植物营养学复习要点

1、植物营养学复习要点 第一章： Questions-2 1、How to assess 评价 an element that is essential to higher plants? （1) A given plant must be unable to complete its life cycle in the absence of the mineral element; （2) The function of the element must not be replaceable by another mineral element; （3) The element must be

2、directly involved in plant metabolism- for example, as a component of an essential plant constituent such as an enzyme- or it must be required for a distinct metabolic step such as an enzyme reaction. 2、How many kinds of elements are essential for higher plants? 18 3、What are the general functions o

3、f the essential elements for higher plants? As the constituents 成分 of important compounds in plant； As the constituents or activators of enzymes 作为酶的成分或激活剂 Stabilize the structure of the cell 4、Please describe the general composition of a living plant. Water、Dry matter（Organic matter and ashes/ mine

4、rals ) 5、Terms:Hyperaccumulation,phytoremediation,Macronutrients,micronutrients,three essentials of fertilizer Macronutrients：C,H,O,N,P,K,Ca,Mg,S。 Micronutrients：Cu,Zn,Mn,Fe,B,Mo,CI,Ni，Co。 Questions-3 1、What are the main functions of plant roots? Anchoring 固定 the plant in the soil Absorption and tra

5、nslocation of water and nutrients Synthesis of phytohormones 植物激素 and other organic compounds Storage 存储 of inorganic and organic nutrients 2、There are two kinds of roots, what are they?须根系（fibrous root system） 、直根系(tap root system） 3、Whats root hair? Cluster root?群集根 root hair：Root hairs are tubula

6、r 管状物的 tensions of the root epidermal 表皮 cell and occur as a result of lateral cell growth. Cluster root： 4、There are many environmental factors that affect root growth. What are they? How they affect the growth of root? Soil compaction：土壤容重 1.1-1.3 g/cm3 适宜旱地作物生长。 溶液中根系细长，土壤中根系粗短。 Soil temperature：

7、适宜温度：20-25 Water：“干长根，湿长苗” Nutrient：根系具有趋肥性 Questions-4 1、How many parts of a root tip could be divided into? Meristematic zone 分生区、Elongation zone 伸长区、Hair zone 根冠。 2、Please describe the transverse section 截面 of a young root Root hairs/根毛、Epidermis/表皮、Parenchyma/皮层薄壁组织、Endodermis/内皮层、Stele/中柱。 s fr

8、ee space in a root? Donnan free space and water free space? What、3free space：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、What are apoplast and symplast? Symplast：the cytoplasmatic continuum formed by numerous plasmodesmata. 共质体：指各个活的细胞通过胞间连丝相互连在

9、一起形成的统一体 Apoplast ：comprises all parts of the tissue open to solutes and water without their having to cross a membrane.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、Please describe the structure of a cell membrane. 大约等比例的蛋白质和脂质分子组成，约 7 to 10 nm 厚。 Questions-5Questions-5 1、What is active and passive

10、absorption of elements by plant root cells? passive uptake:顺浓度或电化学梯度、不消耗能量、无选择性。 active uptake ：逆浓度或电化学梯度、消耗能量、有选择性。 2、What is ion pumps, ion channels? ion channels：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。 ion pumps： 3、Why Nernst Equation is useful for interpreting 解释 the ion transport into plasma 原

11、生质 membrane? 4、What, generally, is the mechanism that has been proposed to account for the active absorption of ions by roots? 载体学说 (Carrier transport)、离子泵学说 (Ion pump) 5、Is the driving force the same for charged nutrients and uncharged nutrients across the membrane? Explain your answer. Uncharged m

12、olecules 不带电的 move in response to: differences in concentration(chemical gradient) Charged molecules move in response to:differences in concentration (chemical gradient)、differences in voltage(electrical gradient)= electro-chemical gradient 6、Please describe the types of transporters existed in the

13、membranes. 主动运输、被动扩散、内吞外排。 7、Km, Cmin, Imax Imax: maximal net influx of ions into roots 离子进入根的最大量 Km: Michaelis-Menten constant 米氏常数 Cmin: Concentration of nutrient in medium 养分介质中的浓度 when influx=efflux 当进出相等 Questions-6Questions-6 1、What is foliar fertilization? The process of nutrient uptake by le

