[关键词]
[摘要]
为探究外源6-苄氨基嘌呤(6-BA)对低温胁迫下玉米幼苗生理响应的调节作用,以德美亚3号为试验材料,在人工气候箱中进行盆栽试验。设置4个处理,分别为25℃下叶面喷施清水(CK)、25℃下叶面喷施6-BA(6-BA)、5℃下叶面喷施清水(LT)、5℃下叶面喷施6-BA(LT+6-BA)。5℃处理7天后25℃处理3天。结果表明,常温(25℃)条件下外源6-BA对玉米幼苗的的生长具有一定的促进效果。而低温(5℃)胁迫诱导膜脂过氧化产物的大量积累,光合能力降低,抑制玉米幼苗的生长。在低温条件下,6-BA处理能改善根系生长情况,提高叶绿素含量、净光合速率、气孔导度及最大光化学效率;同时提高了抗氧化酶活性,使H2O2和MDA的含量降低,缓解低温胁迫对玉米幼苗生长的抑制程度。在常温恢复阶段,外源6-BA能加快玉米幼苗的恢复速率。综上所述,外源 6-BA 在低温胁迫条件下能通过提高玉米幼苗的光合能力和抗氧化酶活性,降低膜脂过氧化物含量而提高玉米幼苗对低温的抵抗能力。
[Key word]
[Abstract]
In order to investigate the regulation of exogenous 6-benzaminopurine (6-BA) on physiological response of maize seedlings under low temperature stress, we used " Demeiya 3" maize variety as experimental material and conduct pot experiments in an artificial climate chamber. Four treatments were set up, foliar spraying of water at 25℃(CK), foliar spraying of 6-BA at 25℃ (6-BA), foliar spraying of water at 5℃ (LT), foliar spraying of 6-BA at 5℃(LT+6-BA). The maize seedlings were treated at 5℃ for 7 days and 25℃ for 3 days. The results showed that, 6-BA had certain stimulative effect on the growth of maize seedlings under normal temperature (25℃). while low temperature (5℃) stress induced a large accumulation of membrane lipid peroxidation products,?reduced photosynthetic capacity and inhibited the growth of maize seedlings. 6-BA treatment under low temperature stress led to a increase in root growth, chlorophyll content, net photosynthetic rate, stomatal conductance and maximum photochemical efficiency . At the same time, the activity of antioxidant enzymes was increased, the contents of H2O2 and MDA were decreased, and the inhibition degree of low temperature stress on the growth of maize seedlings was alleviated. Exogenous 6-BA could accelerate the recovery rate of maize seedlings at normal temperature. In conclusion, exogenous 6-BA can improve the resistance of maize seedling to low temperature by improving photosynthetic capacity, antioxidant enzyme activity and reducing the content of membrane lipid peroxides of maize seedlings under low temperature stress.
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[基金项目]
黑龙江省自然科学基金联合引导项目(LH2021C024)、东北农业大学“青年才俊”项目(20QC02)、农业部种子管理局“绿色品种特性鉴定评价专项 ” (111721301354052342)