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1.
【目的】盐胁迫是限制新疆番茄生长的重要障碍因子之一,而外源喷施谷胱甘肽 (GSH) 是解决这一问题的有效措施。探讨外源 GSH 缓解番茄盐胁迫的效应和作用机制,可为该措施的有效应用提供理论依据。 【方法】采用营养液栽培法,选用番茄品种‘中蔬四号’为试材。在营养液中加入 NaCl 100 mg/L,使其产生盐胁迫,以不加 NaCl 作为对照 (CK),试验处理包括不喷施 GSH (NaCl)、喷施 GSH (+ GSH)、喷施 GSH 合成酶抑制剂 (+ BSO) 以及喷施 GSH 和 BSO (+ BSO + GSH)。测定番茄幼苗叶片和根系中与耐盐性相关的 K+、Ca2+、Mg2+、Na+ 和 Cl– 的离子微域分布状态和平衡。 【结果】NaCl 胁迫下番茄叶片和根系所有组织细胞中 Na+ 和 Cl– 相对含量显著提高,K+ 相对含量和 K+/Na+、Ca2+/Na+、K+/Cl– 比值降低,说明 NaCl 胁迫使细胞中 Na+ 和 Cl– 有害离子积累及胞内离子稳态严重破坏;外源 BSO 施用进一步加剧了 NaCl 胁迫下番茄叶片和根系细胞的 K+/Na+ 失衡。而外源 GSH 施用抑制了 NaCl 胁迫下番茄叶片和根系对 Na+ 的吸收,降低了 Cl– 的相对含量,提高了 K+/Na+、Ca2+/Na+、K+/Cl– 比值。外源 GSH 亦使 NaCl+BSO 胁迫下番茄叶片各组织及根系中皮层、内皮层和中柱的 Na+ 未检出,根系和叶片各组织中 Cl– 相对含量显著降低,K+ 和 Ca2+ 相对含量及 K+/Na+、Ca2+/Na+、K+/Cl–、Ca2+/Cl– 比值显著提高。 【结论】外源 GSH 通过抑制盐胁迫下番茄叶片和根系对 Na+ 的吸收,降低 Cl– 吸收,改善细胞中离子的微域分布和维持离子平衡, 从而缓解了盐胁迫对番茄的毒害作用,提高了番茄的耐盐性。  相似文献   

2.
钙对NaCl胁迫下马铃薯脱毒苗离子吸收、分布的影响   总被引:3,自引:1,他引:2  
【目的】马铃薯是对盐分较敏感的农作物,土壤盐渍化会严重影响马铃薯的生长发育及其产量和品质。有关钙对Na Cl胁迫下马铃薯离子吸收、分布的研究较少。本文通过研究不同浓度Ca Cl2对Na Cl胁迫下马铃薯脱毒苗离子吸收、分布和运输的影响,探讨钙对Na Cl胁迫下马铃薯的调控机制,为盐渍土上马铃薯的生产提供理论依据与技术支持。【方法】以‘克新一号’马铃薯品种为试验材料,采用组织培养方法,将0、5、10、15和20 mmol/L Ca Cl2与0、25、50和75 mmol/L Na Cl分别添加到MS+2mg/L B9+3%蔗糖+0.9%琼脂培养基中,制成不同处理组合的培养基。将继代培养的脱毒苗按单节茎段剪切接种到培养基中进行培养。接种30天时调查脱毒苗生物量和Na+、Cl-、K+、Ca2+、Mg2+、P积累量,并分析Na+/K+、Na+/Ca2+、Na+/Mg2+比值及根系与茎叶的SK、Na、SMg、Na和SCa、Na值,探讨离子吸收、运输及分布情况。【结果】Na Cl胁迫抑制马铃薯脱毒苗的生长,随Na Cl胁迫浓度的增加,马铃薯脱毒苗鲜重、干重显著下降,各器官Na+和Cl-含量极显著增加,K+含量显著下降,Ca2+和Mg2+含量减少,茎、叶中P含量降低而根中P含量增加。Na+/K+、Na+/Ca2+、Na+/Mg2+比值随Na Cl胁迫浓度的增加而升高。随Na Cl胁迫浓度的增加,马铃薯脱毒苗根系与茎叶的SK、Na和SMg、Na值逐渐降低,SCa、Na值呈先升高后降低趋势。0、25和50 mmol/L Na Cl胁迫浓度下,以10 mmol/L Ca Cl2处理的马铃薯脱毒苗根、茎叶鲜重和干重最高,75 mmol/L Na Cl胁迫下以15 mmol/L Ca Cl2处理的马铃薯脱毒苗生物量最高。各Na Cl胁迫浓度下,添加Ca Cl2后,马铃薯脱毒苗各器官Na+含量明显降低,Cl-含量显著增加,K+、Ca2+、Mg2+含量升高,P含量先降低后升高。0、25、50和75 mmol/L Na Cl胁迫浓度下,添加适量Ca Cl2可明显降低马铃薯脱毒苗各器官Na+/K+、Na+/Ca2+、Na+/Mg2+比值,提高SK、Na、SMg、Na和SCa、Na值,增强K+、Ca2+、Mg2+向地上部的选择运输能力,抑制Na+向地上部的选择运输能力,维持细胞内离子平衡,缓解盐胁迫造成的营养亏缺。【结论】Na Cl胁迫下添加外源钙,能够有效改善马铃薯脱毒苗体内的离子平衡,促进营养吸收,Na+向叶片选择运输能力降低,K+、Ca2+、Mg2+向地上部的选择运输能力增强,离子在各器官水平上的区域化分布发生改变是钙缓解盐胁迫的重要生理机制之一。  相似文献   

