Common reed absorbs K+ more selectively than rice against high Na+/K+ ratio in nutrient solution     

Kyoko Higuchi  Kumiko Hara 《Soil Science and Plant Nutrition》2013,59(5):483-487

The introduction of an active Na⁺ excretion system from salt-tolerant plants in salt-sensitive crop plants might necessitate enhancement of the robustness of K⁺ homeostasis and lead to improved plant growth under salt stress. To address this issue, we compared the acquisition and retention of K⁺ under excess Na⁺ concentrations in the common reed, which possesses excellent Na⁺ excretion ability, and low-Na⁺ excreting rice. Under excess Na⁺ concentrations, common reed maintained constant K⁺ content in all plant parts, whereas K⁺ content in rice decreased with increasing Na⁺ concentration. Preferential uptake of K⁺ against high Na⁺/K⁺ ratio in nutrient solution was approximately 10 times higher in common reed than in rice. The impact of excess Na⁺ on net K⁺ absorption rate of common reed was small. On the other hand, the net K⁺ absorption rate of rice was decreased by excess Na⁺ concentration. However, after the Na⁺ concentration in the nutrient solution was decreased from 50 to 1 mM, K⁺ absorption in rice recovered immediately. Thus, selectivity of K⁺ transporters or channels for K⁺ over Na⁺ in roots could be involved in the differences in K⁺ accumulation in rice and common reed.  相似文献   

Effect of potassium on uptake and translocation of sodium and potassium in Chinese cabbage under NaCl stress     

Hai Yun Li 《Journal of plant nutrition》2019,42(3):250-260

To investigate the influence of potassium (K⁺) on the salinity tolerance of Chinese cabbage (Brassica pekinensis Rupr.) seedlings, the plants were cultured at three K⁺ levels (0, 5, or 10?mM), under normal (0?mM NaCl) and high-salt (100?mM NaCl) conditions. The results indicated that the dry weight of Chinese cabbage increased with the application of K⁺ under salt stress. Addition of K⁺ increased K⁺ concentrations and suppressed sodium (Na⁺) concentration, which eventually increased the K⁺/Na⁺ ratios in roots or shoots. Application of K⁺ enhanced the uptake of K⁺ and suppressed the uptake of Na⁺. Moreover, the ratios of shoot-K⁺/root-K⁺ increased considerably, but the ratios of shoot-Na⁺/root-Na⁺ decreased in response to K⁺ application. It was concluded that the application of K⁺ could enhance the salt stress tolerance in Chinese cabbage because more K⁺ than Na⁺ was absorbed and translocated from roots to shoots.  相似文献   

不同铵钾比对高铵下拟南芥地上部和根系生长的影响   总被引：1，自引：0，他引：1  

宋海燕  李光杰  施卫明 《土壤》2016,48(6):1077-1084

钾在缓解植物铵毒害的过程中起着重要的作用。本文研究了高铵(30 mmol/L)条件下,不同铵钾比(7.5︰1和150︰1)对拟南芥(Col-0)主根、侧根以及地上部生长的影响。结果表明:30 mmol/L NH4+条件下,高铵钾比(150)处理显著加重了拟南芥铵毒害现象,地上部和根系生长所受的抑制作用更为明显并导致更严重的氧化胁迫。相比低铵钾比水平,在高铵处理下,高铵钾比使得拟南芥主根伸长量降低57.4%,侧根数量减少33.3%,而地上部鲜重减轻69.9%。DAB(3,3￠-二氨基联苯胺,3,3￠-diaminobenzidine)叶片染色结果表明,不加铵处理下,外源不同钾水平(0.2和4.0 mmol/L)对拟南芥叶片的氧化胁迫作用没有显著差异;而高铵处理下,相比低铵钾比处理,高铵钾比显著增加了叶片中过氧化氢的含量,加重了其氧化胁迫。伊文思蓝(Evans blue,EB)染色结果表明,不加铵处理下,外源不同钾水平对拟南芥地上部和根部的膜透性没有显著差异,而高铵处理下,高铵钾比显著增强了拟南芥地上部和根部的膜透性,表明其对细胞的伤害程度加重。可见,高铵抑制拟南芥根系和地上部生长,高铵钾比则会加重这种抑制,其原因除了高浓度钾能减少植物对铵的吸收外,可能与高铵钾比条件加剧了植物的氧化胁迫有关。因此,适宜的铵钾比在植物应对铵毒害的过程中发挥重要作用。  相似文献   

