甘藷葉之耐低溫篩選及低溫對其生理之影響

Screen of Sweet Potato (Ipomoea batatas L.) Leaves for Chilling Tolerance and the Effect of Chilling on Physiology

低溫逆境會造成葉用甘藷於品質和產量上的嚴重傷害，葉片外觀出現萎凋、水浸狀、黃化和壞疽。本試驗之目的為篩選耐低溫品種。觀察甘藷葉五品種於黑暗6下0、3、5、7、9和15小時與回溫24和48小時期間之葉片寒害指數與復原指數，總寒害指數於‘日本種’為7.31、‘大葉種’為8.13和‘台農71號’為6.75，‘黃葉種’為14.44和‘裂葉種’為12.22，總復原指數‘日本種’為5.47、‘大葉種’為3.00和‘台農71號’為5.10，，‘黃葉種’為10.15和‘裂葉種’為7.49綜合寒害指數、復原指數和葉綠素螢光值較耐寒品種為‘日本種’、‘大葉種’和‘台農71號較不耐寒品種為‘黃葉種’和‘裂葉種’。‘台農71號’處理15小時後回溫48小時之Fv／Fm顯著增加，於6下9小時和15小時之SOD活性皆顯著上升。

Chilling stress causes great damages to the quality and yield of sweet potato leaves. The injured leaves would appear wilted, water-soaked and yellow, with patches of necrosis. The aim of this experiment was to select chilling tolerant cultivars of sweet potatoes. Five sweet potato cultivars were observed at 6 in the dark for 0, 3, 5, 7, 9 and 15 h, and then subsequently kept at 25 for 24 and 48 h for recover. The total chilling injury indices of ‘Japanese’, ‘Big leaves’, ‘Tainung 71’, ‘Yellow leaves’ and ‘Cracked leaves’ were 7.31, 8.13, 6.75, 14.44 and 12.22, respectively, while their total recovery indices were 5.47, 3.00, 5.10, 10.15, and 7.49, respectively. The results demonstrated that ‘Japanese’, ‘Big leaves’ and ‘Tainung 71’ leaves exhibited more chilling tolerance, compared to ‘Yellow leaves’ and ‘Cracked leaves’. ‘Tainung 71’ maintained at 6 for 15 hours and then recover for 48 hours (R 48 hr) showed significant increase of Fv/Fm, and the plants kept at 6 for 9 and 15 hours had higher SOD activity.