香蕉之子房培養

Abstract

以香蕉(Musa Cavendishii Lamb)子房及子房切段爲培植體，於組織培養環境下，探討培植體大小及培養基組成鹽類，氮源，碳素及生長調節物質等對子房培養發育的影響。 試驗材料採用長度4~8cm，重量2~5gm的子房，因其對處理有明顯反應，易觀察及比較。 香蕉子房在液態培養基中生長較在固態培養基中爲佳，鮮重，乾重、長度之增加亦較多。 子房在MS大量鹽類，全量、二分之一、四分之一、八分之一四種用量中，外觀並無不同，長度及乾重之增加經鄧肯氏多種變域測驗法分析無顯著之差異，但全量MS對子房鮮重之增加較其他各組爲顯著。 在所試蔗糖、葡萄糖及果糖三種糖類中，以蔗糖較適合子房之生長，葡萄糖及果糖都會引起子房基部不同程度的褐化。6%之蔗糖爲試驗結果中最佳之濃度。 所試五種氮源，KNO3+(NH4)2SO4，KNO3，(NH4)2SO4，Urea, glutamine中，NH(上標 +)4-N引起子房基部褐化的程度較NO(上標 -)3-N所引起者爲輕，兩者合用較單獨使用之效果爲佳。 生長調節物質中，phenoxy acids類auxin(2,4-D, 2,4,5-T, 0-CPA, P-CPA)，對香蕉子房長度之增加皆有明顯的促進作用，但濃度超過1mg/ℓ，子房生長過速彎曲呈S型，甚至頂部褐化。BA與GA3對香蕉子房之正常生長甚有助益，有助於果肉之生長。 試管中培養之香蕉果肉有澱粉堆積，果皮有單寧細胞存在，培養16~20週後，會自發轉黃而成熟，成熟時果重約15~30公克，約爲自然成長者的七分之一。 Banana (Musa Cavendishii Lamb) ovaries and ovary segments were cultured and its responses in growth and development were followed. The experimental factors included: (1) size of explant, (2) form of media, (3) concentration of macro-element salts, (4) source of carbohydrate, (5) concentration of sucrose and (6) concentrations and combinations of growth regulators. The results are as follows: Ovaries, 4-8 cm in length and 2-5 gm in weight, collected from the 3rd to 8th hands of emering inflorescence responed to culture much better in growth and development. Ovaries of smaller or larger sizes showed little response to culture. Growth of ovary expressed in increase in fresh weight, dry weight and length were higher in liguid than on agar media. There were no difference in external appearance and in length and weight of ovaries cnltured in media containing macro-elements of MS salt (1962) in 1, 1/2, 1/4, and 1/8 strength. But the increase in fresh weight of ovaries cultured in full strength of MS salts was significantly higher than in other treatments. Sucrose gave much better growth than glucose or fructose. Growth of ovaries in 6% sucrose was better than in 3% or 9%. NH4(superscript +)-N was more suitable for culture of banana ovaries than NO3(superscript -)-N. With the same concentration of nitrogen, NH(superscript +)4-N and NO(superscript -)3-N in combination gave better growth than either one used alone. In comparison with the indole auxins, phenoxy acid auxins (2, 4-D, 2, 4, 5-T, O-CPA, P-CPA) in concentrations of 0.01, 0.1, 1, 5, 10 mg/l showed promotive effects on increase in length of ovaries. With concentrations higher than 1 mg/l, ovaries became curvature of S shape possibly due to unequal growth in different portion. BA and GA3 in concentrations of 1, 5, 10 mg/l gave normal growth of ovary filled with pulp. Starch grains in pulp and tannin cells in peel of cultured ovary were detected. Cultured ovaries became yellow and showed the sign of ripening after 16 to 20 weeks in culture. The weight of ripened ovaries ranged from 15 to 30 gms, about one-seventh of the weight of a normal fruit.