细绿萍(Azolla+filiculoides)对含铅培养液净化和适应.pdfVIP

摘 要 细绿萍 (AzollafiliculoidesLamk)是繁殖速度快、光合固氮能力强的水 生厥类植物，广泛地用于饲 (肥)料及污水净化。本文对其生长规律、净化铅的 特点以及光照条件对细绿萍除铅的影响进行了探讨。 根据细绿萍在不同浓度的Hoagland稀释液中的生长状况，考虑到细绿萍生 长的营养供给及一些阴离子如((SOX一易与铅离子产生沉淀物两方面的因素，选择 以Hoagland稀释液配制不同浓度铅溶液。在本实验条件下，细绿萍在Hoagland 稀释液中的生物量和个体数量符合指数增长。随铅浓度的升高细绿萍体内铅的富 集量明显增加，其富集铅可分为生理富集期、平台期、受害富集期;与此同时， 细绿萍自身也受到一些影响;随铅浓度增加及培养时间的延长，其叶绿素含量减 少，过氧化物酶活性增加，且二者呈负相关((r为一97);一定浓度的铅使细绿 萍的细胞分裂受到抑制，固氮能力下降，细胞膜的破坏先于外部受害症状的出现， 受害程度加深，抑制新根的萌发，但对不定根的脱落影响不大。细绿萍在不同光 照强度、铅浓度为一定的条件下实验，结果表明，遮光有利于细绿萍对铅的富集， 适宜的光照强度有利于叶绿素的合成。 关键词:细绿萍;生物董;个体致量; 富集;光照强度;叶绿素;细燕透 性;过氧化物酶(POD)活性;核酸;总氮 PURIFICATIONANDADAPTATIONOFAZOLLAFILICULOIDESTOLEAD- CONTAMINATEDCULTURESOLUTION ABSTRACT AzollafiliculoidesLamkisakindofaquaticfernwithfastreproduction andhighabilityofN-fixation.Ithasbeenwidelyusedasfodder,fertilizer andinpurifyingpollutedwater.Thispaperstudieditsgrowthcharacteristics, theability inpurifying lead,and itstolerancetotheheavymetal. Furthermore,wealsoinvestigatedAzollaspurifyingabilityaffectedby differentlightintensities. AccordingtoAzollasgrowthpotentialindifferentHoaglandconcentrations andsomeanionsprecipitatingPb,wechosedilutedHoaglandtocompose differentleadconcentrations.Underthisexperimentalcondition,Azollas biomassanditsindividualnumberswereinkeepingwithexponentialequation. Withtheincreaseofleadconcentration,theaccumulationofleadinAzolla obviously increased. The accumulated process may be divided into physiologicalaccumulationphase,levelphaseandpoisonedaccumulationphase. Atthesametime,Azollaitselfwasalsoaffected.Itschlorophyllcontent decreasedwhiletheactivityofPODincreased,andtheybothwerenegatively correlated(r=-0.97).Atcertainleadconcentration,Azollascelldivision wasinhibited,its abilityofnitrogen-fixationdecreasedanditscell membranesweredestroyedbeforeitssuperficialsymptomsappeared.Acertain leadconcentrationleadconcentrationrestrainednewrootsfroms