局部根区水分胁迫下氮对玉米生长的影响

通过分根培养的方法,用聚乙二醇(PEG6000)模拟水分胁迫,研究3种氮形态(NO3- -N,NH4+-N,50% NO3- -N+50%NH4+ -N)及其供应部位对局部根区水分胁迫下玉米生长的影响.水分胁迫处理16d后,测定叶绿素荧光参数及茎、叶、根形态指标.结果发现,同一氮形态下,水氮同区处理(氮供应在非水分胁迫...     

GROWTH,NUTRIENT ACQUISITION,AND PHYSIOLOGICAL RESPONSES OF HYDROPONIC GROWN TOMATO TO SODIUM CHLORIDE SALT INDUCED STRESS

□ Growth and nutrient acquisition of tomato (Lycopersicon esculentum L.) cv ‘Amani’ were studied under induced salt stress in Hoagland's solution. The plants were treated for 37 days with salinity induced by incorporating different concentrations [0.0 (control), 50, 100, 150, or 200 mM] of sodium chloride (NaCl) to the nutrient solution. Slight reduction was obtained in growth represented by (shoot length and number, leaf number, and dry weight) when seedlings were directly exposed to NaCl stress from 0.0 to 100 mM. At higher concentrations (150 or 200 mM), growth parameters were adversely affected and seedlings died thereafter. Elevated salinity significantly reduced crude protein and fiber in shoots and roots. Tomato shoot and root contents of potassium (K), iron (Fe), and ash were reduced significantly in response to increased levels of salinity. Tissue contents of sodium (Na) and chloride (Cl) increased with elevated salinity treatments.     

EFFECT OF BICARBONATE ON GROWTH AND IRON NUTRITION OF PEA

ABSTRACT

Two cultivars of pea with different sensitivity to bicarbonate (Merveille de Kelvedon, tolerant and PS210713, sensitive) were cultivated during one month on a nutrient solution containing or not bicarbonate (10 mM). The study indicated that bicarbonate increased the root to shoot ratio much more in the sensitive than in the tolerant one. Bicarbonate reduced iron translocation towards shoots of the two cultivars. This effect was more marked in the sensitive one. The study also showed that bicarbonate provoked a considerable accumulation of iron in roots of the two cultivars. This accumulation was due to iron accumulated in the extraplasm of roots.     

保护性施氮对大豆氮素同化影响的研究

通过高Ｃ／Ｎ比值麦秸的“氮因子效应”调控土壤（肥料）氮固定－矿化动态作为大豆保护性施氮的手段。从大豆结瘤,固氮活性,木质部溶质氮形态以及植株同化氮量论证了保护性施氮的生物学效应。试验表明,保护性施氮不仅颇大缓解乃至完全消除了氮肥对大豆结瘤和固搂活性的抑制,提高了木质部中酰脲态氮的相对丰度和有机态氮含量,保护了共生固氮体系正常发育及其功能发挥的前提下,又提高了土壤的供氮水平,从而为大豆籽实蛋白质的合     

正常和高铵条件下氯化钠对万寿菊生长、开花和代谢的影响

在温室中以养分平衡的肥料组合和含250mg/L NH_4~+的组合栽培万寿菊(Tagetes patula L.)。每种组合中以一半植株每天每盆加250 mL 27.5 mmol/L NaCl溶液,进行盐胁迫处理。盐处理结果,使每株鲜重、株高和开花数都减少。盐处理2周后,根、叶细胞膜相对透性显著增加,叶子热处理渗出物中游离NH_4~+、根渗出物中Na~+。以及叶子中的过氧化物酶、Mg~(2+)-ATP酶和Ca~(2+)-ATP酶活性都明显提高,而根、叶渗出液的pH和蛋白质含量显著降低。根渗出物中游离NH_4~+、K~+和Ca~(2+)含量,叶子中叶绿素、可溶性蛋白质、无机磷和多酚氧化酶活性也下降,但未发现叶子渗出物中Na~+有所增加。在正常营养条件下,盐胁迫对叶子中的类胡萝卜素和花青素影响较小,但高NH_4~+处理使这些色素含量显著降低。高NH_4~+一般使NaCl的效应加剧。     

