Nitrogenous constituents of bleeding sap from taro plants grown in nitrate nutrition under a potassium deficiency

The previous work (1) with bleeding sap from taro plants grown in solution culture at varying ammonium sulphate application under aerobic condition revealed that a potassium deficiency led to a contradictory relationship of the variation in amino-N content in bleeding sap to the exudation rhythm; in the earlier period of bleeding experiment a deficient K-application decreased the amino-N content but accelerated the exudation rate. In this connection, there are good reasons for believing that the passage of water and salts into the xylem ducts is largely controlled by the metabolic conditions in adjacent living cells, especially their rate of aerobic respiration (2). Therefore, the effects of potassium nutrition on the exudation phenomenon were reexamined with taro plants grown in solution culture under nitrate nutrition and correlated with information about the effect of aeration through culture medium during bleeding experiment on the rate of exudation and contents of nitrogenous constituents of bleeding sap. Arsenite- or DNP-treatment was also carried out in vivo with the roots in order to elucidate a possible relationship between the respiration in roots and the exudation process of xylem sap.     

不同供钾源及其用量对钾素营养的影响

以牛厩肥、猪厩肥、麦秸和钾化肥为供钾源 ,进行土培和生物试验 ,结果表明 ,麦秸对土壤的供钾能力及对作物的有效性均高于钾化肥 ,两种厩肥的供钾能力及生物有效性略低于钾化肥 .随着厩肥和麦秸施用量的增加 ,土壤速效钾和缓效钾基本是成比例的增加 ,钾素有效转化率并未因施用量提高而明显降低 .随着施用量的增加 ,玉米幼苗吸钾量呈增加趋势 .     

The respiration in leaf disks from younger taro plants under a moderate potassium deficiency

It has been reported that there is a considerable difference in the response of leaves and roots to K-deficiency (1), which may be due to the difference in the severity of the deficiency in the two tissues under the same K-application (2). The previous work (3) suggested that the metabolic disturbance induced by K-deficiency might depress preferentially the metabolism in roots rather than that in leaves. Another work with taro leaves in the later growth stage (4) suggested that any indirect metabolic disturbance caused by an extended K-deficiency might result in a depressed operation of the TCA cycle. The bleeding experiments with taro plants in the earlier growth stage (5) showed that arseniteand DNP-treatment in vivo with the roots, both reduced significantly the release rate of nitrogenous constituents and water with bleeding sap. Based on these informations, the growth and the respiration of leaves under a moderate K-deficiency were re-examined with younger taro plants in an attempt to compare them with those of the roots (4). At the conclusion of a series of studies on the nutritional physiology of taro plants, effects of Kdeficiency on the metabolic activities of the plants are discussed in special relation to the mitochondrial respiration.     

Effects of potassium nutrition on the absorption of sodium,calcium, and magnesium by intact tomato plants

Abstract

Tomato plants (cv. VF145 B 7879) were grown in a greenhouse by the water culture technique with six levels of K nutrition. The absorptions of Na, Ca, and Mg were not affected greatly by the K nutritional status of the intact tomato plants, except when the plants were extremely K deficient. The rates of absorption by the intact plants were slow initially when the plants were small, and then increased rapidly as the growth rates increased.

At the onset of K deficiency, the rate of growth and water use by the tomato plant decreased. A linear function of water use and plant size was obtained, indicating that water use was a function of plant size and hence a function of the plant's nutritional status.

Waterlogging, simulated by aeration cut‐off of the culture solution for two days, had only a small effect on water use, but concurrently interrupted the absorption of K, Ca, and Mg.     

