甘藍對高溫淹水之生理反應

Abstract

甘藍(Brassica oleracea L. var. capitata L.) 為世界性重要蔬菜，臺灣2000~2009年甘藍栽培面積平均8,642公頃，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，甘藍25個品種苗株經過淹水兩天後，’228’、’早秋’及’BB113’之葉綠素螢光Fv/Fm值皆未下降。2009年夏季分別於雲林縣二崙鄉及臺南市新化區臺南區農業改良場田間進行25及24個品種淹水試驗，根據產量選出’青翠’、’No.525’、’228’、’夏峰一號’、’大蕊’、’早秋’、’初秋’、’臺南一號’及’臺南二號’共9個品種，在2010年夏季於臺南場再淹水2天後，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35/30oC不淹水、35/30oC淹水、25/20oC不淹水及25/20oC淹水處理48小時，‘228’經35/30oC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35/30oC淹水下具有較佳之穩定性；但其臘質含量於淹水48 小時顯著減少。‘228’與‘大蕊’於35/30oC淹水及不淹水48小時，脯胺酸含量皆顯著增加，25/20oC淹水48小時則僅‘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35/30oC不淹水、35/30oC淹水及25/20oC淹水處理48小時皆比’大蕊’高。‘228’與‘大蕊’25天苗株予以40/35oC不淹水、40/35oC淹水、25/20oC淹水及25/20oC不淹水處理48小時後，’大蕊’之氣孔導度於三種逆境下升高程度皆較‘228’大。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 average planting area of cabbage in Taiwan was 8,642 ha from 2000 to 2009. 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 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. Chlorophyll fluorescence Fv/Fm values of ’228’,’ Tazu Chiou’ and ’BB113’ did not decrease significantly. Twenty-five and 24 cabbage cultivars were treated with waterlogging for two days in the field at Yunlin and Tainan in 2009 summer. According to the yield, ’Ching Tsuei’, ’No.525’, ’228’, ’Shia Feng No.1’, ’Fuyudori’, ’Tazu Chiou’, ’ Chu Chiou’, ’ Tai Nan No.1’, and ’ Tai Nan No.2’ were selected to conduct waterlogging trial at Tainan in 2010 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 sown in growth chamber. Twenty-five days seedlings were treated with 35/30oC, 35/30oC with waterlogging, 25/20oC, and 25/20oC with waterlogging, separately. Membrane injury index (MII) and relative water content (RWC) of ‘228’ treated with 35/30oC and waterlogging did not change significantly. Proline contents of 2 cultivars treated with 35/30oC with and without waterlogging for 48 hr increased significantly. But in the treatment of 25/20oC and waterlogging for 48 hr, only ‘228’ increased proline significantly. For treatments of 35/30oC with and without waterlogging, and 25/20oC with waterlogging, the activities of antioxidtive enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) increased more in ‘228’. Twenty-five day seedlings of 2 cultivars were treated with 40/35oC, 40/35oC with waterlogging, 25/20oC, and 25/20oC with waterlogging, separately. Stomatal conductance of ’Fuyudori’ significantly increased more than ’228’ in the treatments of 35/30oC with and without waterlogging, and 25/20oC with waterlogging. Therefore, 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.