Study of K+ uptake kinetics of flue-cured tobacco in K+-enriched and conventional tobacco genotypes     

Jun Zhong 《Journal of plant nutrition》2019,42(7):805-811

Screening of potassium efficient genotypes will be one of the best ways to solve the low potassium content of flue-cured tobacco. The study was conducted to determine whether the potassium efficient genotypes could be screening with high K⁺ uptake efficiency. The K⁺ uptake characteristics of a high K⁺ content line (GK8) and the conventional cultivated variety (K326) of flue-cured tobacco were compared at the seedling stage. K_m, C_min, and I_max values were higher in young seedlings (4?～?5 versus 6?～?7 leaf stage) and cultures with high initial K⁺ concentration (0.35 versus 0.25?mmol?L^?1). Culture solutions with a high K⁺ concentration (2.0 versus 0.6?mmol?L^?1) showed a high K_m, and C_min, but the I_max was lower as compared with the young seedlings and the solution with high initial K⁺ concentration. In conclusion, the GK8?line had a stronger ability for limited K⁺ uptake than K.  相似文献   

Negative correlation between the ratio of K+ to Na+ and proline accumulation in tobacco suspension cells     

Eiji Okuma  Kenji Soeda  Miho Fukuda  Mikiro Tada  Yoshiyuki Murata 《Soil Science and Plant Nutrition》2013,59(5):753-757

Abstract

The concentrations of K⁺, Na⁺, and proline and the ratio of K⁺ to Na⁺ (K⁺ / Na⁺) were analyzed in NaCl-unadapted and NaCl-adapted tobacco (Nicotiana tabacum) cells in suspension culture. At 3 to 5 d after inoculation, the NaCl-unadapted cells cultured in 100 mmol L^?1 NaCl saline culture medium (Na100 medium) accumulated 28.7 mmol L^?1 proline with a low ratio of K⁺ to Na⁺ (= 2.8) and the NaCl-adapted cells cultured in the Na100 medium contained 6.28 mmol L^?1 proline with a high K⁺ / Na⁺ ratio (≧ 7.5). The contents of amino acids for the NaCl-adapted cells in the Na100 medium were similar to those for the NaCl-unadapted cells in a modified LS medium (standard medium). At 14 d after inoculation, the NaCl-unadapted cells in the Na100 medium contained 4.77 mmol L^?1 proline and restored the K⁺ / Na⁺ ratio from 2.8 to 6.2. These results indicate the presence of a negative correlation between the K⁺ / Na⁺ ratio and proline accumulation and suggest that a balance between the K⁺ / Na⁺ ratio and proline accumulation may be the factor involved in determining the salt tolerance of plant cells.  相似文献   

Characterizing nicotianamine aminotransferase: Improving its assay system and details of the regulation of its activity by Fe nutrition status     

Kenji Kanazawa  Kyoko Higuchi  Hiromi Nakanishi  Naoko Kishi-Nishizawa  Satoshi Mori 《Soil Science and Plant Nutrition》2013,59(4):717-721

