植物营养学复习要点.docx
《植物营养学复习要点.docx》由会员分享,可在线阅读,更多相关《植物营养学复习要点.docx(24页珍藏版)》请在冰豆网上搜索。
植物营养学复习要点
植物营养学复习要点
第1章:
Questions-2
1、Howtoassess评价anelementthatisessentialtohigherplants?
(1)Agivenplantmustbeunabletocompleteitslifecycleintheabsenceofthemineralelement;
(2)Thefunctionoftheelementmustnotbereplaceablebyanothermineralelement;
(3)Theelementmustbedirectlyinvolvedinplantmetabolism-forexample,asacomponentofanessentialplantconstituentsuchasanenzyme-oritmustberequiredforadistinctmetabolicstepsuchasanenzymereaction.
2、Howmanykindsofelementsareessentialforhigherplants?
18
3、Whatarethegeneralfunctionsoftheessentialelementsforhigherplants?
Astheconstituents成分ofimportantcompoundsinplant;
Astheconstituentsoractivatorsofenzymes作为酶的成分或激活剂
Stabilizethestructureofthecell
4、Pleasedescribethegeneralcompositionofalivingplant.
Water、Drymatter(Organicmatterandashes/minerals)
5、Terms:
Hyperaccumulation,phytoremediation,Macronutrients,micronutrients,threeessentialsoffertilizer
Macronutrients:
C,H,O,N,P,K,Ca,Mg,S。
Micronutrients:
Cu,Zn,Mn,Fe,B,Mo,CI,Ni,Co。
Questions-3
1、Whatarethemainfunctionsofplantroots?
Anchoring固定theplantinthesoil
Absorptionandtranslocationofwaterandnutrients
Synthesisofphytohormones植物激素andotherorganiccompounds
Storage存储ofinorganicandorganicnutrients
2、Therearetwokindsofroots,whatarethey?
须根系(fibrousrootsystem)、直根系(taprootsystem)
3、What’sroothair?
Clusterroot?
群集根
roothair:
Roothairsaretubular管状物的tensionsoftherootepidermal表皮cellandoccurasaresultoflateralcellgrowth.
Clusterroot:
4、Therearemanyenvironmentalfactorsthataffectrootgrowth.Whatarethey?
Howtheyaffectthegrowthofroot?
Soilcompaction:
土壤容重1.1-1.3g/cm3适宜旱地作物生长。
溶液中根系细长,土壤中根系粗短。
Soiltemperature:
适宜温度:
20-25℃
Water:
“干长根,湿长苗”
Nutrient:
根系具有趋肥性
Questions-4
1、Howmanypartsofaroottipcouldbedividedinto?
Meristematiczone分生区、Elongationzone伸长区、Hairzone根冠。
2、Pleasedescribethetransversesection截面ofayoungroot
Roothairs/根毛、Epidermis/表皮、Parenchyma/皮层薄壁组织、Endodermis/内皮层、Stele/中柱。
3、What’sfreespaceinaroot?
Donnanfreespaceandwaterfreespace?
freespace:
在根的某些组织或细胞内允许外部溶液通过自由扩散进出的那些区域。
水分自由空间:
水溶性离子可自由进出的那部分空间.
杜南自由空间:
细胞组织上所带的负电菏点位而吸持阳离子排斥阳离子所占据的空间。
4、Whatareapoplastandsymplast?
Symplast:
thecytoplasmaticcontinuumformedbynumerousplasmodesmata.
共质体:
指各个活的细胞通过胞间连丝相互连在一起形成的统一体
Apoplast:
comprisesallpartsofthetissueopentosolutesandwaterwithouttheirhavingtocrossamembrane.质外体:
植物组织中细胞壁的连续体,包括细胞壁、细胞间隙和木质部导管等非原生质的部分。
5、Pleasedescribethestructureofacellmembrane.
大约等比例的蛋白质和脂质分子组成,约7to10nm厚。
Questions-5
1、Whatisactiveandpassiveabsorptionofelementsbyplantrootcells?
passiveuptake:
顺浓度或电化学梯度、不消耗能量、无选择性。
activeuptake:
逆浓度或电化学梯度、消耗能量、有选择性。
2、Whatisionpumps,ionchannels?
ionchannels:
是细胞膜上具有选择性的孔状跨膜蛋白,可以允许离子迅速透过质膜,能快速开启和关闭。
ionpumps:
3、WhyNernstEquationisusefulforinterpreting解释theiontransportintoplasma原生质membrane?
4、What,generally,isthemechanismthathasbeenproposedtoaccountfortheactiveabsorptionofionsbyroots?