14、aves and other aerial plant organs(也称为根外营养). 2、What are the advantages and disadvantages of foliar fertilization? Advantages：Preventing the fixation or transformation of nutrients or plant growth regulators in soils 防止养分在土壤中固定和转移。 High uptake rate and immediately involving plant metabolism 吸收速度快而且立即

15、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、How to increase the uptake efficiency of nutrients applied by foliar spraying? Nutrient species； Concentration and pH of nutrients；Wetting time 润湿时间；Leaf type；Mobility of nutrient in plant Questions-7Questions-7 1、Why the o

16、ccurrence of calcium deficiency is usually observed in some plants grown in calcareous soil? 2、Why the earliest visible deficiency symptoms of N, P and K appear in the older leaves of plants? Ca, Fe, Zn, et. al deficiency symptoms appear in younger leaves? N, P and K 在植物体可移动；Ca, Fe, Zn, 在植物体不可移动。 3、

17、Why boron toxicity of plant is usually observed in the margins of older leaves when the concentration of boron in soil is very high? 4、Please compare the short distance transport and long distance transport of nutrient in plant. short distance transport：Pathway：apoplast（质外体） 、symplast（共质体） ong dista

18、nce transport：Pathway：xylem zailem木质部、phloem fl?uem 韧皮部。 5、Which kinds of nutrients are mainly transported in apoplastin plant? Which nutrients in symplast? 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: Short distance transport; long distance transport ； nutr

19、ient remobilization; nutrient cycling and recycling in plant Short distance transport：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。 long distance transport：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。 nutrient remobilization：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：The retranslocation of nutrients in the phloem

20、 from the shoots to the root. 养分由根木质部地上部分韧皮部根的循环过程。 Recycling（再循环）：The translocation 运输 of cycled nutrients back in the xylem to the shoots. Questions-8Questions-8 1、In the growth period of a plant, there usually have several key periods for nutrient uptake, which are very important for plant growth

21、. Please name them. 植物营养临界期 (Critical period of plant nutrition)； 植物营养的最大效率期(Maximum efficiency stage of plant nutrition) 2、There are many environmental factors influencing ion absorption of root. What are they? Light、temperature、water、pH、aeration 通气性、nutrient concentration and composition。 3、Why th

22、e responses of various nutrients to the changes of temperature are different? 4、Please explain the mechanisms of water stress or deficit on nutrient uptake? 5、When nitrate is absorbed by root, how the medium pH will change? What is situation of ammonium absorption? Please explain your answer. - 3R.N

23、H 3NO + 4H+ 3R.NH3NHNO3-N increase NH4+-N generally decrease， 。+ ， 。 + 2OH-23246、Why the excess supply of NH4+ ion usually induces the deficiency of K? 离子的竞争作用。 7、What is the ionic antagonisms? And ionic synergism? ionic antagonisms（竟争作用）：One ion species present in excess in the nutrient medium may

24、depress the uptake of other ion species is called ion antagonism.指溶液中某一离子的存在能抑制另一离子吸收的现象。 ionic synergism（协助作用）：One ion species present in excess in the nutrient medium may promote the uptake of other ion species is called ion synergism.指溶液中某一离子的存在能促进另一离子吸收的现象。 第二章第二章 ：土壤：土壤- -植物中的营养元素植物中的营养元素 Quest

25、ions-9 1、Which factors affect the nutrient contents in soils? Climate、 biotic activities、topography(地形)、parent material（母质） 、time、ertilization(施肥) and cultivation(种植)。 2、Explain the forms of nutrients existing in soil. (1) By their physical states：Solid form、Liquid form、 Gaseous form。 (2) By their c

26、hemical forms：Organic form、inorganic form、Ionic form、Molecular form。 3、Define available nutrients in soil The portion of any element or compound in the soil that can be readily absorbed and assimilated by growing plants.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、What factors influence diffusion of nutrient