3.
NaCl胁迫对葡萄幼苗根际pH值及营养成分的影响   总被引:2,自引:0,他引:2  
采用多隔层根际培养的方法,研究了NaCl胁迫下赤霞珠葡萄幼苗根际土和非根际土的pH值以及主要营养成分的变化。结果表明,NaCl处理对赤霞珠葡萄幼苗的生长造成了不同程度的抑制。不同NaCl处理下,葡萄幼苗根际土壤pH均低于非根际土,各层土壤的pH随盐胁迫程度加深而增高;水溶性K+在根际含量较低,水溶性Na+ 和Ca2+在根际富集。非盐渍条件下,葡萄幼苗根际碱解氮增高,而在盐胁迫下下降。在4 g/kg NaCl胁迫下,葡萄根际有效磷降低,其它处理下升高;而水溶性Mg2+ 则相反。试验结果还表明,Na+的存在阻碍了根系对多种矿质营养的吸收和利用,影响了葡萄的正常生理活动,不同程度地限制了葡萄根系的生活力和吸收能力。在Na+的作用下,K+、Ca2+、Mg2+的迁移和吸收受到不同程度的影响,与对照相比,各层土壤中的几种离子的含量均有所变化。  相似文献   

4.
为了探讨外源甘露醇和山梨醇对盐胁迫下甜瓜幼苗生长和离子平衡的影响,以甜瓜‘桂蜜12号’为试验材料,以Hoagland 营养液为培养液进行沙培(CK0),采用100 mmol/L NaCl模拟盐胁迫(CK1),然后添加不同浓度的甘露醇和山梨醇,观察不同处理的甜瓜幼苗生长情况和离子平衡变化。结果表明,在100 mmol/L NaCl盐胁迫(CK1)下,与对照(CK0)相比,甜瓜幼苗根系鲜质量、干质量、根总长度、根表面积以及根体积显著下降,K+/Na+、Ca2+/Na+、Mg2+/Na+显著降低。添加0.4 mmol/L的甘露醇,可显著增加甜瓜幼苗茎叶部Ca2+、Mg2+含量,而不增加Na+含量,不降低K+含量;显著提高Mg2+/Na+,而Ca2+/Na+及K+/Na+则与CK1持平。添加0.4 mmol/L的山梨醇显著提高地上部鲜重、幼苗根长、根表面积和根体积,显著降低盐胁迫甜瓜幼苗的Na+含量,提高Ca2+、Mg2+含量,显著提高Mg2+/Na+、K+/Na+、Ca2+/Na+。上述结果表明,适宜浓度的山梨醇和甘露醇可以缓解盐胁迫对甜瓜幼苗的伤害。在试验条件下,缓解盐胁迫对甜瓜幼苗根系及离子平衡影响的最适处理是添加0.4 mmol/L的山梨醇。  相似文献   