Under iron deficient conditions, graminaceous plants secrete mugineic acid family phytosiderophores (MAs) from their roots to dissolve sparingly soluble iron compounds in the rhizosphere, and take up iron in the form of an Fe³⁺-MAs complex (Takagi 1976). A good correlation has been reported between the tolerance of Fe-deficiency and the amount of secreted MAs (Takagi 1993). Therefore, by using the genes involved in MAs biosynthesis, molecular breeding might produce transgenic plants tolerant to Fe-deficiency with a high level of MAs secretion. The biosynthetic pathway of MAs from L-methionine has been clarified (Fig. 1) and the enzymes participating in this process are now being investigated to isolate the genes responsible. Nicotianamine aminotransferase (NAAT) catalyzes the amino group transfer between nicotianamine (NA) and 2-oxoglutaric acid (Fig. 1). In order to purify NAAT, enzyme assay methods for NAAT have been developed and modified (Shojima et al. 1990; Ohata et al. 1993; Kanazawa et al. 1994). Some characteristics of NAAT have been reported using these enzyme assay methods (Kanazawa et al. 1994, 1995). Here, we further investigate some characteristics of this enzyme to improve the enzyme assay method, namely 1) the effect of K⁺ and Mg²⁺ on NAAT activity in vitro, and 2) the direct influence of MAs, Fe³⁺, and Fe²⁺ on NAAT activity. In addition, based on these results, the induction of enzyme activity by Fe-deficiency and suppression of the activity by Fe-resupply was investigated, by applying the new enzyme assay method.  相似文献   

SELECTIVITY AND PARTITIONING OF POTASSIUM AND SODIUM IN SESAME     

Asha Yahya 《Journal of plant nutrition》2013,36(5):670-683

Net uptake and partitioning of sodium (Na⁺) and potassium (K⁺) in plants of two sesame cultivars (Sesamum indicum cv. ‘PB-1’ and cv. ‘UCR’) exposed to 20 mM sodium chloride (NaCl) were studied over a period of 28 days. Both cultivars showed a marked discrimination between K⁺ and Na⁺ during uptake. The reduction of K⁺ in the plants caused by the NaCl treatment was of similar magnitude in the two cvs. The cv. ‘UCR’ showed lower Na⁺ concentrations in the shoot tissues than ‘PB-1’ and K⁺/Na⁺ selectivity ratios were higher in cv. ‘UCR’ than in cv. ‘PB-1’. At the last sampling on day 28 there was a marked decrease of shoot growth in cv. ‘PB-1’ in comparison to the cv. ‘UCR’. Leaves of cv. ‘PB-1’ showed clear toxic symptoms, while those of cv. ‘UCR’ did not. It is concluded that Na⁺ exclusion from the shoot contributes to salt tolerance of sesame, cv. ‘UCR’.  相似文献   

NO^-₃胁迫下K⁺、Ca²⁺对黄瓜幼苗膜质过氧化及活性氧清除酶系统的影响     

杨凤娟  王秀峰  魏珉  闫童 《农业工程学报》2005,21(14):155-158

通过水培试验探讨了NO^-₃胁迫下K⁺、Ca²⁺对黄瓜幼苗膜质过氧化及活性氧清除酶系统的影响。结果表明，在相同NO^-₃浓度胁迫7d后， Ca²⁺浓度越大，膜脂过氧化产物丙二醛(MDA)含量越高，而K⁺浓度越大，电解质相对渗透率越高，由此说明K⁺、Ca²⁺对细胞膜造成伤害的机理不同。黄瓜幼苗活性氧清除酶系统对K⁺、Ca²⁺的响应亦不同，在一定程度上，K⁺和Ca²⁺ 可提高SOD、POD和CAT活性，保护植物免受自由基伤害，继而可增强植物对逆境的适应能力。  相似文献   

Response of plant yield and leaf pigments to saline conditions: Effectiveness of different rootstocks in melon plants (Cucumis melo L.)     

Luis Romero  Amal Belakbir  Lamia Ragala  Juan M. Ruiz 《Soil Science and Plant Nutrition》2013,59(4):855-862