平流层辐射对谷子生长发育及后代性状的影响

平流层辐射对谷子的营养生长及后代性状的变异有显著影响。试验结果表明:经高空气球搭载的谷子,种子发芽势比对照提高21.1％,株高比对照降低6.8cm。叶片长度的生长动态呈双峰曲线,叶片长度和宽度与对照的差值由下到上呈正弦曲线,旗叶的面积、穗重均明显高于对照。SP_2分离群体中产生了各种各样具有隐性性状的突变体,SP_3大穗型株系性状相对稳定,在穗长、穗重、种子蛋白质含量和脂肪含量上表现出有选育价值的稳定变异。     

EFFECT OF NITROGEN APPLICATION ON GROWTH PARAMETERS,YIELD AND LEAF NITRATE CONTENT OF GREENHOUSE LETTUCE CULTIVATED DURING THREE SEASONS

Lettuce (Lactuca sativa L., cv. ‘Parris Island’) was grown hydroponically in autumn, winter and spring under five levels of nitrogen (N) fertilization. Plant biomass was highest in spring and lowest in autumn at N rates of 200 and 260 mg L^?1, respectively. Increasing N application correlated positively with rates of photosynthesis, transpiration, stomatal carbon dioxide (CO₂) conductance and leaf chlorophyll concentration. Photosynthetic rate, stomatal CO₂ conductance, and chlorophyll a/b ratio were higher in spring than in autumn or winter. Nitrate concentrations within the leaves increased with increasing N application in all seasons. It is concluded that lettuce growth and yield is higher in spring than in winter or autumn due to enhanced photosynthesis thanks to increasingly favorable photoperiod. Regardless of season, high N rates promote yield but increase leaf nitrate concentrations. Therefore, for the production of healthy produce the recommended N rate should be based not just on yield but also on the nitrate content.     

钾素营养对水稻根系生长和养分吸收的影响

本文研究了大田和盆栽试验中钾素营养对水稻根系形态、活力及其对养分吸收的影响。试验结果表明：（１）在氮磷肥的基础上施钾能促进稻根的生长；（２）土壤供钾潜力、钾肥种类和水稻品种的吸Ｋ特性均影响根系的生长；（３）在缺钾的酸性土壤上，吸钾强的品种，施钾的促根效应最为明显；（４）施钾能增加小于０．２ｍｍ的细根量，提高稻根的再生能力，影响Ｎ、Ｐ、Ｋ、Ｃａ、Ｍｇ等营养元素的吸收及其在地上和地下部分间的分配；（５     

盐胁迫和AM真菌对生菜生长的效应

试验设不接种、接种Glomus intraradices（BEG141）、接种Glomus mosseae（BEG167）3个接种处理，每个接种处理下再设电导率（EC）为607μScm^-1（低盐）、1236μScm^-1（中盐）、1866μScm^-1（高盐）等3个不同盐水平处理。试验结果表明：随着土壤EC值的增加，生菜生物量降低，但在低盐胁迫下，非菌根植株降低幅度大于菌根植株。与不接种处理相比，在低盐和中盐条件下，接种菌根真菌的植株体内NO3^-含量、植株地上部干重增加；同一土壤盐水平下，接种处理的植株磷、叶绿素含量高于不接种处理的；在低盐下，接种处理的植株的根系可溶性糖含量高于不接种处理的，但在1236和1866μScm^-1的盐度下，接种处理的植株根系可溶性糖含量低于不接种处理的。说明在施肥过量引起的次生盐渍化土壤中，AM真菌侵染对生菜在低盐胁迫下的生长存在促进作用，而在高盐胁迫下，使其生长受到抑制。     

矿质营养对绿萍生长的影响

近年来,稻田养萍在我国福建、浙江、广东、广西及江苏等省发展很快,并已在中、晚稻田中获得了养萍成功经验.但养萍过程中的施肥技术,至今尚未得到很好的解决.本文试图探讨绿萍生长与矿质营养的关系,以便为其合理施肥提供根据.     