氮钾配施对芋头产量和品质的影响

采用二次饱和D-最优设计,研究了氮钾肥配施对芋头产量和品质的影响,并建立了以氮、钾肥施用量为变量因子,芋头产量和品质为目标函数的二元二次数学模型。模型解析表明,氮、钾肥对芋头产量和品质均有显著影响,且钾肥的影响大于氮肥;氮、钾肥之间存在显著的交互效应。在氮(N)、钾(K2O)施用量分别为261.75kg/hm2、757.50kg/hm2以内,产量随施肥量的增加逐渐提高,超过此施用量,则产量下降。在本试验条件下,施肥量为N34.5～531.0kg/hm2,K2O.526.8～1057.2kg/hm2,芋头产量可达30000kg/hm2以上。     

钾对不同基因型玉米生长、体内钾循环和分配的影响

钾素循环和再利用对维持植物生长和提高钾利用效率非常重要。本文以杂交玉米豫玉23和兴农998为供试作物,采用供应高钾（1.85 mmol/L）和低钾（0.1 mmol/L）营养液的石英砂培养方法,研究不同基因型玉米各器官干重和钾积累及分配、 体内钾在木质部和韧皮部中的循环、 流动及钾效率等。结果表明,低钾处理10 d后,与高钾处理相比,低钾降低两玉米品种各器官干重净增量、 钾浓度、 钾积累量、 钾吸收效率和木质部中钾的运输量,增加钾利用效率和源叶中韧皮部输出的钾,提高钾通过韧皮部的再循环量及占木质部运输总量的比例。低钾处理的豫玉23和兴农998上部叶均为钾库,钾积累量的38.5%和70.3%是由各自中、 下部叶韧皮部输出的钾供给,但体内光合产物和钾向上部叶的运输是不完全同步的过程。两品种比较,低钾处理下的豫玉23较兴农998干重净增量提高,在于前者具有较大根量、 较高钾吸收速率和较多钾素吸收量,木质部中有更多的钾通过叶片韧皮部输出进行循环运输进入上部叶;但豫玉23对介质中钾的吸收大于体内钾的再利用。钾营养高效基因型玉米应该具有较强的吸收和利用体内钾的能力。     

芋对氮磷钾吸收分配规律的研究

芋幼苗期对氮磷钾的吸收较少,发棵期和球茎膨大期吸收速率迅速增加,球茎膨大后期吸收积累速率又有所下降。总的来说,芋植株对钾的吸收最多,氮次之,磷最少,全生育期对氮磷钾的总吸收比例为1∶0.28∶1.1。幼苗期和发棵前期氮磷钾主要分布在叶片和叶柄中;其中,氮以叶片中居多,而磷和钾则以叶柄中居多。发棵后期和球茎膨大期主要分配在芋球茎中,其中氮磷的分配率为子芋大于孙芋,而钾则是孙芋中分配多于子芋。     

Effect of calcium/potassium ratio ammonium supply on nutrition and yields of cucumber plants

A greenhouse experiment was conducted in order to study the influence of two calcium/potassium (Ca/K) ratios (0.75 and 0.33) and ammonium supply (0 and 1 mmol/L) in the nutrient solution on nutrient uptake, mineral composition, and productivity of cucumber plants grown in sand culture. There were not significant differences in nitrate consumption between the four treatments. Calcium and potassium consumptions were directly related with the Ca/K ratio in the nutrient solution. The treatment with Ca/K = 0.75 and ammonium supply, that showed the lowest potassium and nitrogen plant levels and the highest calcium uptake and concentration in plant, offered the highest yields.     

