2个农单玉米新品种及亲本的苗期抗旱性分析

Drought Resistance of Two New Varieties and Their Parents of Nongdan Series Maize at Seedling Stage

【目的】探明2个农单玉米新品种及其亲本的苗期抗旱性,为玉米抗旱品种的选育提供理论依据。【方法】以玉米杂交种农单476、农单145、先玉335(CK)及其亲本自交系为材料,以15%浓度的PEG-6000溶液模拟干旱条件对幼苗进行干旱处理,测定玉米杂交种及亲本自交系在干旱胁迫下的株高、叶面积、地上部干鲜重、根系干鲜重、根冠比、抗氧化酶活性、丙二醛含量和脯氨酸含量,分析各材料的苗期抗旱性。【结果】干旱处理的玉米株高、叶面积较正常处理下降,株高、叶面积的干旱伤害率杂交种依次为农单145>农单476>先玉335,自交系依次为农系376>农系3435>PH4CV。干旱胁迫后,玉米抗氧化酶活性和膜脂透性升高,SOD抗旱系数表现为:杂交种农单476>农单145>先玉335,自交系农系376>农系3435>PH4CV;POD抗旱系数为杂交种农单145>农单476>先玉335,自交系农系3435>农系376>PH4CV;Pro含量变化幅度:杂交种农单476>农单145>先玉335,自交系农系3435>农系376>PH4CV。【结论】杂交种农单476性状表现优异,与其父本农系3435各性状的优良表现相吻合,其杂交种的抗旱优良基因来源于父本农系3435。

【Objective】The drought resistance of two new varieties and their parents of Nongdan series Maize at seedling stage is determined to provide the theoretical basis for breeding of maize varieties with good drought resistance.【Method】The height,leaf area,fresh and dry weight of aboveground part,fresh and dry roots weight,root/shoot ratio,antioxidant enzyme activity,MDA content and proline content of Nongdan 476,Nongdan 145,Xianyu 335(CK)and their parental inbred lines are determined under the imitative drought stress of 15%PEG-6000 solution to analyse their drought resistance at seedling stage.【Result】The height,leaf area of tested hybrid maize varieties and inbred lines under the imitative drought stress decrease compared with CK(no imitative drought stress).The injury rate of the height,leaf area are Nongdan 145>Nongdan 476>Xianyu 335 in hybrid varieties and Nongxi 376>Nongxi 3435>PH4CV in parental inbred lines.After drought stress,the antioxidant enzyme activity and membrane premeability increase.The SOD drought-resistance index is Nongdan 476>Nongdan 145>Xianyu 335 in hybrid varieties and Nongxi 376>Nongxi 3435>PH4CV in parental inbred lines.The POD drought-resistance index is Nongdan 145>Nongdan 476>Xianyu 335 in hybrid varieties and Nongxi 3435>Nongxi 376>PH4CV in parental inbred lines compared with CK(no imitative drought stress).The Pro drought-resis-tance index is Nongdan 476>Nongdan 145>Xianyu 335 in hybrid varieties and Nongxi 3435>Nongxi 376>PH4CV in parental inbred lines compared with CK(no imitative drought stress).【Conclusion】The performance of Nongdan 476 with excellent drought resistance traits is consistent with Nongxi 3435,the male parental inbred line,which indicates that the good drought resistance gene of Nongdan 476 is from Nongxi 3435,the male parental inbred line.