氯化胆碱对冷胁迫下的烟草幼苗的保护性效应

Protective Effectof Choline Chloride on Tobacco Under Chilling Stress at Seedling Stage

对烟草幼苗叶面喷施不同浓度 ( 0 ,50 ,10 0 ,30 0 ,50 0 ,70 0 ,10 0 0 mg· L-1)的氯化胆碱 ( CC)溶液 ,研究 CC对其在经受 3～ 4℃冷胁迫下的保护性效果。结果表明 :与对照的比较 ,经 CC处理的烟草幼苗 ,在冷胁迫下 ,其超氧物歧化酶、过氧化氢酶和过氧化物酶等活性明显较高 ,故其膜脂过氧化产物丙二醛产生量减少 ,电解质外渗率降低 ,叶绿素残存量较高 ;经 CC处理的烟草幼苗总含水量与对照的差异虽然不大 ,但其束缚水含量增高 ,自由水减少 ,原因是体内可溶性糖、可溶性蛋白质和脯氯酸含量明显增高。试验结果表明在 0℃以上冷胁迫下 ,CC对膜脂有保护作用 ,并增加了细胞内抗冷性物质 ,有利于烟草抗冷性的提高。在不同浓度的 CC处理中 ,以喷施 30 0 mg·

Tobacco(Nicotiana tabacum L.cv.K32 6 ) was sprayed with0 ,5 0 ,1 0 0 ,30 0 , 5 0 0 ,70 0 ,1 0 0 0 mg· L- 1 of choline chloride(CC) during seedling stage. One week after spraying,seedlings were treated with low temperature (3～ 4℃ ) for 36 hours. Leaves were then used as trial material.The main results were as follows: In comparison with the control,the activities of superoxide dismutase,catalase and per- oxidase increased by 2 7.0 %～ 5 4.2 % ,1 4.2 %～ 44.8% and 6 .2 %～ 5 8.9% respectively,for tobacco seedling treated with CC,and the level of malondialdehyde,as an index of peroxida- tion of membrane lipids,decreased by 1 .3%～ 1 6 .2 % ,the leakage of electrolytes decreased by0 .9%～ 2 6 .9% ,and the content of chlorophyll increased by1 .9%～ 38.1 % .The content of bound water increased by9.4%～ 41 .8% ,while the content of free water decreased by1 .0 %～ 1 6 .1 % for tobacco seedling treated with CC,as a result of the level of soluble sugar,proline and soluble protein increased by1 4.3%～ 48.4% ,34.9%～ 72 .5 % and 7.6 %～ 70 .8% in seedlings,respectively.The above results indicated thatthe CC had protec- tive effect on the membrane lipids and increased the level of protective substance for cold tolerance in tobacco seedling under chilling stress.the best protective effect was achieved with 30 0～ 5 0 0 mg· L- 1 of CC treatment.