硅氮磷颗粒肥对水稻吸收NP的影响

利用~(15)N、~(32)P示踪研究硅氮磷颗粒肥对水稻吸收利用NP影响结果表明,硅氮磷颗粒肥对促进水稻生长发育、增蘖、增穗有明显作用。插秧时施用,稻谷平均增产18.4％。水稻植株体内积累总N量比不施硅氮磷颗粒肥的高11.45％,全磷高12.1％。水稻植株对肥料N、P利用率分别提高7.7％和3.4％。     

施肥对大白菜中氮同位素及硝酸盐含量的影响

研究不同肥料配施处理对土壤和大白菜中稳定性氮同位素丰度(δ15 N‰)及硝酸盐含量的影响.结果表明,随着有机肥比例的降低,大白菜中δ15 N和硝酸盐含量分别呈现逐渐降低和增加的趋势,对照大白菜中δ15 N和硝酸盐含量分别为+9.355‰和1459mg/kg;纯有机肥(100%-O)和纯化肥(100%-C)处理大白菜中δ...     

氮锌硒肥配合施用对黑麦草锌营养的影响

本文研究在湖北省宜昌县山地黄棕壤上以磷肥为底肥单施锌、硒肥及氮锌硒肥配合施用对单播与混播黑麦草中锌营养状况的影响。试验结果表明 :单施锌肥明显增加混播黑麦草 (混播比例为白三叶∶黑麦草为 1∶4)中的锌含量 ,且随施锌量的增加 ,混播黑麦草中的锌含量也增加 ;单施磷肥的处理与不施肥的对照相比较 ,混播黑麦草中的锌含量降低 ,其主要原因是干物质量增加引起的稀释效应。单施硒肥情况下 ,混播黑麦草中的锌含量随着施硒量的增加呈降低趋势。氮锌硒肥配合施用的 9个处理中 ,混播黑麦草中锌含量最高的处理是N46Zn2 5Se1 ;单播黑麦草中锌含量最高的处理是N30Zn2 5Se5。     

COMPARATIVE STUDY OF DIFFERENT SALTS (SODIUM CHLORIDE,SODIUM SULFATE,POTASSIUM CHLORIDE,AND POTASSIUM SULFATE) ON GROWTH OF FORAGE SPECIES

Osmotic and specific ion effects are the most frequently mentioned mechanisms by which saline substance reduces plant growth. However, the relative importance of osmotic and specific ion effect on plant growth seems to vary depending on the salt tolerance of the plant under study. Tall wheatgrass (TW), perennial ryegrass (PR), African millet (AM) and Rhodesgrass (Rh) were grown in nutrient solution with sodium chloride (NaCl), sodium sulfate (Na₂SO₄), potassium chloride (KCl), and potassium sulfate (K₂SO₄) salinity up to electrical conductivity (EC) 27 dS m^?1. Growth of all plant species decreased significantly at high level (EC 27 dS m^?1) of NaCl and Na₂SO₄ salts. However, the growth of none of the plant species was affected significantly by KCl and K₂SO₄ at any level. Even leaf and shoot fresh weights were enhanced by K₂SO₄ in all plant species, except AM. Chlorine (Cl) was taken up in similar quantities from KCl and NaCl solutions and the content of the respective cations was similar to each other. Further sensitivity to sulfate and chloride was equal when sodium concentrations in shoots were equal, regardless of the anion composition of the media. The sodium (Na) concentration of the leaves of the plant species increased with increased NaCl and Na₂SO₄ levels in the nutrient solutions. The leaf Na concentration of TW was lower than that of the other plant species. However, the root Na concentration of TW was higher than that of the other plant species. Increased NaCl and Na₂SO₄ concentrations had a marked effect on leaf water potential of all plant species, and the TW showed higher leaf water potential at all levels of salts. Tall wheatgrass adjusted osmotically by accumulating electrolytes from the nutrient solution and by accumulation of glycinebetaine. Sodium was generally found more injurious than Chloride in all the four forage species. Salt tolerance could be ascribed as greater exclusion of Na ion.     