同步营养肥对烟草产量和氮钾营养状况的效应

探究在我国南方多雨气候条件下,施用同步营养肥在烟草栽培中的应用效果,以期为烟草同步营养肥替代常规化肥提供理论依据。在湖南郴州2个自然村开展了2种主栽烤烟品种（云烟87和K326）的同步营养肥与常规肥大田肥效对比示范试验,共设2个处理,分别为同步营养肥减量25%(SNF25)和传统施肥（即常规肥不减量施用,CF）。通过观察烟草长势以及测定烟草农艺性状、产量及其构成因子和烟叶氮钾养分含量,以评估烟草同步营养肥的应用效果。结果表明：与CF比较,SNF25不影响烟草长势和中下部叶片叶色,但SPAD值明显增加,其中云烟87上部、中部和下部叶SPAD值分别增加了6.14%、10.14%和18.86%,而K326 3个部位的SPAD值则分别增加了6.88%、11.63%和15.93%。此外,SNF25不影响云烟87和K326的农艺性状,其中株高、叶片数、茎径和叶面积与CF均无显著差异。相对于CF,SNF25云烟87和K326单位面积烟叶鲜叶产量及干叶产量均无显著差异。SNF25和CF在单株叶鲜重和干重呈现相同的规律,其中中部叶鲜重和干重均为最大值,上部叶和下部叶次之,且2个处理上部、中部和下部叶鲜重...     

施肥对芋艿头产量和品质的影响

通过对奉化芋艿头的施肥试验 ,研究了施肥对芋艿产量和品质的影响。认为钾素和有机肥是影响奉化芋艿头产量和品质的主要因素。优质高产栽培技术应采用增施有机肥和氯磷钾结合的施肥方法     

不同供钾水平对西瓜幼苗生长和根系形态的影响

通过盆栽试验,研究5个供钾水平(0、60 kg.hm 2、240 kg.hm 2、500 kg.hm 2和700 kg.hm 2)下西瓜苗期生长指标和根系形态参数的变化。结果显示:240 kg.hm 2钾浓度下,西瓜幼苗茎鲜重、叶鲜重、茎干重、叶干重、子叶面积、茎粗、株高、根长、比根长、表面积、根体积、根尖数和根平均直径分别比不施钾处理增长46.05%、31.31%、57.56%、29.87%、2.92%、12.71%、37.18%、67.23%、64.00%、64.03%、58.88%、154.11%和6.25%。700 kg.hm 2钾浓度下,西瓜幼苗茎鲜重、叶鲜重、茎干重、叶干重、子叶面积、茎粗和株高比240kg.hm 2钾浓度处理分别降低40.24%、25.31%、36.90%、23.08%、31.09%、9.81%和41.44%。700 kg.hm 2钾肥处理对西瓜幼苗根系生长的抑制作用不明显。所有处理的西瓜幼苗直径≤1.0 mm的根长占总量的90%以上,直径≤0.5 mm的根尖数占总量的98%以上;直径≤2.0 mm的比根长、根体积和根表面积占总量的50%以上;钾素对西瓜幼苗直径≤2.0 mm、2.5 mm<直径≤3.0 mm、3.5 mm<直径≤4.0 mm的根长、比根长、根表面积、根体积影响最明显。由于细根的吸收活力比较强,而西瓜细根所占比例最大,因此缺钾条件下,西瓜幼苗钾营养状况受到的影响较根系生长受到的影响更为严重。适宜的钾浓度有利于西瓜幼苗的生长,提高幼苗的生长质量,促进根系的生长发育,而不施钾和高钾处理会抑制幼苗的生长,但高钾对根系生长的抑制作用不明显。在本试验条件下,综合考虑经济因素,240 kg.hm 2钾肥施用量对西瓜幼苗生长和根系形态建成效果最明显。     

钾素营养对不同部位棉铃纤维品质性状的影响

在大田试验条件下,研究了钾素营养对上、下部位棉铃纤维品质性状的影响。试验选用2个品种,4个施钾量（K2O 0,60,180和300 kg/hm2）。结果表明:施钾提高了上、下部棉铃的纤维长度,增大了最终纤维麦克隆值,且随施钾量的增加,增幅呈加大趋势,但施钾对纤维长度达最大值的时间无影响;施钾提高了上、下部位棉铃纤维的最终零隔距比强度和3.2 mm隔距比强度,但在上、下部位棉铃间表现存在一定差异,下部棉铃纤维的最终零隔距比强度和3.2 mm隔距比强度均随施钾量的增加呈先增加后降低趋势,上部铃则随施钾量增加一直呈增大趋势;施钾还提高了上、下部棉铃纤维的最终成熟度,而且其增幅随施钾量的增加而增大,当施钾量为300 kg/hm2时,可显著增加上、下部位棉铃纤维的最终成熟度。     