27、 ions to roots in soil? Describe and explain a practical way of improving the diffusion of nutrient ions. 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+, PO，Mg 等。 4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、Explain the mechanisms of water stress on nutrient availability. 6、What is your opini

28、on as to the relative importance of root interception, simple diffusion, and mass flow in bringing nutrient ions into contact with the absorbing surface of plant roots? Would the importance of these three mechanisms be altered by soil texture? By plant species? Why? 7、Define the following terms: nut

29、rient availability, mass flow, diffusion, Q/I curve, buffer capacity nutrient availability：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。 mass flow：Mass flow is the movement of nutrients through the soil to the root in the convective 对流 flow of water caused by plant water absorption.指由于植物根系吸收水分引起的水流携带的养分由土体

30、向根表的迁移现象。 Diffusion：When a concentration gradient exist, net movement occurs by diffusion from locations of high concentration to locations of low concentration.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。 Intensity factor (I)：Which is directly available and represented 代表 by the concentration of the soil sol

31、ution.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。 Quantity factor (Q)：Which represents the amounts of a potential 潜在 available nutrient. 容量因素：土壤中有效养分的数量 buffer capacity 缓冲力：The ability of the soil to maintain the nutrient intensity, i.e., the nutrient I Q/concentration in the soil solution.B =Questions-10 1

32、、Define the rhizosphere, root exudation, allelopathy, mycorrhizae 菌根 Rhizosphere：This part of the soil, which is directly influenced by the roots, is called rhizosphere and extends about 1 to 2 mm from the root surface into the bulk soil (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

33、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。 root exudation 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：he association, usually symbiotic 共生, of fungi 真菌 with roots of seed plants. 2、What factors result in the differences between the rh

34、izosphere and bulk soil? Ion concentration、pH、Redox (Eh)、Root exudation（根系分泌物） 3、Is the concentrations of the ions in rhizosphere always lower than that in the bulk soil? NO。 4、What factors induce the pH change in rhizosphere? mbalance uptake of cations and anion ions，阳离子和阴离子的不平衡吸收 N-fixation by leg

35、uminous crops（NH4+, H+） ，豆科作物 N-固定 soil respiration（CO2） ，土壤的呼吸作用 exudation of organic acids，有机酸的分泌物 nutrient stresses（FeH+, Porganic acids） 5、Describe the possible compositions of root exudates. Gas（CO,CH） ； Proton and inorganic ions 质子和无机离子；Organic matters。 2226、Explain the potential roles of root

36、 exudates in plant nutrition. influence nutrient availability in soil by the changes of pH, Eh, or chelating; 通过改变根际 pH、Eh、或螯合作用等，影响养分的有效性； root exudates absorbed by other plants directly;分泌物可以直接为其他植物吸收利用； root exudates inhibit the growth of other plants（allelopathy）.分泌物的抑制作用，即化学互感作用 7、Explain the n

37、ecessary to study the rhizosphere. Questions-11 1、Explain the potential gains and losses of the nutrients in agricultural soils. 2、Describe the methods of applying the fertilizers. What are the advantages and drawbacks of each method? Soil application、 Foliar application 3、What are the consequences

38、of inadequate application of fertilizer on the environment? 硝酸盐的淋失（NO3 leaching） ；水体富营养化 （Eutrophication） ；温室效应（Greenhouse effect） ；臭氧层的破坏(Destruction of stratospheric ozone)；生物多样性的降低（Decrease of biodiversity） 。 4、Define the fertilizers, straight fertilizers, and compound or mixed fertilizer, fertil

39、izer grade, eutrophication. ertilizers：Any material, except lime, added to soil to supply one or more essential elements.凡是施入土壤中能够为作物供应养分，改善和提高土壤肥力的物料均可称为肥料。 Eutrophication：Enrichment of waters with nutrients, primarily phosphorus, causing abundant aquatic 水体的 plant growth. fertilizer a in nutrients