模拟酸雨胁迫对菠菜中草酸积累及营养品质的影响

在田间试验条件下,研究了模拟酸雨胁迫对菠菜中草酸积累及相关营养品质的影响,旨在为优质蔬菜生产提供一定的理论依据。结果表明,经酸雨胁迫处理后菠菜根、叶柄和叶片等器官中草酸的积累量均明显增加,并与酸雨pH值呈显著负相关(r =-0.93*、-0.88*、-0.86*),同对照相比,pH5.0,pH4.0和pH3.0处理增幅分别高达81.2%、147.8%和158.5%;菠菜中蛋白质、游离氨基酸、可溶性糖、Vc等营养成分的含量随着酸雨pH值的减小而逐渐降低,其降幅可分别高达44.98%、64.58%、44.98%和63.23%,不同pH模拟酸雨胁迫下多种营养成分含量的差异达到极显著水平(P< 0.01)。酸雨胁迫会导致菠菜营养及卫生品质劣变。     

渍水对小麦氮磷钾营养效应的研究

渍害是我国小麦生产的主要自然灾害之一,严重影响到小麦产量.其原因可能是渍水使得土壤氧亏缺,抑制了作物的生理代谢,改变了植物营养状况和土壤养分的有效性;或是由于较低的土壤氧化还原电位使得营养的吸收与累积下降[1～3].     

PHYTOTOXICITY OF SALTS IN COMPOSTED SEWAGE SLUDGE AND CORRELATION WITH SODIUM CHLORIDE,CALCIUM NITRATE,AND MAGNESIUM NITRATE

The phytotoxicity of salts in composted sewage sludge (CSS) was evaluated. Concentrations of sodium (Na⁺), chloride (Cl^?1), calcium (Ca²⁺), and magnesium (Mg²⁺) were present at levels that would induce salt stress in plants. Nutrient imbalances were also found that would adversely affect the use of CSS as a growth medium. To further understand the phytotoxic nature of these salts, sodium chloride (NaCl), calcium nitrate [Ca(NO₃)₂] and magnesium nitrate [Mg(NO₃)₂] solutions were used to simulate the composition of salts found in CSS in an investigation of radish (Raphanus sativus L.) seed germination. High concentrations of Ca²⁺ (92.1 mmol.L^?1) and Mg²⁺ (27.4 mmol.L^?1) inhibited seed germination to an equal extent as did Na⁺ (40.6 mmol.L^?1). The lower concentration of Ca²⁺ (10 mmol.L^?1), however, significantly relieved the stress caused by NaCl. These results indicated that the composition and total amount of Na⁺, Cl^?1, Ca²⁺, and Mg²⁺ in CSS should be carefully monitored before it is used as a soil amendment or growth medium.     

紫色土施氮对莴笋营养效应的研究

3种紫色土施用化学氮肥盆栽莴笋的研究结果表明,石灰性紫色土莴笋生长状况最差,施中、高氮明显降低其株高、根重和茎、叶产量,而中性紫色土施氮的生物效应最佳。酸性紫色土莴笋叶片((NO3--N)/(TN)100)值最低、((AAN)/(TN)100)值最高;植株氮素表观利用率为中性土酸性土石灰性紫色土。中性、酸性和石灰性紫色土施氮分别为133、67、67mg/kg土时,莴笋3个生长期叶片N/P、N/K、K/P值变异系数(C.V％)小,生物量高。施氮显著提高中性和石灰性紫色土莴笋叶片NRA(r值0.9275*～0.9956* *),降低CAT活性和Vc含量,使茎中(△NO3-)/(△FN)值高于酸性紫色土2～5倍,但却提高酸性紫色土莴笋水溶性氨基酸、粗蛋白和可溶性糖含量,改善其食用价值。