5.
为揭示不同白榆(Ulmus pumila L.)品系对滨海盐碱地土壤盐分的改良作用及盐分离子在土壤-白榆系统中的分布与吸收特征,筛选适宜在滨海盐碱地造林的耐盐白榆品系,以中度盐渍化生境下4年生的6种白榆品系(1,5,28,30,46,105号)为试验材料,采用野外取样与室内测试相结合的方法,研究了Na+、K+、Ca2+、Mg2+等盐离子在土壤及白榆品系各器官(根、茎、叶)中的分布特征。结果表明:(1)白榆可降低滨海盐碱地土壤中盐离子及全盐含量,不同白榆品系较对照的土壤全盐含量降低了55.0%~63.1%,30号白榆降幅最大。(2)不同白榆品系将Na+、K+、Ca2+、Mg2+优先积累到叶中,且叶中维持较高的K+/Na+、Ca2+/Na+、Mg2+/Na+比值,不同白榆品系通过建立新的离子平衡以适应盐胁迫环境。(3)不同白榆品系的离子吸收选择性系数均为SK,NaSCa,NaSMg,Na,其对K+的吸收选择性大于对Ca2+、Mg2+吸收选择性;种内差异导致不同白榆品系对Na+、K+、Ca2+、Mg2+吸收选择能力不同,28号白榆根系对K+的吸收性最强,5号白榆根系对Ca2+、Mg2+的吸收性最强。  相似文献   

6.
盐胁迫下柚实生苗生长、矿质营养及离子吸收特性研究   总被引:8,自引:1,他引:7  
以坪山柚为材料,对盐胁迫下实生苗生长、矿质营养及离子吸收特性进行了研究。结果表明,沙培30d,80~200mmol/L盐胁迫,随盐浓度提高,坪山柚实生苗株高、叶面积、地上部干重和根部干重明显降低。溶液培养8d,坪山柚实生苗地上部及根Na+、Cl-含量随盐浓度的增加而增加,根及地上部K+、Ca2+、Mg2+以及P和Mn含量下降,Fe、Zn、Cu含量的变化因器官而异。其中,地上部Fe含量对盐胁迫敏感,可作为柚耐盐性鉴定指标。40mmol/L盐胁迫,坪山柚地上部K+/Na+、Ca2+/Na+、Mg2+/Na+值均显著下降,且Mg2+/Na+值+/Na+值>1;浓度≥160mmol/L盐胁迫,K+/Na+值+吸收、运转效率比Cl-高。  相似文献   

7.
不同土壤盐分条件下新疆杨可溶性盐离子含量变化的研究   总被引:2,自引:0,他引:2  
对2种含盐量土壤条件下新疆杨可溶性盐离子含量的研究结果表明,退水渠土壤各盐离子含量均高于灌渠土壤,且二者除HCO3-和K 外,其余盐离子含量差异显著;但2种含盐量土壤同龄新疆杨地上部可溶性盐离子含量差异不显著,仅根内Cl-、Mg2 、Na 和K 含量差异显著,说明新疆杨对土壤中较高浓度盐离子有一定排斥作用,并将对树木产生毒害的Cl-、Na 控制在根系中,限制其向地上部输送;新疆杨根系对SO24-和Ca2 有较强的选择吸收性,并将过多的SO2-和Ca2 排除其体外,而对Cl-、Mg2 和Na 的选择吸收性较小。  相似文献   