Two varieties of Cucumis melo (Resisto and Arava) were grafted onto three hybrids of Cucurbita maxima and Cucurbita moschata cultivars (Shintoza, RS-841 and Kamel). Ungrafted Cucumis melo var. Resisto and var. Arava plants were used as controls. Plants were grown under controlled greenhouse conditions and were constantly fertilized with macro- and micronutrients, supplied with irrigation water rich in Na⁺ and Cl^- Contents of chlorophylls a and b, carotene pigments, Cl^- and total and soluble Na⁺ and K⁺ ions were measured in all the scion parts of the plants. The results showed that grafted plants exhibited differences in the leaf content of Na+ and especially Cl^- in comparison with ungrafted plants. In addition, yield as well as leaf pigments appeared to be good indicators of Cl^- levels in scion parts. It is assumed that grafted plants developed various mechanisms to avoid physiological damage caused by the excessive accumulation of these ions in leaf, including the exclusion of Cl^- ion and/or decrease in Cl^- absorption by the roots and the replacement or substitution of total K⁺ by total Na⁺ in the foliar parts.  相似文献   

Use of IR thermography in screening wheat (Triticum aestivum L.) cultivars for salt tolerance     

Alireza Esmaeili  Hojat Ahmadi  Alireza Abbasi 《Archives of Agronomy and Soil Science》2017,63(2):161-170

Thermography is proposed to be an alternative non-destructive and rapid technique for the study and diagnosing of salt tolerance in plants. In a pot experiment, 30 cultivars of wheat (Triticum aestivum L.) were evaluated in terms of their leaf temperature and shoot growth and their ion distribution responses to NaCl salinity at two concentration levels: the control with electrical conductivity (EC) of 1 dS m^?1 and salinity treatment with EC of 16 dS m^?1 (150 mM). A completely randomized block design with factorial treatments was employed with three replications. The results indicated that thermography may accurately reflect the physiological status of salt-stressed wheat plants. The salt stress-based increase in leaf temperature of wheat cultivars grown at 150 mM NaCl reached 1.34°C compared to the control. According to the results obtained, it appears that thermography has the capability of discerning differences of salinity tolerance between the cultivars. Three salt-tolerant wheat cultivars, namely Roshan, Kharchia and Sholeh, had higher mean shoot dry matter (0.039 g plant^?1) and higher mean ratio of leaf K⁺/Na⁺ (14.06) and showed lower increase in the mean leaf temperature (0.37°C) by thermography compared to the control. This was while nine salt-sensitive cultivars, namely Kavir, Ghods, Atrak, Parsi, Bahar, Pishtaz, Falat, Gaspard and Tajan, had lower mean plant dry matter production (0.027 g plant^?1), lower mean ratio of K⁺/Na⁺ (9.49) and higher mean increases in leaf temperature (1.24°C).  相似文献   

Methionine sulfoximine suppressed the stimulation of dark carbon fixation by ammonium nutrition in wheat roots     

Nobuhisa Koga  Motoki Ikeda 《Soil Science and Plant Nutrition》2013,59(2):393-400

To evaluate the role of NH₄ ⁺ assimilates in dark carbon fixation in roots in providing carbon skeletons expended for NH₄ ⁺ assimilation, the rate of dark carbon fixation in roots was measured using NaH¹⁴CO₃. The ¹⁴C-metabolites were analyzed in wheat (Triticum aestivum L.) plants grown in NH₄ ⁺ media for various periods of time with or without methionine sulfoximine (MSX) treatment. The dark carbon fixation rate in the roots of wheat plants that had been grown with NH₄ ⁺ for 1 d was approximately 6-fold higher than the rate in control roots. The stimulation of dark carbon fixation in NH₄ ⁺-grown plants, however, was not observed in MSX-treated roots. In the roots of NH₄ ⁺-grown plants, the concentration and ¹⁴C-Iabeling of acidic metabolites such as citrate and malate considerably decreased whereas those of basic metabolites, especially asparagine, increased noticeably. With MSX treatment, the incorporation of ¹⁴C into basic metabolites was negligible. In response to NH₄ ⁺, phosphoenolpyruvate carboxylase (PEPC) activity increased, and PEPC proteins accumulated in wheat roots. Neither activity nor amounts of PEPC in roots increased in the presence of MSX. These findings suggest that primary assimilation of NH₄ ⁺ in roots is essential for the stimulation of dark carbon fixation, which coincides with the increased activity of root PEPC, to sufficiently replenish carbon skeletons necessary for NH₄ ⁺ assimilation.  相似文献   

