| Summary: | 碩士 === 國立臺灣大學 === 園藝學研究所 === 99 === 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.
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