【摘要】 为了研究外源独角金内酯（GR24）对重金属铅胁迫下番茄幼苗生长生理的影响，以番茄品种上海红宝石908为材料，在河池学院植物生理材料培养室进行试验，培养室平均温度28℃，平均相对湿度为70.85%。选择生长状态较为一致且为3叶1心的番茄幼苗移栽至1/2 Hoagland营养液中，试验共设4个处理，CK（完全营养液）、GR24(完全营养液+50 nmol·L^-1GR24)、Pb(完全营养液+200 mg·L^-1Pb)、Pb+GR24(完全营养液+200 mg·L^-1Pb+50 nmol·L^-1GR24)。研究了GR24对正常生长和铅胁迫下番茄幼苗的长势、抗氧化系统和渗透调节物质等的影响。结果表明，与CK相比，200 mg·L^-1的Pb胁迫处理番茄幼苗的株高、根长、单叶面积分别降低了21.03%、35.15%、27.27%。与单独Pb胁迫处理相比，施加外源GR24可以明显提高番茄幼苗叶片中叶绿素、类胡萝卜素、可溶性糖、可溶性蛋白含量（SP）和生物积累量；显著提高POD、CAT等抗氧化酶活性和根系活力；降低植株叶片H₂O₂、O₂^-·、脯氨酸和MDA含量。综上，外源施加50 nmol·L^-1的GR24能加快铅胁迫下番茄幼苗叶绿素合成速度，提高叶片抗氧化能力，促进番茄苗期生长，缓解铅胁迫对番茄幼苗生长的毒害作用。更多还原

【Abstract】 In order to study the effect of exogenous GR24 on the growth physiology of tomato seedlings under heavy metal Pb stress,the tomato variety Shanghai Ruby 908 was used as the experimental material.The experiment was conducted in a plant physiological material culture room,with an average temperature of 28℃and an average relative humidity of70.85%.Tomato seedlings with consistent growth status and three leaves and one heart were transplanted into 1/2Hoagland nutrient solution.The experiment included four treatments:CK（complete nutrient solution）,GR24(complete nutrient solution+50 nmol·L^-1GR24),Pb(complete nutrient solution+200 mg·L^-1Pb),and Pb+GR24(complete nutrient solution+200 mg·L^-1+50 nmol·L^-1GR24).The results showed that the Pb stress of 200 mg·L^-1reduced the plant height,root length,and single leaf area of tomato seedlings by 21.03%,35.15%,and 27.27%,respectively.Compared with individual Pb stress treatment,applying exogenous GR24 can significantly increase the content of chlorophyll,carotenoids,soluble sugars,soluble proteins,and bioaccumulation in tomato seedling leaves;significantly increase the activity of antioxidant enzymes such as SOD,POD,CAT,and root activity;reduce the content of H₂O₂,O₂O^-2-·,proline and MDA in leaf.Therefore,exogenous application of 50 nmol·L^-1GR24 can alleviate the toxic effect of Pb stress on the growth of tomato seedlings.更多还原