干旱胁迫及复水对不同黍稷品种根系生理特性的影响

以2种抗旱性不同的黍稷品种(‘陇糜4号’和‘晋黍7号’)为试验材料,采用盆栽试验研究了苗期中度和重度干旱胁迫后拔节期复水对其根系生理特性的影响。结果显示:(1)干旱胁迫引起2个黍稷品种根系活力明显下降,根系SOD、POD活性以及MDA、脯氨酸含量明显升高,而且重度干旱胁迫处理变化幅度显著大于中度干旱胁迫。(2)复水后,2个黍稷品种根系的各项生理指标均有不同程度的恢复,且中度胁迫处理较易恢复,重度胁迫下恢复能力很弱。(3)2个黍稷品种根系各项生理指标在干旱胁迫及复水条件下变化幅度不同,干旱胁迫下抗旱性强的‘陇糜4号’根系活力下降幅度明显低于抗旱性弱的‘晋黍7号’,根系SOD活性、POD活性、MDA含量和脯氨酸含量的上升幅度明显高于‘晋黍7号’,而复水后‘陇糜4号’根系的各项生理指标的恢复能力明显强于‘晋黍7号’。研究表明,干旱胁迫及复水条件下‘陇糜4号’均表现出较高的根系活力、保护酶活性和脯氨酸含量,且MDA含量较低,从而表现出较强的抗旱性。

Effect of Drought Stress and Rewatering on Physiological Characteristics of Roots in Different Proso Millet Varieties

With two different drought-resistant proso millet varieties(’Longmi 4’ and ’Jinshu 7’),the physiological effect were studied under the conditions of moderate and severe drought stress at seedling and rewatering at erect seedling stage in pot culture.The main result showed that:(1)under drought stress,the roots activity decreased,the activities of SOD and POD and contents of MDA and proline all increased.The effects were stronger under severe drought stress than under moderate drought stress.(2)After rewatering,the tested various physiological indexes of two different proso millet varieties had different degrees of recovery,and the recovering abilities were strong under moderate drought stress,but weak under severe stress.(3)The tested various physiological indexes of two different proso millet varieties had different amplitude under drought stress and rewatering condition.Under drought stress,the roots activity of drought-tolerant ’Longmi 4’ was less than that of drought-sensitive ’Jinshu 7’,but the ascending extent of the activities of SOD and POD and contents of MDA and proline were larger than those of drought-sensitive variety ’Jinshu 7’.After rewatering,compared with ’Jinshu 7’,’Longmi 4’ had higher recovering ability.So the conclusions are that:under drought stress and after rewatering,’Longmi 4’ keeps higher root activity,SOD activity,POD activity and proline contents,but lower MDA content,which are physiological basis of stronger drought resistance.