载体学说(Carriertransport)、离子泵学说(Ionpump)
5、Isthedrivingforcethesameforchargednutrientsandunchargednutrientsacrossthemembrane?
Explainyouranswer.
Unchargedmolecules不带电的moveinresponseto:
differencesinconcentration(chemicalgradient)
Chargedmoleculesmoveinresponseto:
differencesinconcentration(chemicalgradient)、differencesinvoltage(electricalgradient)=electro-chemicalgradient
6、Pleasedescribethetypesoftransportersexistedinthemembranes.主动运输、被动扩散、内吞外排。
7、Km,Cmin,Imax
Imax:
maximalnetinfluxofionsintoroots离子进入根的最大量
Km:
Michaelis-Mentenconstant米氏常数
Cmin:
Concentrationofnutrientinmedium养分介质中的浓度wheninflux=efflux当进出相等
Questions-6
1、Whatisfoliarfertilization?
Theprocessofnutrientuptakebyleavesandotheraerialplantorgans(也称为根外营养).
2、Whataretheadvantagesanddisadvantagesoffoliarfertilization?
Advantages:
Preventingthefixationortransformationofnutrientsorplantgrowthregulatorsinsoils
防止养分在土壤中固定和转移。
Highuptakerateandimmediatelyinvolvingplantmetabolism吸收速度快而且立即参与代谢。
Disadvantages:
补充养分数量有限,不能满足植物对大量元素的需要;效果快,但持续时间短;一些养分难于从叶片向其他部位运输。
3、Howtoincreasetheuptakeefficiencyofnutrientsappliedbyfoliarspraying?
Nutrientspecies;ConcentrationandpHofnutrients;Wettingtime润湿时间;Leaftype;Mobilityofnutrientinplant
Questions-7
1、Whytheoccurrenceofcalciumdeficiencyisusuallyobservedinsomeplantsgrownincalcareoussoil?
2、WhytheearliestvisibledeficiencysymptomsofN,PandKappearintheolderleavesofplants?
Ca,Fe,Zn,et.aldeficiencysymptomsappearinyoungerleaves?
N,PandK在植物体可移动;Ca,Fe,Zn,在植物体不可移动。
3、Whyborontoxicityofplantisusuallyobservedinthemarginsofolderleaveswhentheconcentrationofboroninsoilisveryhigh?
4、Pleasecomparetheshortdistancetransportandlongdistancetransportofnutrientinplant.
shortdistancetransport:
Pathway:
apoplast(质外体)、symplast(共质体)
ongdistancetransport:
Pathway:
xylem['zailem]木质部、phloem['fləuem]韧皮部。
5、Whichkindsofnutrientsaremainlytransportedinapoplastinplant?
Whichnutrientsinsymplast?
主动吸收的养分以共质体运输为主途径,如K,H2PO4;
被动吸收的养分如Ca,以及以分子态吸收的养分如:
B,Si等以质外体(apoplast)途径。
6、Terms:
Shortdistancetransport;longdistancetransport;nutrientremobilization;nutrientcyclingandrecyclinginplant
Shortdistancetransport:
指养分由根表皮细胞进入根内经皮层组织到达中柱的迁移过程,又称为横向运输。
longdistancetransport:
指养分通过木质部或韧皮部由根部向地上部分或从地上部分向根部的运输,又称为径向运输。
nutrientremobilization:
器官衰老或外界养分供应不足时养分由其他部位向新生组织转移的现象。
cycling:
Theretranslocationofnutrientsinthephloemfromtheshootstotheroot.
养分由根→木质部→地上部分→韧皮部→根的循环过程。
Recycling(再循环):
Thetranslocation运输ofcyclednutrientsbackinthexylemtotheshoots.
Questions-8
1、Inthegrowthperiodofaplant,thereusuallyhaveseveralkeyperiodsfornutrientuptake,whichareveryimportantforplantgrowth.Pleasenamethem.
植物营养临界期(Criticalperiodofplantnutrition);
植物营养的最大效率期(Maximumefficiencystageofplantnutrition)
2、Therearemanyenvironmentalfactorsinfluencingionabsorptionofroot.Whatarethey?
Light、temperature、water、pH、aeration通气性、nutrientconcentrationandcomposition。
3、Whytheresponsesofvariousnutrientstothechangesoftemperaturearedifferent?
4、Pleaseexplainthemechanismsofwaterstressordeficitonnutrientuptake?
5、Whennitrateisabsorbedbyroot,howthemediumpHwillchange?
Whatissituationofammoniumabsorption?
Pleaseexplainyouranswer.