Relationship between molecular characteristics of soil humic fractions and glycolytic pathway and krebs cycle in maize seedlings

A humic acid (HA) isolated from a volcanic soil was separated in three fractions of decreasing molecular size (I, II and III) by preparative high performance size exclusion chromatography (HPSEC). The molecular content of the bulk soil HA and its size fractions was characterized by pyrolysis-GC-MS (thermochemolysis with tetramethylammonium hydroxide) and NMR spectroscopy. All soil humic materials were used to evaluate their effects on the enzymatic activities involved in glycolytic and respiratory processes of Zea mays (L.) seedlings. The elementary analyses and NMR spectra of the humic fractions indicated that the content of polar carbons (mainly carbohydrates) increased with decreasing molecular size of separated fractions. The products evolved by on-line thermochemolysis showed that the smallest size fraction (Fraction III) with the least rigid molecular conformation among the humic samples had the lowest content of lignin moieties and the largest amount of other non-lignin aromatic compounds. The bulk HA and the three humic fractions affected the enzyme activities related to glycolysis and tricarboxylic acid cycle (TCA) in different ways depending on molecular size, molecular characteristics and concentrations. The overall effectiveness of the four fractions in promoting the metabolic pathways was in the order: III>HA>II>I. The largest effect of Fraction III, either alone or incorporated into the bulk HA, was attributed to a flexible conformational structure that promoted a more efficient diffusion of bioactive humic components to maize cells. A better knowledge of the relationship between molecular structure of soil humic matter and plant activity may be of practical interest in increasing carbon fixation in plants and redirect atmospheric CO₂ into bio-fuel resources.     

钾营养对棉花苗期生长和叶片生理特性的影响

在田间试验条件下,研究了施钾对棉花苗期生长和功能叶片生理特性的影响。试验设2个品种,4个施钾量。结果表明,施钾增加了棉花株高和单株叶片数,而对单株叶面积的影响不同,当施钾(K2O)量为180.kg/hm2时,叶面积达最大值,继续增施钾肥叶面积减小;施钾促进了叶绿素的合成,同时增加了叶绿素荧光动力学参数Fv/Fo、Fv/Fm和qP值,降低了qN值,增加了PSⅡ的实际量子效率(ФPSⅡ)和光合电子传递速率(ETR),从而提高了棉花功能叶的光合功能;施钾还增加了叶片中生长素(IAA)、玉米素核苷(ZR)、赤霉素(GA3)的含量,降低了脱落酸(ABA)的含量,提高了IAA/ABA、ZR/ABA、GA3     

钾钙镁营养对香蕉生长和叶片生理特性的影响

在田间试验条件下,研究了不同钾钙镁营养条件下香蕉生长和叶片生理特性的变化。结果表明,适量增施K、Ca及Mg肥有利于香蕉植株的生长发育,有利于为香蕉果实的生长发育提供良好的物质基础。且能有效促进叶片叶绿素的合成,提高叶片净光合速率,从而有效提高叶片光合作用能力。适量增施K、Mg肥能降低叶片抗氧化酶活性及膜脂过氧化强度,从而有效延缓叶片衰老。在广东高州市香蕉主产区,钾钙镁适宜用量为K2O 990、Mg 37.5、Ca 90.0 kg/hm2。     

Influence of potassium nutrition on norflurazon activity in wheat

Wheat (Triticum aestivum L. cv Stacy) was grown hydroponically and 7‐day old seedlings were exposed to K⁺ (6, 12, 24, or 48mM) and/or norflurazon[4‐chloro‐5‐(methylamino)‐2‐(3‐(trifluoromethyl)phenyl)‐3(2H)‐pyrdazinone] (0, 0.05, 0.10, 0.20, 0.41, or 0.82 μM) for 14 days. Carotenoid content was decreased by high K⁺ nutrition (12–48 mM), but norflurazon‐induced inhibition of carotenogenesis was not observed at high K⁺ nutrition. Phytoene desaturation product concentrations were influenced by K⁺ nutrition.     

