谷子孕穗期一些生理性状与品种抗旱性的关系

Relationship between Drought Tolerance Ability and Some Physiological Characteristics of Foxtail Millet at Booting Stage

探索谷子孕穗期对干旱环境的生理生化适应机制,筛选谷子孕穗期抗旱性鉴定的生理指标。利用抗旱性不同的20个谷子品种,在模拟干旱棚内通过孕穗期干旱胁迫,研究可溶性糖、脯氨酸、丙二醛(Malondialdehyde,MDA)等渗透势调节物质的含量和保护性酶活性的变化。孕穗期干旱胁迫使谷子叶片脯氨酸、可溶性糖和MDA含量增加,超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化氢酶(Catalase,CAT)的活性增高,而过氧化物酶(Peroxi-dase,POD)的活性则降低。相关分析表明,比较干旱胁迫与非干旱胁迫条件下可溶性糖、MDA含量和SOD活性的相对值与品种的抗旱指数相关性达到显著或极显著水平。水、旱条件下可溶性糖、MDA含量和SOD活性相对值可作为谷子孕穗期抗旱性鉴定指标,利用此3项相对值与抗旱指数所建立的回归方程:y=0.111x1-0.893x2+0.682x3,可预测谷子品种孕穗期的抗旱性。

Although foxtail millet is a relatively drought tolerant crop in cereals,it may still suffer from serious water stress because it is mostly grown in dry land and drought environments.To screen for drought tolerant identification index in the booting stage,some physiological characteristic were assayed by comparison between drought stress treated and normal grown foxtail millet varieties.Twenty foxtail millet cultivars with different drought tolerances were used as experimental materials.Changes in WSS（Water soluble sugar）,Pro（Prolin）,MDA（Malondialdehyde） content and antioxidative enzyme activities were studied under both irrigation and drought stress conditions at the booting stage.The results indicated that the contents of WSS,Pro,and MDA increased to a higher level in drought stress treatment,the enzymatic activities of superoxide dismutase（SOD） and catalase（CAT） also increased,but that of peroxidase（POD） decreased in the leaves treated at the booting stage.Correlation analysis showed that the drought tolerant coefficient significantly or very significantly correlated with relative contents of WSS,MDA and SOD activity under irrigation and drought conditions.Results obtained concluded that the relative content of WSS and MDA,and the relative activity of SOD could be selected as identification indexes for drought tolerance ability test at foxtail millet booting stage.A stepwise regression equation was established using the three characters,which is y=0.111x1-0.893x2＋0.682x3,and test with the algorithm indicating its efficiency and reliability.