CaCl_2对低温胁迫及恢复后玉米自交系种子萌发及幼苗生理特性的影响

Effects of CaCl_2 on Maize Inbred Lines Seed Germination and Seedling Physiological Characteristics under Low Temperature Stress and Recovery

为探究CaCl_2对低温胁迫及恢复后玉米自交系种子萌发及幼苗生理特性的影响,确定低温胁迫下对玉米缓解程度最显著的最适CaCl_2浓度。以玉米自交系掖478、杂C-546为材料,采用浸种、叶面喷施以及浸种+喷施外源CaCl_280,160 mmol/L不同浓度处理,比较分析2种玉米种子在低温胁迫及恢复常温情况下发芽率、发芽势、发芽指数和幼苗叶片相对电导率、可溶性蛋白、Pn、Fv/Fm、POD和SOD活性等生理生化指标的变化。结果表明,在低温胁迫下,与低温下未进行CaCl_2处理的玉米自交系种子相比,2种类型玉米在80 mmol/L CaCl_2处理下种子的发芽率、发芽势、发芽指数均明显提高,幼苗相对电导率降低,净光合速率增强,POD和SOD活性提高;常温恢复生长3 d后,2种类型玉米幼苗在2种CaCl_2浓度处理下的净光合速率和Fv/Fm值呈上升趋势,其他指标恢复正常。80 mmol/L CaCl_2浸种+喷施方法的处理对玉米低温胁迫的缓解效果最佳,掖478变化幅度小,抗冷性较强;杂C-546变化幅度大,抗冷性较弱。

In order to explore the effects of CaCl2 on maize inbred lines seed germination and seedling physiological characteristics under low temperature stress and recovery,determining the optimum CaCl2 concentration was the most significant effect on the mitigation of maize under low temperature stress.Used maize inbred lines Y-478,ZC-546 as the materials,the effects of two kinds of maize seeds were studied by soaking,spraying and composite processing CaCl2 80,160 mmol/L.The germination rate,germination potential,germination index and relative conductivity,soluble protein,Pn,Fv/Fm,POD and SOD activities were observed under low temperature stress than returned to normal temperature conditions.The results showed that under the low temperature stress,compared with the maize inbred lines without CaCl2 treatment at low temperature,the germination rate,germination potential and germination index of the two types of maize were significantly increased under 80 mmol/L CaCl2 treatment,the relative conductivity of the seedlings decreased,the net photosynthetic rate increased,the activity of POD and SOD increased,the net photosynthetic rate and Fv/Fm of the two types of maize seedlings showed an upward trend at the two CaCl2 concentrations,and the other indexes returned to normal.The 80 mmol/L CaCl2 composite processing method to alleviate the best effect of low temperature stress on maize,Y-478 of the change range was small and had the strongest cold resistance,ZC-546 of the change range was large and had a weak cold resistance.