|關鍵字： 鳳梨；催花；乙烯；電石；葉圓片；硫酸銅；ACC；pineapple；force flowering；ethylene；calcium carbide；leaf disc；CuSO4；ACC
|摘要： 台灣鳳梨生產上常使用電石水催花，但電石水之催花效果不穩定，因此本實驗欲釐清電石水中成分對催花效果之影響，以及找尋可能取代電石水之藥劑。因此將鳳梨成熟株以電石水、電石氣(乙炔氣)、乙烯、無電石氣之電石水處理，或先處理1-MCP後再處理電石氣，結果顯示電石水、電石氣及乙烯處理，皆可誘導開花，而植株經1-MCP或無電石氣之電石水處理後則未開花，顯示電石水中之乙炔是主要刺激開花之物質。催花後50天，大部分植株即將進入小花開放階段，開花株綠色部分之氮及鈣含量較未開花株多，而全可溶性糖/全氮比值則較未開花株小，澱粉及氮/鈣比則與未開花株無顯著差異。 以電石水上清液、無電石氣之電石水或電石水誘導葉圓片產生乙烯，結果顯示電石水上清液誘導乙烯產生量較電石水處理多，但無電石氣之電石水處理後乙烯產生量減少，顯示電石水中的沉澱物會影響乙炔誘導乙烯生成。 鳳梨D葉中白綠及淡綠色產生的乙烯量最多，而以此部分之葉圓片作化學藥劑及荷爾蒙測試誘發乙烯產生之能力。磷酸二氫鉀(KH2PO4)、0.1mM Kinetin、0.5 ppm IBA、磷酸一氫鉀(K2HPO4)、氯化鈣(CaCl2)及硝酸鈣(Ca(NO3)2)皆無法誘導乙烯產生。然而，硫酸銅(CuSO4)處理後明顯刺激葉圓片產生乙烯，於25℃下0.5mM CuSO4有最多乙烯產生。但短暫浸泡CuSO4溶液10分鐘可誘導更多乙烯產生，如6-12小時之乙烯釋放率約為25℃下0.5mM CuSO4持續培養之3.5倍。CuSO4能使乙烯產生主要是由於刺激ACC合成。結果也顯示益收處理葉圓片後可產生大量乙烯。 硫酸銅能明顯誘導乙烯產生，因此，實際施用於植株調查其催花能力。鳳梨植株以電石水、油脂包覆之電石粒、不同濃度(0.5、1及2mM)之氯化銅或硫酸銅以及益收進行催花處理，其中益收處理較有效，開花率為85%，電石水與油脂包覆電石粒開花率皆為21%，其餘處理皆未開花。葉片白色部分之氮含量隨催花後時間增加由1.45%下降至0.51%，而綠色部分則約維持於1-1.2%之間，但益收處理之綠色部分於催花後氮明顯上升。益收處理之葉片綠色部分可溶性糖含量於開花前較其他處理低，而澱粉含量則無明顯差異。 硫酸銅能誘導葉圓片大量乙烯產生，但在完整植株中卻非常少。催花失敗之原因可能是產生之乙烯量不足以誘導開花，或葉表面有蠟質結構阻擋其進入葉肉細胞，而導致無法開花。In Taiwan, the force flower treatment of pineapple usually used calcium carbide (CaC2) solution, but it was unstable. For this reason, the object of this study was to clear the ingredients in CaC2 solution which affected flower induction and found chemicals that may be replaced CaC2 solution. Mature pineapple plants were treated with CaC2 solution, CaC2 gas (acetylene gas), ethylene gas, CaC2 solution without acetylene gas, or first treated with 1-MCP then CaC2 gas. Results showed that CaC2 solution, acetylene gas, and ethylene gas could induce plants to flower. Plants treated with 1-MCP or CaC2 solution without acetylene gas did not flower, suggesting that acetylene gas was the main ingredient in CaC2 solution which stimulated flowering. Most of the plants bloomed at 50 days after forced flowering. The nitrogen and calcium content in the green part of the leaves of flowering plants was higher than in non-flowering plants. And the ratios of total soluble sugar to total nitrogen in flowering plants were lower than in non-flowering plants. There were no significant differences in starch content and nitrogen/ calcium ratios between flowering and non-flowering plants. Ethylene production in leaf discs was induced by treatments with CaC2 supernatant liquid, CaC2 solution without acetylene gas, or CaC2 solution on leaf discs. Results showed that CaC2 supernatant liquid could induce more ethylene production than CaC2 solution did, but ethylene production was decrease after treatment with CaC2 solution without acetylene gas, suggested that the precipitates in the CaC2 solution could affect acetylene-induced ethylene production. The white-green and light green sections of D leaf in pineapple plants were found to produce the most ethylene. Leaf discs from these sections were examined for the ability to further produce ethylene by using chemicals and hormones. KH2PO4, 0.1mM kinetin, 0.5ppm IBA, K2HPO4, CaCl2, and Ca(NO3)2 could not induce leaf discs to produce more ethylene. However, there was obvious ethylene production by leaf discs after treatment with CuSO4, the highest ethylene production rate being from the concentration of 0.5mM CuSO4 at 25℃. But there was even more ethylene production when leaf discs were dipped in 5mM CuSO4 aqueous solution for 10 minutes. For example, the ethylene production rate for 5mM CuSO4 at 6-12 hr was 3.5 times higher than discs incubated in 0.5mM CuSO4. CuSO4 ability to produce ethylene may be stimulated by ACC synthase activity. Results also showed the leaf discs produced a large amount of ethylene after treatment with ethephon. Leaf discs could produce ethylene after CuSO4 treatment, so CuSO4 applying to the plants then evaluated the capability of flower induction. Pineapple plants were treated with CaC2 solution, oil-coated CaC2, different concentrations of CaCl2 or CuSO4 (0.5, 1, and 2mM), and ethephon for forcing flowers. Among them, ethephon treatment was more efficienct: 85% in flowering rate. The flowering rate of CaC2 solution and oil-coated CaC2 was 21%. Other treatments did not force flowering. The nitrogen content in the white part of D leaf was decreased with the forced flowering time, from 1.45 to 0.51%; and the green part of the leaf was maintained between 1 to 1.2%; but the nitrogen content in the green part of the leaf was significantly increased after ethephon forced flowering treatment. The total soluble sugar in the green part of the leaf before flowering by ethephon treatment was lower than other treatments, but starch had no significant difference between treatments. CuSO4 could induce considerable ethylene production from leaf discs but very little from whole plants. The reason for failure of flower induction may be due to the fact that the quantity of ethylene production was too low to induce flowering, or there was wax on the leaf surfaces which obstructed cupric ions from entering the leaf tissues and resulted in flowering failure.