【摘要】 以冷敏高粱晋303为试验材料,幼苗三叶期用不同浓度的脯氨酸处理后, 2～4℃低温胁迫,测定相关生理指标,探讨外源脯氨酸处理对高粱幼苗耐冷性的影响。结果表明,外源脯氨酸处理可以提高低温胁迫下高粱叶片SOD、POD的活性,分别在3 mmol·L^-1和5 mmol·L^-1浓度脯氨酸的处理提高幅度最大。外源脯氨酸处理能降低低温胁迫下高粱叶片MDA的含量,以5 mmol·L^-1脯氨酸的处理效果最好。外源脯氨酸处理对叶片可溶性糖含量的增加也有作用,在本试验脯氨酸浓度设置范围内,可溶性糖含量随处理浓度的增加而增加。外源脯氨酸处理可以维持高粱幼苗中较高的叶绿素含量,喷施5 mmol·L^-1浓度脯氨酸时幼叶叶绿素含量最高。说明外源脯氨酸处理可有效缓解低温胁迫对高粱幼苗的伤害,提高幼苗的耐冷能力。更多还原

【Abstract】 Using cold-sensitive sorghum Jin 303 as experimental material, different concentrations of proline（Pro） were used to treat sorghum seedlings at three-leaf stage, and then low temperature stress was carried out at 2-4 ℃. The effects of exogenous Pro treatment on cold tolerance of sorghum seedlings were studied by measuring physiological indexes. The results showed that exogenous Pro treatment could increase the activity of SOD and POD in sorghum leaves under low temperature stress, the highest increase was achieved in proline treatment at 3 mmol·L^-1 and 5 mmol·L^-1 concentrations respectively. It also reduced MDA content in Sorghum leaves under low temperature stress, and the best performance was obtained at 5 mmol·L^-1. Besides, exogenous Pro treatment also had an effect on the increase of soluble sugar content in leaves. Within the concentration setting range of Pro in this experiment, the soluble sugar content increased with the increase of treatment concentration. Exogenous proline treatment could maintain high chlorophyll content in Sorghum seedlings, and the chlorophyll content in young leaves was the highest when proline was sprayed at 5 mol·L^-1 concentration. This indicated that exogenous proline treatment could effectively alleviate the damage to Sorghum Seedlings under low temperature stress and improve the cold tolerance of seedlings.更多还原