局部根系盐胁迫对冬小麦生长和光合特征的影响   总被引：3，自引：1，他引：2  

杨婷  谢志霞  喻琼  刘小京 《中国生态农业学报》2014,22(9):1074-1078

通过分根装置设置无盐胁迫(0|0)、局部根系150 mmol-L-1NaCl胁迫(0|150)、全部根系75 mmol-L-1NaCl胁迫(75|75)、全部根系150 mmol-L-1NaCl胁迫(150|150)4种处理,研究根系局部盐胁迫对冬小麦生长及光合特征的影响。结果表明:盐胁迫显著抑制了小麦幼苗的生长,并且随着盐胁迫浓度的增加,小麦受抑制程度加重;根系盐胁迫方式对小麦幼苗生长影响显著,局部根系胁迫处理(0|150)小麦幼苗地上部干重比等浓度150 mmol-L-1NaCl全部盐胁迫处理(150|150)增加23.5%,比等浓度75 mmol-L-1NaCl全部盐胁迫处理(75|75)增加17.2%。在局部根系盐胁迫下,非盐胁迫一侧根系(0|150-0)补偿生长,其根长、侧根数、侧根长比盐胁迫一侧根系(0|150-150)分别增加195.2%、206.2%和237.8%,盐胁迫一侧根系吸收的Na+部分向非盐胁迫一侧根系运输,盐胁迫一侧根系(0|150-150)的Na+含量比全部胁迫处理(150|150)减少12.1%。与全部根系盐胁迫相比,局部根系盐胁迫减少了Na+在叶片中的积累,降低了钠/钾值。局部根系盐胁迫叶片净光合速率、气孔导度、胞间CO2浓度和叶绿素荧光参数(Fv/Fm)均高于同浓度完全盐胁迫处理的小麦幼苗,进而增加地上部和根系的生物量。因此,局部根系胁迫显著缓解了全部盐胁迫对小麦地上部和根系生长的抑制作用。  相似文献   

EFFECTS OF WATER SALINITY ON GROWTH INDICES AND PHYSIOLOGICAL PARAMETERS IN SOME PISTACHIO ROOTSTOCKS     

H. R. Karimi  A. Ebadi  Z. Zamani  R. Fatahi 《Journal of plant nutrition》2013,36(7):935-944

Pistachio is one of the most important horticultural crops in Iran. The majority of the pistachio producing regions is located in arid and semi-arid areas with saline conditions. Therefore, selection of suitable rootstocks is important for increasing yield efficiency of this important nut crop. In this study, the effect of four water salinity levels (0.75, 5, 10 and 15 ds m^?1) on growth indices and physiological parameters of four Pistacia vera L. rootstocks (Badami-e-Zarand A, Badami-e-Zarand B, Qazvini, and Sarakhs) were investigated under greenhouse conditions. After treatment for three months, leaf dry weight was reduced by about 30-50% at an irrigation water electrical conductivity (EC_w) of 10 ds m^?1. Badami-e-Zarand B was the most vigorous rootstock at the highest EC. Decreases in root and stem dry weight (average of all rootstocks combined) occurred at water salinity of 10 ds m^?1. Chemical analysis of shoot and root indicated that the salinity affected the concentration and distribution of sodium (Na⁺), potassium (K⁺), and calcium (Ca²⁺) in pistachio rootstocks. The concentrations of Na⁺ and K⁺ increased with a rise in water salinity levels. Comparison between Na⁺ concentration of shoot and root showed that all examined rootstocks limited the Na⁺ transportation to shoot tissue up-to 15 ds m^-1, and retained it in the roots. However, this ability was less in the Sarakhs rootstock. Based on measured parameters, Badami-e-Zarand B and Sarakhs could be considered as tolerant and sensitive pistachio rootstocks to water salinity, respectively.  相似文献   