植物镍营养

本文主要论述了镍对植物生长的必需性和土壤镍的植物有效性.现已证明,镍是高等植物的必需微量元素.它作为脲酶的金属辅基参与氮代谢,从而对高等植物生命周期的完成是必不可少的.土壤平均镍含量为5～50mg/kg,其形态包括水溶态、交换态、吸附态和矿物态.其中对植物有效的包括水溶态、交换态和部分吸附态镍.镍的植物有效性受土壤pH、质地和土壤有机质等影响.     

间作系统氮调控对小麦氮钾营养及条锈病发生的影响

通过探讨间作和施氮对小麦植株氮钾养分吸收、分配及条锈病发生的影响,明确氮钾养分吸收和分配与小麦条锈病发生的关系,以期为合理施肥实现控病增产提供理论依据。在云南安宁和峨山两地布置田间小区试验,研究3种施氮水平(0 kg×hm~(–2)、90 kg×hm~(–2)和180 kg×hm~(–2))和2种种植模式(小麦单作、小麦||蚕豆间作)对小麦植株氮钾含量与分配以及小麦条锈病发病率及病情指数的影响。结果表明,施氮增加了小麦产量,且间作增产效应显著;与单作相比,间作小麦平均显著增产31.9%(安宁)和18.0%(峨山);小麦||蚕豆间作产量优势明显,土地当量比为1.20～1.37(安宁)和1.16～1.27(峨山),但间作增产优势随施氮量增加而降低。施氮在提高产量的同时也加重了小麦条锈病危害,随施氮量增加,单、间作小麦条锈病的发病率和病情指数均呈增加趋势。间作有较好的控病效果,与单作相比,间作小麦发病率、病情指数分别显著降低9.6%～22.0%、23.7%～33.7%(安宁)和29.5%～36.5%、29.3%～39.6%(峨山)。施氮增加了小麦植株氮含量,且主要累积在叶片,叶片氮含量占氮吸收总量的41.3%～47.4%(安宁)和35.9%～44.1%(峨山);但间作显著降低小麦植株氮含量,并显著提高钾含量,因而显著降低了叶片氮/钾比。相关性分析表明,小麦条锈病发病率和病情指数与植株氮含量、叶片氮/钾比呈显著正相关,与钾含量呈极显著负相关。施氮增加了小麦植株氮含量,提高了叶片氮/钾比,进而加剧小麦条锈病发生;而间作则通过增加钾含量,降低小麦植株氮含量及叶片氮/钾比,平衡小麦植株内氮钾养分而增强小麦对条锈病的抗性。     

