甘藍對高溫淹水之生理反應

Physiological Response of Cabbage (Brassica oleracea L. var. capitata) to High Temperature and Waterlogging

甘藍（Brassica oleracea L. var. capitata L.）為世界性重要蔬菜，臺灣2013年甘藍栽培面積7570ha，但夏秋之間經常受颱風或豪雨侵襲，造成供需失衡。本研究依據夏季淹水產量試驗，選出耐及不耐高溫淹水之品種，探討其苗株在高溫淹水逆境下之生理差異。2009年夏季淹水產量結果顯示結球率、單位面積產量、單株葉球重及生長級數總和均以‘No.525’及‘228’最高，而‘大蕊’之單位面積產量、單株葉球重及生長級數總和皆為最低，故選擇經濟栽培品種228為耐高溫淹水品種，‘大蕊’為不耐高溫淹水品種，進行苗株高溫淹水生理試驗。兩品種於生長箱中育苗，25天苗予以35/30℃不淹水、35/30℃淹水、25/20℃不淹水及25/20℃淹水處理48h，‘228’經35/30℃淹水處理後，膜傷害指數（membrane injury index，MII）與相對水分含量（relative water content，RWC）皆無顯著變化，其原生質膜與水分吸收於35/30℃淹水下具有較佳之穩定性；但其臘質含量於淹水48h顯著減少。‘228’與‘大蕊’於35/30℃淹水及不淹水48h，脯胺酸含量皆顯著增加，25/20℃淹水48h則僅‘228’脯胺酸含量顯著升高。‘228’之超氧岐化酶（superoxide dismutase, SOD）、抗壞血酸過氧化酶（ascorbate peroxidase, APX）、過氧化氫酶（catalase, CAT）與穀胱甘肽還原酶（glutathione reductase, GR）活性於35/30℃不淹水、35/30℃淹水及25/20℃淹水處理48h皆比‘大蕊’高。故甘藍‘228’與‘大蕊’25天苗株在高溫淹水逆境下MII、氣孔導度、RWC、SOD、APX及GR活性之優劣表現與夏季淹水產量之高低互相對應，這些參數或可作為甘藍高溫淹水耐受性之篩選指標。 Cabbage (Brassica oleracea L. var. capitata L.) is a worldwide important vegetable. The planting area of cabbage in Taiwan was 7,570ha in 2013. But in the summer and autumn, typhoons often cause imbalance of supply and demand of cabbage. In this research, high temperature and waterlogging-tolerant and-sensitive cultivars were selected by yield during summer to study their physiological differences at seedling stage under high temperature and waterlogging stresses. Seedlings of 25 cabbage cultivars were treated with waterlogging for two days in 2009 summer. 'No.525' and '228' exhibited the highest heading percentages, yield per unit area and sum of growth score. 'Fuyudori' showed the lowest yield per unit area, weight of leaf head and sum of growth score. High temperature and waterlogging tolerant cultivar '228' and sensitive cultivar 'Fuyudori' were used as experimental materials of seedling experiment. Seeds were germinated in growth chamber. Twenty-five days seedlings were treated with 35/30℃, 35/30℃ with waterlogging, 25/20℃, and 25/20℃ with waterlogging, separately. Membrane injury index (MII) and relative water content (RWC) of '228' treated with 35/30℃ and waterlogging did not change significantly. Proline contents of both cultivars treated with 35/30℃ with and without waterlogging for 48 h increased significantly. But in the treatment of 25/20℃ and waterlogging for 48 h, proline only increased in '228' significantly. For treatments of 35/30℃ with and without waterlogging, and 25/20℃ with waterlogging, the activities of antioxidtive enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) were all higher in '228'. Finally, the expressions on MII, RWC, stomatal conductance, and SOD, GR and APX activities of cabbage '228' and 'Fuyudori' seedlings under high temperature and waterlogging were similar to yield in waterlogging trials in summer. These parameters might be used as screening indicators for high temperature and waterlogging tolerance of cabbage.