EFFECTS OF SALINITY STRESS ON PHYSIOLOGICAL PERFORMANCE OF VARIOUS WHEAT AND BARLEY CULTIVARS     

Mohammad Hossein Izadi  Javad Rabbani  Yahya Emam  Mohammad Pessarakli  Ahmad Tahmasebi 《Journal of plant nutrition》2014,37(4):520-531

An experiment with factorial arrangement of treatments on a randomized complete block (RCB) design basis with three replications was conducted in a greenhouse during Spring 2010 to investigate changes in sodium ion (Na⁺), potassium ion (K⁺), Na⁺/K⁺ and to determine proline, protein content, and superoxide dismutase (SOD) of four wheat and four barley cultivars. Three salt levels {1, control (no salt), 7, and 13 dS m^?1 [2.5 and 5 g salt [sodium chloride (NaCl) and sodium sulfate (Na₂SO₄) in 1:1 ratio] per kg of soil, respectively]} were used in this investigation. Salt stress treatments were applied 4 weeks after planting (at 2 leaf stage). Leaf samples were taken four weeks after imposition of salt treatment. The results showed that salinity caused an increased in proline and protein content, and SOD in all wheat and barley cultivars. The highest proline and protein content of barley and wheat cultivars at all salinity levels were observed in ‘Nimrooz’ and ‘Bam’ cultivars, respectively. At all salinity levels, wheat and barley cultivars ‘Kavir’ and ‘Nimrooz’, respectively, had the lowest Na⁺ content. Barley cultivar ‘Kavir’ and wheat cultivar ‘Bam’ had higher K⁺ and K⁺:Na⁺ ratios. This might be related to salt tolerance in these two cultivars. Wheat and barley cultivars showed differences with regard to proline, protein, and SOD content, Na⁺, K⁺, and K⁺:Na⁺ ratio, indicating existence of genetic diversity among the cultivars. These findings indicated that higher K⁺, K⁺:Na⁺ ratio, proline, protein, and SOD content could be the key factors, which offer advantage to barley over wheat for superior performance under saline conditions.  相似文献   

Relationship between Gu(II) sorption and active H+ sorption sites of soils     

I-Song Choi  Masanori Okazaki  Noriko U. Yamaguchi 《Soil Science and Plant Nutrition》2013,59(3):527-535

Sorption characteristics of Cu(PI) were investigated using six soils coPBected in Korea (JUF9 SUM, and HHM) and in Japan (HNG, TWD, and ISM). The Cu(IH) sorption amount increased with increasing initial Cu(II) concentration. The maximnm sorption amount of @u(PI) increased in the order of KHM< ISK< JUM < JUF < TWD < KNG, and was related to the pH and BZSE of soils. The H⁺ release curves due to Cu(II) sorption apparently were characterized by a two or three step pattern. The amount of H⁺ released due do Cu(II) sorption increased with the increase in the Cu(II) sorption amount. The amount of protons released per Cu(II) sorbed onto soils with a larger Gu(II) sorption amount tended to be smaller compared with soils with a smaller Cu(HHQ sorption amount. The W⁺ sorption amount of the original soils and those with Cu(II) sorption at the PZSE, which was referred to as σ_P (Sakurai et al. 1988: Soil Sci. Plant Nutr., 34, 171–182; 1996: Jpn. J. Soil Sci. Plant Nutr., 67, 32–39), was determined by the STPT method proposed by Sakurai et al. (4988: Soil Sci. Plant Nutp., 34, 171–182). The active H⁺ sorption sites of soils were used for Cu(II) sorption and their amount decreased after Cu(II) sorption because they were covered with Cu(II). Soils with a larger amount of active H⁺ sorption sites exhibited a higher aEamity to Cu(II) khan those with a smaller amount of active H⁺ sorption sites. The Cu(II) sorption created a positive charge in soils, causing the decrease in the amount of active H⁺ sorption sites.  相似文献   

Influence of extreme K:Na ratios and high substrate salinity on plant metabolism of crops differing in salt tolerance     