8.
为揭示滨海盐碱地造林树种对土壤盐分组成变化及树体内盐离子的吸收、运移的影响,采用野外取样与室内分析测试相结合的方法,定量研究了8个盐碱地生态造林树种不同部位(叶、枝、皮、根)及相应林下土壤可溶性盐离子含量,结果表明:对照空地与8个树种及林下土壤中均无CO2-3存在,造林可明显改变土壤中Na+、Cl-、SO2-4、HCO-3等可溶性盐离子的含量,降低土壤全盐含量,不同树种对土壤平均含盐量的降低状况表现为柽柳白蜡杨树桑树刺槐紫穗槐榆树冬枣。不同树种对K+、Na+、Ca2+、Mg2+的吸收选择性系数呈现SK,NaSCa,NaSMg,Na,整体上不同树种对K+具有很强的吸收选择性,Na+被动吸收及在体内的分布表现了树种间的耐盐机制差异,不同树种对Ca2+的吸收选择性都略高于Mg2+。8个树种运输选择性系数RS各不相同,导致树体内各可溶盐离子的分布不同,不同树种各器官中K+、Ca2+、Mg2+的浓度均呈叶部较高。  相似文献   

9.
硝态氮对盐胁迫下囊果碱蓬幼苗根系生长和耐盐性的影响   总被引:8,自引:0,他引:8  
在溶液培养条件下,设计了4个盐分(1,150,300或450 mmol/L NaCl)和3个氮素(0.05,5或10 mmol/L NO3--N)水平,研究了盐、氮及其互作对囊果碱蓬(Suaeda physophora Pall.)幼苗的离子吸收、氮营养状况、根系形态特征及耐盐性的影响。结果表明,与低盐或低氮相比,增加盐分或氮水平显著增加了囊果碱蓬根部的干重、根系的侧根长、表面积、总吸收面积和活跃吸收面积;且这些根系的形态指标与地上部的离子及氮的累积存在显著的正相关。高盐胁迫下增加氮营养,显著增加了地上部Na+、NO3-、有机氮的含量和硝酸还原酶的活性;降低了Cl-和K+的含量。高盐胁迫下,硝态氮的增加促进了囊果碱蓬幼苗根系的生长,增加了地上部有机氮、NO3-和Na+的累积,改善了植株的营养状况和渗透调节,从而提高了囊果碱蓬的耐盐能力。  相似文献   

10.
外源氮对NaCl胁迫下库拉索芦荟生理特性的影响   总被引:4,自引:0,他引:4  
温室盆栽条件下,研究了外施不同浓度硝酸铵对200 mmol/L NaCl 胁迫下库拉索芦荟叶片离子含量、质膜透性、丙二醛含量及脯氨酸和可溶性糖积累的影响。结果表明,外施不同浓度NH4NO3(3.75 ~18.75 mmol/L)能够显著增加200 mmol/L NaCl胁迫下植株干重,明显促进芦荟叶片脯氨酸和可溶性糖积累,提高叶片K+、Ca2+含量,抑制叶片对Na+、Cl-的吸收;同时促进K+ 和Ca2+ 向相对幼嫩叶片、Na+ 和Cl-向相对成熟叶片中的积累。外施氮显著降低盐胁迫下叶片细胞质膜透性和丙二醛含量。各项指标变化表明,外施11.25和15 mmol/L NH4NO3对盐胁迫下芦荟生理特性的调控作用较好;外源氮缓解芦荟盐害与氮促进盐胁迫下叶片离子选择吸收、增加有机渗透物质积累及维持植株体内养分平衡有关。  相似文献   

11.
The effects of the interaction between sodium chloride, nitrate, and concentrations on growth and internal ion content of faba bean (Vicia faba L.) plants were studied, to understand the relationship between the above parameters and salt tolerance. Increased salinity substantially reduced the dry weight of roots and shoots and increased the root/shoot biomass ratio. Additional nitrate‐N considerably moderated the salinity effects on these parameters. The promotive effects of nitrate‐N were more pronounced on shoot dry weight. These results suggest that an exogenous supply of nitrate‐N would improve the vegetative growth of V. faba plants by moderating the suppresive effects of salinity. The evolution of the root and shoot content in potassium (K), sodium (Na), magnesium (Mg), calcium (Ca), and nitrogen (N) was monitored during vegetative growth. A high correspondence between total N and Ca content was found. The acquisition of Ca and K in response to salt and nitrate was similar in shoots and roots, whereas Mg uptake showed notable differences in the two organs. In salt‐affected plants, the roots were found to be high in accumulated Na while the shoots exhibited the lowest Na concentration. Potassium accumulation was higher in the shoots. In this way, there was an antagonistic effect between Na and K uptake. Analyses of the nutrient contents in plant organs have provided a data base on salt‐tolerance mechanisms of V. faba plants.  相似文献   

