粗肋草花序培養、不定芽再生繁殖及瓶內馴化

Abstract

花序培養具有容易表面消毒，減少內生菌汙染，且不會犧牲母株等優點。本研究以粗肋草佛焰苞片未展開之花序為培植體，探討培植體選擇及培養基內主要鹽類濃度、蔗糖、葡萄糖、及植物生長調節劑對其誘導癒傷組織之影響。以誘導之粒狀癒傷組織為培植體，研究植物生長調節劑對其再分化為不定芽之影響。並探討培養基內碳水化合物、NAA及細胞分裂素對其誘導叢生芽之影響。另調整瓶內蔗糖濃度及瓶內光度，調查其出瓶後之生長速率，葉片光合作用能力及葉片解剖，期能找出合適的培養基蔗糖濃度及瓶內光度，以提高出瓶後之環境適應性和植株生長速率。 粗肋草雄花部位微體繁殖，應選擇較幼嫩的基部雄花部位作為培植體，且在培養時培植體以全圓薄片不進行分切，正放於培養基中，其誘導粒狀癒傷組織之效果較佳。雄花部位微體繁殖以1/2MS培養基添加2%蔗糖處理較佳。粗肋草 ‘Silver Bay’以培養基內添加15 µM TDZ與10 µM Dicamba誘導粒狀癒傷組織效果較佳，粗肋草 ‘White Tip’則以10 µM TDZ與10 µM Dicamba誘導粒狀癒傷組織較多。兩品種雌花部位粒狀癒傷組織誘導率均較雄花部位高。由十三種粗肋草雜交品系及品種試驗結果可知，雄花部位培植體誘導粒狀癒傷組織大多需要Dicamba的參與，雌花部位培植體則需要TDZ的參與。粒狀癒傷組織以添加5 - 10 µM BA處理者，其不定芽誘導率較高，有較多的不定芽且芽較長。 以花序誘導之不定芽作為培植體，粗肋草 ‘白馬’以全量MS培養基添加2%蔗糖處理誘導叢生芽較佳，組合植物生長調節劑10 µM NAA與10 µM CPPU有利於增加粗肋草 ‘白馬’之叢生芽誘導。提高CPPU濃度由0增加至10 µM，誘導芽體數亦增加；但高濃度CPPU (15、20 µM)會降低其增殖倍率。高濃度15或20 µM 之TDZ處理會使芽體叢生、葉片捲曲且無法正常伸長。 粗肋草 ‘白馬’組培苗在含2%、4%及6%蔗糖之半固體培養基培養90天後取其大小一致之小苗，調查出瓶馴化期間之光合作用及生長狀況。白馬粗肋草於瓶苗培養時期以2%蔗糖處理者根數較少根長較短，但出瓶後60天之生長量較4%及6%蔗糖處理者佳。2%蔗糖處理者瓶內形成葉片，在馴化初期Fv/Fm值下降幅度較少且回復較快。2%、4%及6%蔗糖濃度處理之蒸散作用、氣孔導度及光合作用隨馴化時間增長呈上升趨勢，以2%蔗糖處理較高。粗肋草 ‘白馬’於2%蔗糖處理瓶內形成葉片之光合作用能力較4%及6%蔗糖濃度處理者高。 粗肋草 ‘白馬’組織培養苗於瓶內給予25、50、100 µmol•m-2•s-1光度馴化90天，調查出瓶馴化期間光合作用及生長狀況。粗肋草 ‘白馬’於出瓶時以25 µmol•m-2•s-1光度處理者生長較佳，但出瓶後100天之生長量以100 µmol•m-2•s-1處理者較佳。100 µmol•m-2•s-1光度處理於出瓶時之葉綠素計讀值較低，但於馴化第32天時較其他處理高。蒸散作用、氣孔導度及光合作用隨馴化時間增長呈上升趨勢，以100 µmol•m-2•s-1光度處理較高。

Using inflorescences as explants would offer great promise to Aglaonema plants, which could be mass-propagated from a single inflorescence without significant damage to the mother plants. The objectives of this study were 1) to determine the effects of explant size, and concentrations of macro-element, carbohydrate, and plant growth regulators in the medium on callus induction of Aglaonema inflorescences, 2) to determine the effects of macro-element, NAA, and cytokinin concentrations on shoot multiplication from granular callus, and 3) to measure the photosynthesis and growth of plants which had been cultured under different in vitro sucrose concentrations and photosynthetic photon flux. Using young, basal portion of male flowers (4 to 5 cm) as explants and normal polar orientation resulted in maximum granular callus. Maxium granular callus of male flowers were achieved in half strength MS medium containing 2 % sucrose. Medium supplemented with 15 µM TDZ and 10 µM Dicamba resulted in maxium granular callus of male flowers in Aglaonema ‘Silver Bay’, and with 10 µM TDZ and 10 µM Dicamba in Aglaonema ‘White Tip’. More granular callus induction was obtained from female flowers than male flowers in both cultivars. Dicamba and TDZ were required for granular callus in male and female flowers, respectively in 13 cultivars or hybrid lines treated. Maximum shoot number and longest shoot length were recorded when granular callus was treated with 5 to 10 µM BA. Full MS medium containing 2% sucrose, 10 µM NAA and 10 µM CPPU resulted in maximum shoot number of Aglaonema ‘White Tip’. Shoot number increased with increasing CPPU concentration from 0 to 10 µM CPPU, but shoot number decreased with 15 or 20 µM CPPU. Medium with 15 or 20 µM TDZ resulted in rosetted clusters with small and curved leaves. In vitro bud clusters of Aglaonema ‘White Tip’ were obtained in medium supplemented with 2%, 4% or 6% sucrose concentrations for 90 days. Plants cultured with 2% sucrose in vitro reduced shoot number and root length at transfer, but had greater growth than those obtained from 4% or 6% sucrose after 60 days of transfer. Leaf Fv/Fm value decreased slowly in the early period after transfer and increased rapidly in plants obtained from the 2% sucrose treatment. The net photosynthesis rate, stomatal conductance and transpiration rate of in vitro-form leaves increased during acclimatization in all plants. Howerer, plants obtained from the 2% sucrose treatment had substantial higher photosynthetic rate than plants from 4% or 6% sucrose. Plants of ‘White Tip’ were acclimatized in vitro for 90 days under fluorescent tubes providing PPF of 25, 50 or 100 µmol•m-2•s-1. Plants under 25 µmol•m-2•s-1 in vitro had greater growth at transfer, while those under 100 µmol•m-2•s-1 grew better after 100 days of transplant, as compared with other PPF treatments. Plants under 100 µmol•m-2•s-1 had lower SPAD-502 reading at transfer, however, the SPAD-502 reading increased rapidly and higher than other PPF treatments. In vitro-form leaves of plants under 100 µmol•m-2•s-1 had higher net photosynthesis rate, stomatal conductance and transpiration rate during acclimatization than those of plants under 25 or 50 µmol•m-2•s-1.