G. Rathert  H.‐W. Doering 《Journal of plant nutrition》2013,36(3):261-277

K⁺/Na⁺ and Cl^‐ effects on activity of amylases as well as on their isoenzyme pattern in leaves of bushbeans and sugarbeets at the beginning of salinity stress were investigated, in plants grown in water culture under controlled environmental conditions. Alpha‐ and beta‐amylase activity in beans increased, particularly due to K⁺ and Cl^‐ supplied. In sugarbeets amylase activity remained unchanged as a result of K/Na treatment in combination with Cl and decreased using SO₄ ^2‐ as counterion. A direct correlation of amylase activity to the starch content of both species was not detctable. Particularly α‐but also ß‐amylase was most strongly inhibited by KCl “in vitro”. Independent on their origin, amylases from bushbeans and sugarbeets did not show any differences in ionic inhibition “in vitro”. The isoenzyme pattern of the species was different, but no clear ionic effect was detectable. Amylolytic activity is evidently not a causative factor for restricted starch mobilization in leaves under an early salinity stress. It is suggested that amylases are indirectly involved in starch formation via degradation due to a lack of a carbohydrate sink under salinity stress. Differences in salt tolerance of the investigated crops are obviously not related to different “in vitro” properties of amylases.  相似文献   

Evaluation of Extractants and Quantity–Intensity Relationship for Estimation of Available Potassium in Some Calcareous Soils of Western Iran     

《Communications in Soil Science and Plant Analysis》2012,43(17-18):2663-2677

Accurate estimation of the available potassium (K⁺) supplied by calcareous soils in arid and semi‐arid regions is becoming more important. Exchangeable K⁺, determined by ammonium acetate (NH₄OAc), might not be the best predictor of the soil K⁺ available to crops in soils containing micaceous minerals. The effectiveness of different extraction methods for the prediction of K‐supplying capacities and quantity–intensity relationships was studied in 10 calcareous soils in western Iran. Total K⁺ uptake by wheat grown in the greenhouse was used to measure plant‐available soil K⁺. The following methods extracted increasingly higher average amounts of soil K⁺: 0.025 M H₂SO₄ (45 mg K⁺ kg^?1), 1 M NaCl (92 mg K⁺ kg^?1), 0.01 M CaCl₂ (104 mg K⁺ kg^?1), 0.1 M BaCl₂ (126 mg K⁺ kg^?1), and 1 M NH₄OAc (312 mg K⁺ kg^?1). Potassium extracted by 0.01 M CaCl₂, 1 M NaCl, 0.1 M BaCl₂, and 0.025 M H₂SO₄ showed higher correlation with K⁺ uptake by the crop (P < 0.01) than did NH₄OAc (P < 0.05), which is used to extract K⁺ in the soils of the studied area. There were significant correlations among exchangeable K⁺ adsorbed on the planar surfaces of soils (labile K⁺) and K⁺ plant uptake and K⁺ extracted by all extractants. It would appear that both 0.01 M CaCl₂ and 1 M NaCl extractants and labile K⁺ may provide the most useful prediction of K⁺ uptake by plants in these calcareous soils containing micaceous minerals.  相似文献   

Exploitation of potassium by various crop species from primary minerals in soils rich in micas     

