子發芽率無顯著差異，在61%-76%之間，15顆孢子/ cm2以上，而無配子體之穴格比率才會低於1%；其後孢子體密度分別為 0.6、2.5、7.9及7.5棵孢子體/ cm2。孢子撒播密度亦會影響配子體性別，低密度下雌配子體數偏高，高密度下雄配子體數偏高。每平方公分平均撒播3、6、11、19、27或55顆孢子，在3顆孢子/ cm2下，64%配子體為雌性；反之，在55顆孢子/ cm2則61%配子體為雄性。由孢子體的葉片數及葉片長來看，以處理15顆孢子/ cm2為建議播種密度，其生長量最高，平均具3片葉且葉片長達1.78 cm。
　　本研究亦探討養液需求對蘇鐵蕨孢子體發育的影響。以0%、25%、50%或100%強生氏養液培養者，其無孢子體之穴格比率分別為59.9%, 56.6%, 29.3%和98.2%。50%強生氏養液的之穴格，具最高孢子體數量(3.4棵孢子體)、最多孢子體葉片及最高鮮重(101.8 mg)、其葉片葉長最長且有較高SPAD 值。
蘇鐵蕨的孢子發芽需要光，在黑暗處理下發芽率僅2.5%，在20、31、38、47 μmol•m-2•s-1 PPF光照下，發芽率皆在72%-83%之間。隨著光度的增加，雄配子體比例下降的趨勢。光照47 μmol•m-2•s-1 PPF者最早長出孢子體，且孢子體密度最高(6.4棵孢子體/穴格)，穴格整齊度高，達93%。小苗具三片葉時移植，移植前在180 μmol•m-2•s-1光度下馴化2周可減少死亡率且促進小苗之健化。幼孢子體（具6至10片葉）在60 μmol•m-2•s-1下生長勢較90、120、150及200 μmol•m-2•s-1之光度強。

關鍵字

繁殖, 烏毛蕨科, 孢子撒播密度, 孢子撒播光度

並列摘要

In Taiwan, there are more than 600 species of pteridophyte and some of them are native species; however, the evaluation of their potential in horticulture was very limited. Among the native species, Brainea insignis (Hook.) J.Sm. of Blechnaceae is of horticultural potential. The pteridophyte is often higher than 1 m and characterized with an erect stem and clustered single pinnate compound leaves. Moreover, the reddish new fond enriched its ornamental value.
　　Among the 4 sowing densities, 7.5, 15, 22.5, 30 spores/cm2, sporophyte formation and plug uniformity of Brainea insignis was affected by spore sowing density. The spore germination rates, 61%-76%, were not significant different among the sowing densities. The ratio of null plug (plug with no gametophyte) was less than 1% when the sowing density was higher than 15 spores/cm2. Besides, the sporophyte density was 0.6, 2.5, 7.9, and 7.5 sporophytes/cm2, respectively. Sowing density also affected gametophyte gender expression; the gender tended to develop into female under lower density and to develop into male under higher density. The ratio of female gametophyte reached 64% under 3 spores/cm2, and the ratio of male gametophyte tended to be 61% under 55 spores/cm2. In consideration of the sporophyte biomass, 15 spores/cm2 was suggested for the highest growth, 3 leaves per sporophyte and the leaf length was 1.78cm in average.
　　Nutrient requirement for sporophyte development of Brainea insignis was also investigated in this study. The ratios of plugs with no sporophyte were 59.9%, 56.6%, 29.3% and 98.2% for sowing and growing under 0%, 25%, 50%, and 100% Johnsons’ solution, respectively. Sporophyte/ plug, number of leaves/plug, fresh weight/ plug were highest when 50% Johnsons’ solution was supplied. Besides, the leaves under such nutrient condition were largest and with highest SPAD value.
　　Irradiance was acquired for spore germination of B.insignis. The germination rate was 2.5% under dark, but reached 72%-83% under 20, 31, 38 and 47 μmol•m-2•s-1 PPF. Male gametophyte rate decreased as light intensity increased. Under 47 μmol•m-2•s-1 PPF, sporophytes appeared earliest and the number of sporophytes per plug were the highest (6.4 sporophytes/plug). Besides, the sporophyte uniformity reached 93%. Two weeks of acclimation under 180 μmol•m-2•s-1 PPF was suggested for 3-leaves sporophyte before transplanting. The growth of young sporophyte (with 6-10 fronds) was much vigorous under 60 μmol•m-2•s-1 than under 90, 120, 150 and 200 μmol•m-2•s-1.

並列關鍵字

propagation, Blechnaceae, spore sowing density, spore sowing light intensity

參考文獻

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