根区缓冲降温处理对葡萄叶片冻害的影响

为探索根区降温条件对葡萄(Vitis vinifera)叶片冻害的影响,以1年生美乐葡萄(V.vinifera cv.‘Merlot’)幼苗为试材,设置根区正常降温和缓冲降温2种降温条件,人工模拟霜冻,分析了叶片冻害指数和叶片的荧光参数。结果表明,根区正常降温会导致根系受冻,同时叶片发生严重的冻害,冻害指数达74.36%;根区缓冲降温使根区温度保持在0°C以上,叶片冻害指数降低53.29%,仅有21.07%的叶片遭受了冻害。根区缓冲降温处理能有效提高叶片霜冻恢复过程中光化学淬灭系数(qP)和天线色素转化效率(F_v~'/F_m~'),加快PSII光合电子传递量子效率(Φ_(PSII))的恢复,提高热耗散能力(NPQ),减轻霜冻后的光抑制(F_v/F_m),有利于叶片霜冻后的恢复。

Effects of Buffered Cooling in Root Zone on Frost Injury in Grape Leaf

To study the effects of cooling conditions in the root zone on frost injury in grapevine leaves, we used 1-year-old Merlot grapevine (Vitis vinifera) seedlings. The root zone was cooled regularly or buffered. All seedlings were treated in the simulated frost condition, then the frost index in leaves was calculated, and the chlorophyll fluorescence parameters were analyzed to reflect the change of PSII activity. Root temperature cooled regularly conferred severe frost damage in leaves, with a frost index of 74.36%. Buffered cooling alleviated frost injury to 53.29%, with a frost index of only 21.07%. Buffered cooling in the root zone improved qP and F_v?/F_m? in leaves during the recovery period, sped up the recovery of photochemical activity in PSII (Φ_PSII), improved the ability of heat dissipation (NPQ), and relieved photo- inhibition. Buffered cooling in the root zone was conducive for leaves to recover after frost.