40、 available the of percentage guaranteed minimum The 肥料级：gradefertilizer (in the forms of N, P2O5 and K2O for N, P and K, respectively). 最小保证肥料中的养分的百分比。 第三章：植物氮素营养与氮肥 Questions-12Questions-12 1、Why nitrogen is so important for plants? its important role in the growth of plant ； N deficiency in soil i

41、s very common -+2、What are the main forms of nitrogen uptake by plants? Mainly as the forms of NO-N,NH-N. 433、Describe the basic reduction processes of nitrate in plant. -+ NONONHNitrate reductase（硝酸还原酶）和 Nitrite reductase（亚硝酸还原酶）的作用423 下。4、What factors affect the contents of nitrate in plants? Depe

42、nd on plant species, growth periods, and parts of plant, and fertilization, etc. 5、Describe the assimilating processes of ammonium in plant. NH+Oxo acid（酮酸）Amino acids（氨基酸） 36、Compare the nutrition of nitrate and ammonium for plants. 供应硝态氮促进了植物体内有机酸累积； 供应不同形态氮素对生长介质 pH 值的影响：供应硝态 N 使 PH 升高，供应铵态 N 使 P

43、H 降低，两者适当比例最佳。 7、Describe the symptoms of nitrogen deficiency of plants, and harmful effects of over-application of nitrogen fertilizer. (1) Nitrogen deficiency symptoms Yellowing of older leaves (chlorosis)； Stunted growth 发育迟缓； Showing deficiency symptoms in the older leaves (2) Symptoms of excess

44、ive supply of N With crops such as cotton, a weakening of the fiber 纤维素 may result. With grain crops, lodging may occur; Excessive nitrogen fertilization will also reduce the sugar contents of sugar beets； may make a plant more susceptible (易受影响)to disease or insect attack; Questions-13Questions-13

45、1、What are the main forms of nitrogen existed in soils? Organic N（ 95%） 2、Compare the occurring conditions of ammonification, nitrification, denitrification in soils. Ammonification ：can occur in aerobic 有氧 or anaerobic 厌氧 conditions due to the various microbes involved in the process.有氧或无氧、多种微生物。 N

46、itrification：有氧、硝化细菌和亚硝化细菌。 Denitrification：厌氧、反硝化细菌。 3、What are the main pathways of nitrogen losses from plant-soil system? NH3-volatilization （氨的挥发作用） 、 Leaching（淋溶作用） 、 Denitrification（反硝化作用） 。 4、Describe the consequences of nitrogen loss to the quality of environment. NO 是温室效应气体，可破坏臭氧层 2-5、What

47、 conditions favor NO accumulation? 2Alkalinity of soil（碱性土壤） 、High ammonium levels（铵的浓度高） 。 6、Define ammonification, Nitrification, denitrification, reactive N. +Ammonification：soil organic N 转化成 NH 的过程。 4Nitrification:the biological oxidation of ammonium salts to nitrites and the further oxidation

48、of nitrites to nitrates.铵盐生物氧化生成亚硝酸盐和亚硝酸盐进一步氧化生成硝酸盐。 Denitrification:the biochemical reduction of nitrate or nitrite to gaseous nitrogen, either as molecular nitrogen or as an oxide of nitrogen.硝酸盐或亚硝酸盐经生化反应生成气态的、分子或氮的氧化物。 +reactive N ：NH, NH, NO, NO, NO, NO, NO, NO。 （易反应的 N） 5 32422-23-Questions-14

49、Questions-14 1、What are the three basic processes for the fixation of elemental nitrogen used in fertilizer manufacture? Direct oxidation of nitrogen；The cyanamide process(氰氨法)；The synthesis ammonia process 铵的合成。 2、Classify the various forms of nitrogen fertilizers. Ammoniacal fertilizers（铵态氮肥） 、Nit

50、rate fertilizers（硝态氮肥） 、Slowly available fertilizers 缓释型肥、Others。 3、What is the commercial nitrogen fertilizer with the highest percentage of nitrogen? What solid nitrogenous material has the highest percentage of nitrogen? Anhydrous ammonia（无水氨） ；Urea（CO(NH)尿素） 224、What precaution 措施 should be obse

