| الوصف: |
溫度是影響芒果生長與發育的重要的環境因子之一。研究探討，十個芒果品種葉片在溫度逆境(包含高溫與低溫)下對葉綠素螢光、電解質滲漏率、乙烯生成量以及呼吸率的影響。在高溫逆境部分，芒果葉片於黑暗生長箱內分別以30、35、40、45、50、55℃熱處理24個小時。結果顯示，葉綠素螢光有隨著處理溫度與時間的上升而下降之趨勢。在50與55℃時，電解質滲漏率在溫度上升或處理時間拉長時會有顯著的增加，乙烯的生成量與呼吸率在溫度上升時都有增加的現象。另外，當芒果葉片對溫度的反應到達高峰之後，乙烯生成量與呼吸率會下降。 低溫處理把葉片置於7個溫度(25、12、9、5、3、1、-3℃)，調查其葉綠素螢光之改變。然而僅取4個溫度(25、9、1、-3℃)測定電解質滲透率、乙烯生成量以及呼吸作用的改變。結果顯示，葉綠素螢光會隨著低溫處理時間增長而有下降的趨勢，而電解質滲漏率則會隨著溫度下降以及時間增長而上升。在低溫逆境下乙烯生成量與呼吸率的改變則不明顯。 上述四種用檢測芒果不同品種葉片在高溫以及低溫下其耐受性的方法中，以葉綠素螢光法最有效率。以葉綠素螢光作為指標，可選出 ‘M-18’、 ‘Yai Klam’、 ‘愛文’、 ‘Sensation’ 為對熱具有耐受性之品種。對低溫有耐受性之品種則為： ‘Chin Hwang’、 ‘愛文’、 ‘FP-1’、 ‘Sensation’與 ‘海頓’。 ; Temperature is one of the most important environmental factors, that affects growth and development of all liking creatures, including mango. In this study, the leaves of ten mango cultivars were exposed to temperature stresses (high and low temperature) and the changes in chlorophyll fluorescence, electrolyte leakage, ethylene production, and respiration were determined. For high temperature stress, mango leaves were treated in a dark-incubator at 30, 35, 40, 45, 50 and 55oC for 96h. Results showed that, chlorophyll fluorescence tended to decrease as temperature and duration of treatment increased. At 50 and 55oC, electrolyte leakage showed marked increase with the increase in temperature and/or duration of treatment. Ethylene production and respiration also increased with temperature rise. But responses to heat shock in mango leaves are decreased ethylene production and respiration rate. For low temperature stress, leaves were exposed to seven temperatures (25, 12, 9, 5, 3, 1 and -3oC) and the changes in chlorophyll fluorescence were determined. However only four temperatures (25, 9, 1 and -3oC) were used to determine the changes in electrolyte leakage, ethylene production and respiration. Results showed that chlorophyll fluorescence tended to decrease at prolonged exposure to low temperatures, while electrolyte leakage increased as temperature decreased and duration increased. The changes under low temperature stress in ethylene ... |