Effect of endogenous hormones content changing on the chilling tolerance in maize seed germination | 低温胁迫对玉米种子萌发过程中内源激素含量变化的影响

chinois. 经10℃低温处理,耐冷品系玉米杂交种郑单958、吉单415和冷敏感品系辽单632、铁单18萌发期种子内源激素含量变化与适温处理相比变化趋势相同,GA3含量先升高再下降,ABA含量逐渐下降。耐冷品系郑单958和吉单415在低温处理条件下,GA3含量初期有所下降后明显升高,低温处理9d达到峰值,分别为416.79ng.g-1和441.36ng.g-1,上升幅度比辽单632、铁单18大。耐冷品系内源激素ABA含量下降的趋势较缓,并保持较高水平,分别为575.2ng.g-1和596.52ng.g-1,铁单18和辽单632仅为466.23ng.g-1和354.63ng.g-1。GA3/ABA在不同品系中变化明显,呈波动性变化,耐冷品系郑单958和吉单415值较小且变化幅度小。低浓度ABA浸种预处理促进种子萌发,可提高萌发期种子的耐冷性,高浓度则抑制种子萌发;各浓度GA3预处理促进低温下各品系种子的萌发,有利于幼苗和根系的生长。

anglais. Under 10℃ treatment,four maize varieties were used to study the changes of ABA and GA3 endogenous hormones contents on seed germination stage for maize chilling-tolerance.The chilling-resistance cultivars showed more endogenous GA3 contents than chilling-sensitive line,raising and then decreasing at normal and low temperature.The GA3 contents of chilling-tolerance line(Zhengdan958 and Jidan415) increased to the highest level(416.79ng•g-1 and 441.36ng•g-1) after 9d 10℃ treatment.The results indicated that Zhengdan958 and Jidan415 could maintain a higher endogenous ABA(575.2ng•g-1and 596.52ng•g-1)and lower GA3/ABA under low temperature during seed germinating.Tiedan18 and Liaodan632 had more dramatically changes than Zhengdan958 and Jidan415.This also indicated that these indexes may affect chilling-tolerance among different cultivars.Effects of exogenous hormones on the seed germination vigor and seedlings growth were tested to improve chilling-tolerance at low temperature.The best resist-chilling concentration is GA35mg•L-1,ABA10mg•L-1.