12.
The effect of salinity on growth response, nitrogen (N) fixation and tissue mineral content was investigated for four legumes: faba bean (Vicia faba L), pea (Pisum sativum L), soybean (Glycine max L), and common bean (Phaseolus vulgaris L). Plants were grown in a vermiculite culture system supplied with a N‐free nutrient solution with the addition of 0, 50, and 100 mM NaCl. Plants were harvested at the beginning of the flowering period and the dry weights of shoots and roots and acetylene reduction activity (ARA) were evaluated at the same time plant tissues were analysed for N, potassium (K), calcium (Ca), magnesium (Mg), and sodium (Na) contents.

The depressive effect of saline stress on ARA of nodules was directely related to the salt induced decline in dry weight and N content in shoots. Growth inhibition by NaCl treatments was greater for the pea than for other legumes, whereas the soybean was the most salt‐tolerant Saline stress also affected the N content in shoots and roots. In general the N content accumulated in the shoot and Na in the roots of the four legumes tested, while K accumulated both organs. The acquisition of other macronutrients differed according to the legume species. The legumes most sensitive were P. sativum and V. faba which accumulated Ca in shoot and Mg both in the shoot and the roots. On the contrary, in G. max and P. vulgaris, the two most salt tolerant legumes, accumulated Mg in the roots and Ca in both vegetative organs. Our results suggest a relationship between the salt‐tolerant range in legumes and the macronutrient accumulation in vegetative organs.  相似文献   

13.
ABSTRACT

The effect of salinity (1.5, 3.0, 4.5, or 6.0 dS m? 1) on ion concentrations [magnesium (Mg), calcium (Ca), potassium (K), sodium (Na), and chloride (Cl)] of one-year-old ‘Hass’ avocado (Persea americana Mill.) trees on one of three rootstocks [‘Duke 7’ (D7), ‘Toro Canyon’ (TC), or ‘Thomas’ (TH)] was investigated. Concentrations of Mg decreased in roots, stems, and older leaves with increasing substrate salinity. Salinity had no effect on Ca concentration of the trees. Potassium concentrations decreased in roots of all trees and stems of trees on TH. Potassium concentrations either remained unchanged or increased at salinity levels of 3.0 dS m? 1 and above in leaves and buds of all trees. Sodium increased in roots and woody organs in trees on all rootstocks. Leaf Na concentrations increased with salinity in trees on D7 and TH, but not TC. Chloride increased in all organs of all trees with increasing salinity, but to the greatest extent in trees on TH and to the least extent in trees on TC. At high substrate salinity concentrations, leaves of trees on TH rootstock had the highest leaf concentrations of Na and Cl, and the highest Na:K ratios. Sodium and chloride concentrations were correlated with necrosis in older leaves of TH, but less so in leaves of trees on TC or D7. Based on percent necrosis in older leaves with increased salinity, trees on TH performed poorest, whereas trees on TC exhibited the greatest salt tolerance. Leaf necrosis was consistently observed at Cl concentrations of 4 mg g? 1 or more, and at Na:K ratios of 0.01 or more in older leaves. Chloride concentration and Na:K ratio in older leaves appears to be a useful marker for salinity tolerance screening in avocado rootstocks. The relative tolerance of the various rootstocks appeared to be due primarily to their ability to exclude Na and Cl from the leaves.  相似文献   

