简介：Cadmium(Cd)ishighlytoxictoplants,animals,andhumans.Limitedinformationisavailableontheroleofnitricoxide(NO)and/or24-epibrassinolide(EBR)inresponseofplantstoCdstress.Inthisstudy,ahydroponicexperimentwasperformedtoinvestigatetheeffectsofNOand/orEBRonpeanutplantssubjectedtoCdstress(200μmolL-1)withsodiumnitroprusside(SNP,anexogenousNOdonor)(250μmolL-1)and/orEBR(0.1μmolL-1)addition.TheresultsshowedthatCdexposureinhibitedplantgrowth,andthisstresswasalleviatedbyexogenousNOorEBR,andespeciallythecombinationofthetwo.TreatmentwithCdinhibitedthegrowthofpeanutseedlings,decreasedchlorophyllcontent,andsignificantlyincreasedtheCdconcentrationinplants.Furthermore,theconcentrationofreactiveoxygenspecies(ROS)markedlyincreasedinpeanutseedlingsunderCdstress,resultingintheaccumulationofmalondialdehyde(MDA)andprolineinleavesandroots.UnderCdstress,applicationsofSNP,EBR,andespeciallythetwoincombinationsignificantlyreducedthetranslocationofCdfromrootstoleaves,increasedthechlorophyllcontent,decreasedtheconcentrationsofROS,MDA,andproline,andsignificantlyenhancedtheactivitiesofsuperoxidedismutase(SOD),peroxidase(POD),andcatalase(CAT)inpeanutseedlings.ExogenousNOand/orEBRalsostimulatedtheactivitiesofnitratereductase(NR)andnitricoxidesynthase(NOS)andincreasedthecontentsofantioxidants,suchasascorbicacid(AsA)andreducedglutathione(GSH).Furthermore,exogenousNOand/orEBRenhancedCdaccumulationinthecellwallandthusdecreasedCddistributionintheorganellesintheroots.Theconcentrationsofcalcium(Ca),iron(Fe),magnesium(Mg),andzinc(Zn)werealsoregulatedbyexogenousNOorEBR,andespeciallybythetwoincombination.TheseresultsindicatedthatSNPandEBR,aloneandparticularlyincombination,canmitigatethenegativeeffectsofCdstressinpeanutplants.

简介：土壤侵蚀过程复杂，很难直接应用土壤侵蚀预报方程进行定量计算。作为一种新的机器学习算法，支持向量机在样本有限的情况下，采用结构风险最小化准则，把学习问题转化为一个二次规划问题，从而得到唯一的全局最优解。首次尝试将最小二乘支持向量机技术用于土壤侵蚀预测，并与BP神经网络的方法进行了对比，取得了较好的预测精度。