不同光质夜间补光对番茄幼苗耐冷性的影响

Effect of Nighttime Exposure to Light from Color Lamps on Cold Tolerance of Tomato Seedlings

【目的】探讨不同光质夜间补光对番茄幼苗耐冷性的影响,为提高番茄幼苗耐冷性提供理论和实践依据。【方法】以倍盈番茄为试验材料,采用光质分别为白光(W)、红光(R)、蓝光(B)和红蓝组合光配比(2R/8B、5R/5B、8R/2B)等6个组合进行夜间补光处理,20 d后各处理番茄幼苗置于亚低温(10℃/5℃)下胁迫,以未补光所培育番茄幼苗为对照。【结果】与对照相比,各补光处理所培育的番茄幼苗在亚低温处理期间叶片中的电解质渗透率和丙二醛(MDA)含量上升幅度均显著低于对照,红蓝复合光(2R/8B、5R/5B、8R/2B)在亚低温胁迫期间叶片一直保持着较高的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性,在亚低温胁迫6 d时以红蓝复合8R/2B活性上升幅度最高,分别达到399.49%、129.01%和135.74%,显著高于对照。【结论】夜间补光处理均可提高番茄幼苗的耐冷性,其中以红蓝复合8R/2B补光处理的幼苗的抗低温胁迫能力最强。

【Objective】Effect of exposure to light of varied spectra at night on the cold tolerance of tomato(Lycopersicon esculentum)seedlings was investigated.【Method】Tomato seedlings grown under supplemental lighting at night by using white(W),red(R)or blue(B)light or combined 2 R/8 B,5 R/5 B or 8 R/2 B were taken as treatments,and seedlings grown under natural conditions were taken as control.After 20 d of cultivation,the plants were subjected to a low-temperature stress of 10/5℃(day/night temperatures)to determine the tolerance of the seedlings toward mild hypothermia.【Result】The ranges of increased electrolyte permeability and MDA content in the leaves of the treatment seedlings under low-temp stress were significantly lower than those of control.After being exposed at night to the combination of 2 R/8 B,5 R/5 B or 8 R/2 B,the seedlings could maintain high activities of SOD,CAT,and POD under the low-temp stress.These activities peaked when the8 R/2 B was applied to reach significantly 399.49%on SOD,129.01%on CAT,and 135.74%on POD higher than those of CK,6 d after the seedlings were moved to the low-temp environment.【Conclusion】Exposing tomato seedlings to light of different spectra at night improved the ability of the plants to tolerate mild hypothermia.The effect was maximized when the seedlings were grown for 20 d under the nighttime lighting with 8 red and 2 blue lamps.