广西玉米品种萌芽期生理生化特性及其抗旱性综合评价

【目的】依据生理生化指标评价广西玉米品种萌芽期抗旱性，为广西抗旱玉米品种筛选和培育提供参考。【方法】利用20% PEG-6000溶液模拟干旱胁迫，对14个广西玉米品种进行萌芽期抗旱性试验，测定对照（蒸馏水）和干旱胁迫下各玉米品种胚芽的叶绿素、可溶性糖和丙二醛（MDA）含量及超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性，探究干旱胁迫对玉米萌芽特性的影响，并采用隶属函数法综合评价各参试玉米品种萌芽期的抗旱性。【结果】与对照相比，干旱胁迫下各参试玉米品种的生长发育均受到明显抑制，表现出种子萌发困难，胚芽生长缓慢，但不同品种受到的影响存在差别。方差分析结果表明，各生理生化指标在品种间和处理间的差异均达极显著水平（P<0.01）。与对照相比，干旱胁迫下各玉米品种的叶绿素和可溶性糖含量减少，SOD、POD和CAT活性降低，MDA含量增加。隶属函数法评价中指标权重系数最大为MDA含量，达46.96%，其次为SOD活性，为21.77%。各品种隶属函数法D值在0.176~0.795，其中兆玉215和桂单162的D值大于0.7，属于强抗旱品种；桂单6205、桂单666和兆玉200的D值在0.5~0.7，属于抗旱品种；桂单660、桂单658、桂单673、桂单6209、桂单203和桂单6203的D值在0.4~0.5，属于中抗旱品种；桂单669、桂单671和桂单668的D值小于0.4，属于弱抗旱品种。【结论】叶绿素、可溶性糖和MDA含量及SOD、POD和CAT活性均可作为玉米萌芽期抗旱性评价指标，其中以MDA含量和SOD活性为主要评价指标。14个玉米品种中，兆玉215、桂单162、桂单6205、桂单666和兆玉200的抗旱性相对较强。

Comprehensive evaluation of physiological and biochemical characteristics and drought resistance of maize varieties during the germination stage in Guangxi

【Objective】Physiological and biochemical indices were used to evaluate the drought resistance of maize varieties in the Guangxi region during the germination stage,so as to provide a reference for the selection and cultivation of drought resistant maize varieties in Guangxi.【Method】Using 20% PEG-6000 solution to simulate drought stress,the drought resistance test was carried out on 14 maize varieties in Guangxi during the germination stage. The contents of chlorophyll,soluble sugar and malondialdehyde(MDA),and the activities of superoxide dismutase(SOD),peroxidase (POD)and catalase(CAT)of each maize variety's germ under control conditions(distilled water)and drought stress were measured to explore the effect of drought stress on maize germination characteristics. The evaluation of the drought resistance of the different maize varieties used the membership function method.【Result】Compared with the control,the growth and development of all tested maize varieties were significantly inhibited under drought stress,showing difficult seed germination and slow embryo growth,but different varieties were affected differently. The differences of each physiological and biochemical index among varieties and treatments reached extremely significant levels(P<0.01). Compared with the control,the contents of chlorophyll and soluble sugar,the activities of SOD,POD and CAT were decreased, while the MDA content increased under drought stress. In the evaluation of the membership function method,the largest index weight coefficient was the MDA content,reaching 46.96%,followed by SOD activity,reaching 21.77%. The D value of varieties membership function method were between 0.176 and 0.795,among which the D value of Zhaoyu 215 and Guidan 162 were greater than 0.7,belonging to the strongly drought resistant varieties;the D value of Guidan 6205, Guidan 666 and Zhaoyu 200 were between 0.5 and 0.7,belonging to drought resistant varieties;the D value of Guidan 660,Guidan 658,Guidan 673,Guidan 6209,Guidan 203 and Guidan 6203 were between 0.4 and 0.5,belonging to middle drought resistant varieties;and the D value of Guidan 669,Guidan 671 and Guidan 668 were less than 0.4,belonging to weakly drought resistant varieties.【Conclusion】The contents of chlorophyll,soluble sugar,MDA,and the activities of SOD,POD and CAT could be used as drought resistance evaluation indices during the maize germination stage,among which MDA content and SOD activity provide the strongest evaluation indices. Zhaoyu 215,Guidan 162,Guidan 6205, Guidan 666 and Zhaoyu 200 showed the strongest drought resistance of the 14 maize varieties tested.