16个玉米品种通过建立5、10℃低温下萌发的种子活力指标综合体系表明,玉米种子萌发对低温的敏感期在萌发后12 h,玉米耐低温萌发能力鉴定可在此期间进行.根据5℃和10℃低温对各品种种子萌发的发芽率、发芽势、发芽指数和活力指数的综合变化,郑单958和吉单415为萌发期耐低温强的品种,铁单18和辽单632为耐低温性差的品种.10℃低温下4项指标可以构建综合活力指标,郑单958和吉单415能维持低温下细胞膜结构和功能的稳定性,铁单18和辽单632种子萌发的低温耐性弱,细胞膜受到损伤.低温耐性强的品种在萌发早期积累高水平的可溶性糖和脯氨酸,维持细胞膜的渗透压,以抵御低温伤害,低温耐性弱的品种在后期脯氨酸含量的大幅度升高可能是受到低温伤害所致.%Sixteen varieties are used to study the effect on vigor of seed germination stage for maize chilling tolerance and its physiological mechanism under different low temperature.The results showed that seed germination index and vigor index can reflect the difference of chilling tolerance between low temperatures (5,10 ℃ ).The indexes of 10 ℃ is well corresponding with their ability of low temperature tolerance.The optional identification stage is during 12 h after normal temperature germinating.And the relative elongation rate of germinating seed can well reflect the chilling tolerance ability of low temperature tolerance.So the relative elongation rate of seed under low temperature can show the difference temperature tolerance among varieties.Seed vigor comprehensive index may also constitute an appraisal system that can explore maize germinating seed low temperature tolerance.zhengdan958 and jidan415 is the strongest resistance; tiedanl8 and liaodan632 is the weakest resistance.The high chilling-resistance cultivar showed small raising trend of these indexes,lower permeability of plasma membrane and production of MDA,and induction of more proline content at the same low temperature.
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