氯化钾对脐橙园土壤–树体氯积累及叶片营养和果实品质的影响

  【目的】  探讨施用氯化钾对脐橙叶片营养、果实产量及品质的影响,分析土壤和植株中氯元素含量与积累状况。  【方法】  以9年生纽荷尔脐橙为试材,于2018—2019年连续进行了两年田间试验。脐橙果园土壤一个为酸性、一个为碱性。氯化钾年施用量处理为250 g/株 (T1)、500 g/株 (T2)、1000 g/株 (T3),以硫酸钾556 g/株为对照 (CK)。在果实成熟期,测定了春梢和秋梢叶片中的N、P、K、Ca、Mg、Cl元素和相对叶绿素含量,测产并取样测定了果实品质及Cl–含量,在施肥后测定了0—20和20—40 cm土壤中的Cl–含量。  【结果】  1) 施用不同量氯化钾后果皮、果肉中氯元素含量没有显著变化,土壤和叶片中氯元素含量显著增加。T1处理在酸性土中氯元素含量较碱性土中多,与CK相比,T1处理酸性土中氯元素含量平均增加50.20%,而碱性土增加28.02%;T2处理氯元素含量在酸性土与碱性土中相差不大;T3处理氯元素含量在碱性土中大于酸性土中,与CK相比,酸性土增加79.70%,碱性土增加99.36%。2)T1处理下,在酸性土上脐橙春、秋梢叶片氯元素含量较CK分别增加了21.9%和8.0%,在碱性土上分别增加25.5%和12.7%;T2处理下,在酸性土上分别增加51.9%和45.0%,碱性土上分别增加33.3%和19.3%;T3处理下,在碱性土上分别增加109.7%和98.7%,而在酸性土上分别增加63.8%和58.0%。施用氯化钾后叶片中相对叶绿素、氮和钙元素含量没有显著变化,钾和部分磷元素含量随氯化钾施用量的增多呈增加趋势,镁元素含量略有下降。3) 施用氯化钾对果实产量、单果重、亮度、黄色度、可溶性固形物和可滴定酸含量均没有显著影响,部分果实红色度在施用氯化钾代替硫酸钾后显著提高,维生素C含量随氯化钾浓度的增高有增加趋势。  【结论】  短期施用氯化钾对果实中氯元素含量无显著影响,土壤和叶片中氯元素含量则显著增加,但均处在安全阈值以内。短期施用氯化钾对柑橘果实产量及品质无显著不良影响,叶片营养受影响较小,因此,酸、碱性土壤脐橙园短期内施用适量的氯化钾代替硫酸钾是可行的。     

干旱胁迫下钾素对甘薯碳水化合物及内源激素含量的影响

【目的】研究干旱胁迫下施钾量对不同生长时期甘薯碳水化合物及内源激素含量的影响,为甘薯的抗旱高产栽培提供理论依据。【方法】选用食用型甘薯品种‘泰中6号’为材料,以硫酸钾（K₂SO₄）为供试肥料,水分处理设土壤最大持水量的60%～70%和30%～40%,依次代表正常供水（W1）和干旱胁迫（W0）;钾肥设K0、K1、K2、K3四个水平,K₂O用量分别为0、120、240和360 kg/hm2。分析了不同生长时期甘薯干物质含量、淀粉和可溶性糖含量、内源激素含量及收获期块根产量。【结果】干旱胁迫下甘薯植株干物质含量、块根和淀粉产量显著降低,施钾有利于甘薯植株干物质含量的提高、块根的膨大和淀粉的生成和积累,甘薯植株和块根干物质含量、块根淀粉含量和积累量最大均为K2处理,较K0提高幅度最大分别达到31.7%、43.6%、10.6%和50.6%。相同钾用量条件下,干旱胁迫下块根单薯重显著高于正常灌水,单株结薯数显著低于正常灌水。正常灌水条件下施钾后甘薯叶片可溶性糖含量降低,而块根可溶性糖含量升高,干旱胁迫下施钾使甘薯叶片和块根可溶性糖含量增大,较K0提高幅度最高分别达到31.4%和36.0%。干旱胁迫下施钾后甘薯叶片和块根IAA、ABA、ZR和GA含量显著增大,较K0提高幅度最高分别达到12.7%、15.7%、12.0%、10.4%和21.4%、15.6%、65.7%、13.0%,促进了甘薯植株碳水化合物含量和干重的提高,块根淀粉积累速率增大。【结论】干旱胁迫下施钾促进了干物质向块根的分配,提高了甘薯块根单薯重,从而增加了单位面积甘薯块根产量。干旱胁迫下钾素提高甘薯块根和叶片内源激素（ABA、IAA、ZR、GA）含量,块根内源激素含量的增加促进了块根淀粉的合成和积累,叶片内源激素含量的增加促进了地上部茎叶生长、茎叶干物质积累和叶片可溶性糖含量的增加,增强了甘薯的抗旱性。