赤霉素浸种对玉米低温出苗率的影响

Effects of Gibberellin Presoaking on Maize Germination under Chill

研究单一低温胁迫和低温干旱双重胁迫对不同耐寒性玉米品种的籽粒萌发特性和苗期生理生化性能的影响,并比较不同浓度赤霉素溶液浸种的抗逆效果。以抗寒性较强的郑单958和抗寒性较弱的CB15098为供试品种,设置低温单一胁迫和低温干旱双重胁迫2种逆境,研究10,50,100 mg/L的赤霉素浸种对玉米籽粒萌发和苗期生长的影响。结果表明,赤霉素浸种效果表现为在单一胁迫下增加不同耐寒性玉米的地上部干、鲜质量,在双重胁迫下减少两玉米品种浸种后的地上部干、鲜质量。对抗寒性较强的郑单958,赤霉素浸种可增加其低温和低温干旱胁迫下的地上部高度;对抗寒性较差的CB15098,浸种显著提升其低温和低温干旱胁迫下的发芽势,浸种在低温胁迫下抑制CB15098地上部高度和根系长度,在低温干旱胁迫下促进CB15098地上部高度。抗寒性较强的郑单958发芽率、地上部干、鲜质量和高度对不同浓度赤霉素浸种的响应幅度均高于抗寒性较弱的CB15098。低温干旱胁迫下建议采用低浓度赤霉素浸种。单一低温胁迫下建议采用高浓度赤霉素浸种,低温干旱复合胁迫下采用低浓度赤霉素浸种抗逆效果更佳。

The objective of this experiment is to study the effects of chill and drought stresses on seed germina- tion characteristics,and the effects of stresses resistance by presoaking with gibberellin （ GA3 ） under different concentrations. An experiment was conducted in order to investigate the effect of chill stress and chill-drought double stresses on gemination and seedling growth,the difference of the effects of presoaking with GA3 was also analyzed. Two varieties of Zhengdan 958（ZD958 with good cold resistence）and CB15098（ CB15098 with poor cold resistence） were presoaked in gibberellin solution with three concentrations （10,50,100 mg/L）before sowing. The result showed that the effect of gibberellin presoaking on dry and fresh weight of shoot exhibited the opposite effect under two kinds of stress：the promoting effect under chili stress and the inhibition effect under double stresses. ZD958 had better chill resistance in compared with CB15098,and shoot elongation of ZD958 was promoted by presoaking with GA3 under both chill and chill-drought double stresses. GA3 presoaking increased germinability of CB15098 under both stresses as well as its shoot length under double stresses, contrary to its decreased plant length under chili stress, The responses of germination, fresh and dry weight and length of shoot of ZD958 was significantly higher than CB15098. Lower concentration of GA3 presoaking was recommended for maize variety under chili and drought stresses. High concentration of gibberellin solution was recommended for seed soaking under single chill stress,and low concentration of gibberellin solution for seed soaking was better for maize under chill and drought stress.