【作者】 樊趁英；

【导师】 夏凯； 徐建明；

【作者基本信息】 南京农业大学 ， 植物学， 2008， 硕士

【摘要】 烯效唑（S-3307）、赤霉素（GA₃）和激动素（KT）与草甘膦混用后,通过对玉米幼苗地上部鲜重、株高、叶绿素含量、丙二醛（MDA）累积量和保护酶系统的影响,分析它们对草甘膦活性的缓解或促进作用,从中筛选出与草甘膦混用的植物生长调节剂的最佳浓度,以达到降低除草剂用量,提高除草效果和对作物安全性。研究结果如下:S-3307（10、25、50）mg/L与草甘膦混用后,使玉米幼苗地上部鲜重显著增加,处理8d后,其中50 mg/L S-3307与草甘膦混用处理是单剂草甘膦处理的2-31倍。单独施用草甘膦使玉米幼苗的叶绿素含量显著下降,S-3307混用后提高了叶绿素含量,到第9d时10、25、50mg/L S-3307与草甘膦混合处理的幼苗叶绿素含量分别是单剂草甘膦处理的1.77、1.58和1.96倍。MDA累积量随着S-3307浓度的升高而降低,第7d时10、25、50 mg/L S-3307与草甘膦混合处理的幼苗中MDA累积量比单剂草甘膦分别降低了35.15%、44.54%和52.44%。S-3307混合处理不同程度地提高了SOD、POD、CAT的活性。S-3307可能通过提高抗氧化酶活性来保护膜的结构和功能,降低膜脂的过氧化,缓解草甘膦对玉米幼苗的伤害作用。与单独施用草甘膦相比,不同浓度的GA₃（10、50、100）mg/L和KT（5、10、20）mg/L分别与草甘膦混用后都显著地抑制了玉米幼苗的地上部鲜重。其中100 mg/L GA₃与草甘膦混用,处理6d后的株高比单剂草甘膦增加了11.20%,处理8d后,玉米幼苗的地上部鲜重比单剂草甘膦处理减少了76.33%。GA₃和KT分别与草甘膦混用,均提高了玉米幼苗叶片中叶绿素含量的下降幅度。MDA累积量急剧增加,且随着GA₃和KT的浓度的升高而增加。叶片中的SOD、POD活性都呈先升高后下降的趋势,且比单独施用草甘膦先达到峰值,而后急剧下降,说明随着处理时间的延长,胁迫加重超出了其承受范围,两种酶的活性就下降。暗示GA₃和KT可能降低了幼苗对草甘膦的抗性达到增效的效果。实验结果表明:S-3307与草甘膦混用对玉米幼苗的伤害均有缓解作用,以50 mg/LS-3307缓解效果最佳。GA₃和KT分别与草甘膦混用后对草甘膦的活性具有增效作用,且100 mg/L GA₃和20 mg/L KT增效效果最佳。更多还原

【Abstract】 In order to explore a new method of reducing dose of glyphosate usage and increasing its activity in weed control,the impacts of uniconazole（S-3307）,gibberellin acid（GA3） and kinetin（KT） on activities of glyphosate in maize seedlings on shoot fresh weight,plant height,chlorophyll content,MDA accumulation and protective enzyme system were studied.After foliar spray of mixture solutions of S-3307（10、25 and 50） mg/L and glyphosate to maize seedlings,shoot fresh weight and chlorophyll content were increased.After 8 days treatment with a mixture of 50 mg/L S-3307 and glyphosate,the root fresh weight showed a 2.31 fold increase compared to single glyphosate only.Glyphosate caused a significant decrease in leaf chlorophyll content,which was increased to 1.77,1.58 and 1.96 folds, respectively,by 10,25 and 50 mg/L S-3307 after 9 days treatment.After 7 days treatment, 10,25 and 50 mg/L S-3307 decreased MDA accumulation in leaves by 35.15%,44.54% and 52.44%of that treated with glyphosate.The superoxide dismutase（SOD） and peroxidase（POD） and catalase（CAT） activities were also increased by S-3307.These results suggested that S-3307 might reduce glyphosate toxicity due to increase the resistance of seedlings against glyphosate.When treating maize seedlings with mixture solutions of glyphosate and GA₃ or KT, shoot fresh weight was inhibited significantly.After 6 days treatment with a mixture of 100 mg/L GA₃ and glyphosate,plant height was increased by 11.20%,and after 8 days treatment shoot fresh weight was decreased by 76.33%.GA₃ or KT reduced chlorophyll content,and increased MDA accumulation.The activities of SOD and POD also affected by GA₃ or KT.The results indicated that GA₃ and KT could decrease plant resistance to glyphosate.In conclusion,S-3307 showed an antagonistic,while GA₃ and KT,agonistic effects to glyphosate activity.The suitable concentration for S-3307,GA₃ and KT were 50,100 and 20 mg/L,respectively.更多还原