NH4+-Ngenerallydecrease,NO3-Nincrease。
3NH4+3R.NH2+4H+,3NO3-3R.NH2+2OH-。
6、WhytheexcesssupplyofNH4+ionusuallyinducesthedeficiencyofK?
离子的竞争作用。
7、Whatistheionicantagonisms?
Andionicsynergism?
ionicantagonisms(竟争作用):
Oneionspeciespresentinexcessinthenutrientmediummaydepresstheuptakeofotherionspeciesiscalledionantagonism.指溶液中某一离子的存在能抑制另一离子吸收的现象。
ionicsynergism(协助作用):
Oneionspeciespresentinexcessinthenutrientmediummaypromotetheuptakeofotherionspeciesiscalledionsynergism.指溶液中某一离子的存在能促进另一离子吸收的现象。
第2章:
土壤-植物中的营养元素
Questions-9
1、Whichfactorsaffectthenutrientcontentsinsoils?
Climate、bioticactivities、topography(地形)、parentmaterial(母质)、time、ertilization(施肥)andcultivation(种植)。
2、Explaintheformsofnutrientsexistinginsoil.
(1)Bytheirphysicalstates:
Solidform、Liquidform、Gaseousform。
(2)Bytheirchemicalforms:
Organicform、inorganicform、Ionicform、Molecularform。
3、Defineavailablenutrientsinsoil
Theportionofanyelementorcompoundinthesoilthatcanbereadilyabsorbedandassimilatedbygrowingplants.在作物生长期间可供作物吸收利用的那一部分土壤养分称为土壤有效养分。
4、Whatfactorsinfluencediffusionofnutrientionstorootsinsoil?
Describeandexplainapracticalwayofimprovingthediffusionofnutrientions.
数量:
与土壤水分含量及养分浓度有关;养分种类:
土壤溶液中含量低的养分,如NH4,K+,PO4,Mg等。
由于养分浓度差的存在,导致养分由高浓度向低浓度的迁移过程,称为扩散。
提高土壤中的养分浓度可以促进扩散。
5、Explainthemechanismsofwaterstressonnutrientavailability.
6、Whatisyouropinionastotherelativeimportanceofrootinterception,simplediffusion,andmassflowinbringingnutrientionsintocontactwiththeabsorbingsurfaceofplantroots?
Wouldtheimportanceofthesethreemechanismsbealteredbysoiltexture?
Byplantspecies?
Why?
7、Definethefollowingterms:
nutrientavailability,massflow,diffusion,Q/Icurve,buffercapacity
nutrientavailability:
土壤全量养分中仅有一部分养分可以为作物吸收利用,这一特性称为土壤养分有效性。
massflow:
Massflowisthemovementofnutrientsthroughthesoiltotherootintheconvective对流flowofwatercausedbyplantwaterabsorption.指由于植物根系吸收水分引起的水流携带的养分由土体向根表的迁移现象。
Diffusion:
Whenaconcentrationgradientexist,netmovementoccursbydiffusionfromlocationsofhighconcentrationtolocationsoflowconcentration.由于养分浓度差的存在,导致养分由高浓度向低浓度的迁移过程,称为扩散。
Intensityfactor(I):
Whichisdirectlyavailableandrepresented代表bytheconcentrationofthesoilsolution.强度因素:
土壤对养分的保持能力,一般以土壤溶液中养分浓度作为衡量指标。
Quantityfactor(Q):
Whichrepresentstheamountsofapotential潜在availablenutrient.
容量因素:
土壤中有效养分的数量
buffercapacity缓冲力:
Theabilityofthesoiltomaintainthenutrientintensity,i.e.,thenutrientconcentrationinthesoilsolution.B=△Q/△I
Questions-10
1、Definetherhizosphere,rootexudation,allelopathy,mycorrhizae菌根
Rhizosphere:
Thispartofthesoil,whichisdirectlyinfluencedbytheroots,iscalledrhizosphereandextendsabout1to2mmfromtherootsurfaceintothebulksoil(Mengel,1987,pp-86).由于受植物根系活动影响在物理、化学和生物学性质上不同于土体的那一部分微域土壤称为根际。
或根际是根系周围受根系直接影响的那一部分微域土壤。
rootexudation根系分泌物:
根系生长过程中向生长介质中主动或被动地释放不同类型物质(包括根系脱落物)的现象。
allelopathy:
一些植物的根系分泌物也会对其他植物或其自身产生不良影响,即化学互感作用(Allelopathy)
mycorrhizae菌根:
heassociation,usuallysymbiotic共生,offungi真菌withrootsofseedplants.
2、Whatfactorsresultinthedifferencesbetweentherhizosphereandbulksoil?
Ion