51、rved in applying ammoniacal nitrogen fertilizers to calcareous soils? 5、Why,specifically,have ammonia forms of nitrogen an acidifying 酸化 effect on the soil? 碳酸氢铵、碳酸铵，氯化铵。解离成离子，铵离子被作物吸收，残留酸根离子于土壤。 6、Why is it sometime unwise to apply urea to the surface of the soil? 7、What are the practical ways of i

52、mproving the agronomic 农艺 effectiveness of urea? 8、Describe the ideal sources of fertilizer nitrogen. What are the major approaches used for controlling nitrogen fertilizer availability? (N+H=NH) 322The technique of application of N fertilizers 、 Develop the suitable form of N fertilizer。Coated fert

53、ilizers (包裹肥料) 9、Define nitrification inhibitor, urease, urease inhibitor, controlled-release fertilizers. 第四章：植物磷素营养与磷肥 Questions-15Questions-15 1、What are the basic functions of P in plants? P and C-metabolism：Photosynthesis 光合作用、Synthesis of carbonhydrates 、 Translocation of photosynthates/carboh

54、ydrates、 Respiration 呼吸作用 P and N- metabolism：硝酸盐的转化、N 同化、豆科植物 N 的固定 P and 脂肪 Lipid-metabolism; Other functions of P in plant:Improving the stress resistances（抵抗力）of plants(抗旱、抗热、抗 PH） 2、What are the major roles of phytin （植素）in plants? Phytin is formed during seed formation（种子的形成过程中形成的植素）. P in phy

55、tin form in seed is regarded as a P reserve（储备）. During seed germination（萌芽） phytin P is mobilized （调动）and converted（改变） into other phosphate forms needed in the metabolism of young plants. Describe the possible role of P in N uptake and metabolic processes of plants. 、3 P 参与硝酸盐的转化、N 同化、豆科植物 N 的固定。

56、P 参与了转氨基作用，C 架的合成，氨基酸和蛋白质的合成。 4、What are the main forms of P uptake by plants?正磷酸盐 5、Describe the symptoms of P deficiency of plants. 植株矮小、直立 ，叶色暗绿或灰绿，症状首先从下部老叶表现出来 6、The yield of plant suffering from P deficiency is low, and quality is poor. Why? 因为 P 参与了作物的光合作用和蛋白质的合成，直接影响了作物的产量和质量。 Questions-16Qu

57、estions-16 1、Is organic P the major form of P existed in mineral soil? No，mineral soil：Mineral P（Organic P 占 10%-50%；Mineral P 占 50%-90% of total P in soil。 ） 2、How to divide or group the mineral P in soil? Fe 、Al 、Ca 的化合物 3、What are the various mechanisms of phosphate retention or fixation in acid

58、mineral soil? and in calcareous mineral soil? acid mineral soil：化学固定 calcareous mineral soil：mechanisms of phosphate retention（P 合成机理）：化学固定、吸附固定？闭蓄态固定？ 4、Is fixed phosphorus totally lost to plants? 5、What soil properties influence the retention or fixation of added fertilizer phosphorus? Types & com

59、position of clay、 Soil texture（土壤质地） 、pH、Eh、Soil moisture 水分、Others。 6、Explain why phosphorus is more available at pH 6-7 than at pH values of 4 or 8? PH 在 4 和 8 时 P 的固定最高，而 PH 在 67 时 P 的固定率低，有效性高。 Questions-17Questions-17 1、Are there enough phosphate rock reserves in China?磷矿储量 No，世界上，美国（30%） 、摩洛哥（

60、17%） 、中国（14%） 、俄罗斯等（1999 年） 。我国磷矿资源占有量居世界第三位位；磷肥产量已超过美国，居世界第一位。磷肥消费量居世界第一位，占世界总消费量的 29.7%。 2、What are the three basic processes for manufacturing the phosphorus fertilizers? Mechanical（机械法） 、Acid-treated 、Heat-treated 。 3、How to classify the various phosphorus fertilizers? P fertilizers are grouped