K. Mengel  Rahmatullah 《Biology and Fertility of Soils》1994,17(1):75-79

We investigated the question of whether exchangeable K⁺ is a reliable factor for K⁺ availability to plants on representative arable soils (Aridisols) rich in K⁺-bearing minerals. Five soils with different textures were collected from different locations in Pakistan and used for pot experiments. The soils were separated into sand, silt, and clay fractions and quartz sand was added to each fraction to bring it to 1 kg per kg whole soil, i.e., for each fraction the quartz sand replaced the weight of the two excluded fractions. On these soil fraction-quartz mixtures wheat, elephant grass, maize, and barley were cultivated in a rotational sequence. Growth on the sand mixture was very poor and except for the elephant grass all species showed severe K⁺-deficiency symptoms. Growth on the mixture with silt and clay fractions was much better than on the sand fraction; there was no major difference in growth and K⁺ supply to plants whether grown on silt or clay, although the clay fraction was rich and the silt fraction poor in exchangeable K⁺. On both these fractions the plant-available K⁺ supply was suboptimal and the plants showed deficiency symptoms except for the elephant grass. This plant species had a relatively low growth rate but it grew similarly on sand, silt, and clay and did not show any K⁺ deficiency symptoms, with the K⁺ concentration in the plant tops indicating a sufficient K⁺ supply regardless of which soil fraction the plants were grown in. The reason for this finding is not yet understood and needs further investigation. It is concluded that on soils rich in mica, exchangeable K⁺ alone is a poor indicator of K⁺ availability to plants and that mica concentrations in the silt and clay fraction are of greater importance in supplying crops with K⁺ than exchangeable K⁺.  相似文献   

A Correlation of Rapid Cardy Meter Sap Test and ICP Spectrometry of Dry Tissue for Measuring Potassium (K+) Concentrations in Pak Choi (Brassica Rapa Chinensis Group)     

Chandrappa Gangaiah  Amjad A. Ahmad  Hue V. Nguyen 《Communications in Soil Science and Plant Analysis》2016,47(17):2046-2052

Nutritional status of vegetable crops is often monitored by analysis of dried plant tissues, which is costly and often time consuming. Two greenhouse trials were conducted, at the University of Hawaii at Manoa, Magoon facilities, to evaluate the portable cardy ion meter (CIM) in determining potassium (K⁺) status in fresh petiole sap of pak choi as compared with standard laboratory methods. In the first greenhouse trial, three algae species (Gracilaria salicornia, Kappaphycus alvarezii, and Eucheuma denticulatum) were used to apply five rates of K⁺ (0, 84, 168,252, and 336 kg.ha^?1). The pak choi was directly seeded into 4 L pots and was grown in peat moss. In the second greenhouse trial, K+ was provided through Eucheuma denticulatum and potassium nitrate (KNO₃) at five rates (0,112, 168, 224, 280, and 336 kg.ha^?1) in peat moss and soil media. At harvest, K⁺ concentrations in fresh petiole sap were analyzed immediately with CIM and the dried samples were analyzed by inductively coupled plasma spectroscopy (ICP) measurement. The results showed increase in leaf K+ content at higher rates and the maximum concentration of leaf K⁺ at 4500–5300 mg/L for sap and 8–9% for tissue was obtained when K⁺ was provided between 224 and 284 kg.ha^?1. There was a close correlation between the CIM readings and the ICP method (r = 0.8048 and 0.8314) from the first and second GH results, respectively. The results suggest that the CIM could be used for the rapid monitoring of the relative K⁺ status of plants. The data further suggested 4500–5000 mg K/L for fresh petiole sap and 7.5% K⁺ in tissue as critical levels for K⁺ concentration in pak choi.  相似文献   

Effects of Fusicoccin and Vanadate on Proton Extrusion and Potassium Uptake by Rice     

Carlos Alberto Bucker  Sonia Regina de Souza  Manlio Silvestre Fernandes 《Journal of plant nutrition》2013,36(3):485-496

The effects of fusicoccin or vanadate on proton (H⁺) extrusion and potassium (K) uptake of four varieties of rice (oryza satiya L.) were studied. Two of them were improved varieties (IAC-47 and Agulha), with 70% genetic similarity. The two others were landraces (Bico Ganga and Piaui). Vanadate totally blocked H⁺-pumping activity while fusicoccin increased it. Potassium uptake was suppressed under vanadate but increased sharply under the fusicoccin treatment. The Piaui was the most affected by fusicoccin, while Agulha was the least affected. Under fusicoccin, Bico Ganga had a 48% increase in K uptake at the end of the experimental period in relation to the controls, while IAC-47 showed only a 17% increase. Taken together, for all varieties and treatments, there was a negative correlation between the final pH and the total K taken up by plants. This study suggests that some rice varieties need additional stimulation from external sources to express their full H⁺-pumping and K-uptake capabilities.  相似文献