14.
Alfalfa (Medicago sativa L.) yield and nutrient contents may be affected under salinity condition. Thus, this experiment was conducted to determine the effect of three salinity levels (60, 120, and 180 mM NaCl) on shoot and root dry weights, and mineral contents of three alfalfa cultivars. With the increasing salinity levels sodium (Na) and magnesium (Mg) contents increased; but potassium (K), nitrogen (N), phosphorous (P), calcium (Ca), zinc (Zn), and copper (Cu) contents and root and leaf weights decreased; however, changes in these traits depended on cultivar and salinity level. However, Rehnani, a tolerant cultivar, had the lowest Na and Mg contents and the highest K, N, P, Ca, Zn, and Cu contents and dry weights under all of the salinity levels. Moreover, leaf dry weight and leaf P content had the highest correlation with salt tolerance suggesting that these traits may be used as a marker for selecting salts that are tolerant among genotypes in alfalfa.  相似文献   

15.
Two experiments were conducted to determine if improved nutrient uptake increases salinity tolerance of cotton (Gossypium hirsutum L.). A transgenic cotton line (CMO3) with increased salt tolerance and its wild line (SM3) were grown in pots containing substrate (peat:vermiculite = 1:1, v/v) in the first experiment, while cotton (‘SCRC 28’) was cultured in hydroponics with a split-root system in the second experiment. Contents of essential nutrient elements and Na+ in plant tissues, leaf photosynthesis (Pn) and chlorophyll (Chl) concentration and plant biomass were determined after salinity [sodium chloride (NaCl)] treatment in both experiments. In the first experiment, salinity stress with 150 mM NaCl reduced plant biomass and photosynthesis (Pn) of both SM3 and CMO3 compared with their non-stressed controls, but the CMO3 suffered significantly lower reductions than SM3, suggesting an increased salinity tolerance of CMO3 relative to SM3. Total uptake and contents of main nutrient elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), copper (Cu), and zinc (Zn)] in CMO3 were higher than those in SM3. Also, less sodium (Na+) accumulation and lower extreme ratios of Na/N, Na/P, Na/K, Na/Ca, Na/Mg, Na/Fe, Na/Mn, Na/Cu, and Na/Zn were observed in CMO3 than in SM3. Increased salt tolerance in transgenic AhCMO cotton was probably attributed to its superior nutrient uptake compared with SM3. In the second experiment, the non-stressed root half fed with moderate level of nutrient solution and salt-stressed half fed with low level of nutrient solution (CMN/SLN) exhibited higher salinity tolerance than salt-stressed root half fed with moderate level of nutrient solution and non-stressed root half fed with low nutrient solution (CLN/SMN). Plants absorbed more nutrients but less Na+ under CMN/SLN than CLN/SMN. The overall results suggest that improved nutrient uptake played an important role in the enhanced salt tolerance of cotton.  相似文献   

16.
This study assesses the nutritional behavior of the new citrus rootstocks Forner-Alcaide no.5 (FA-5) and Forner-Alcaide no.13 (FA-13) under saline conditions compared to that of their parents, Cleopatra mandarin (CM) and Poncirus trifoliata (PT). Eighteen month-old plants grafted with Valencia orange scions were used in the experiment. The plants were grown in a greenhouse and irrigated over an eight-week period with nutrient solutions to which different amounts of sodium chloride (NaCl) had been added, namely 0, 20, 40 and 60 mM. Relative growth and the uptake of major mineral elements [nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)] were then determined. It was noted that the reduction in relative growth caused by salt treatment was greater in plants grafted on PT than those on FA-13, FA-5 and CM. Increasing the salt level in the growth medium reduced the absorption of the above mineral elements in all scion-rootstock combinations. However, this decrease was generally more marked in plants grafted on PT than in those on CM and FA-5. Plants on FA-13 showed an intermediate behavior. Positive correlations were found between growth and mineral element uptake by salt treated plants. Nutrient uptake was also plotted against chloride (Cl) and sodium (Na) concentrations in leaves and roots at increasing salt levels. This showed that N absorption was closely correlated (inversely) with Cl content in leaves, whereas K, Ca and Mg uptakes were correlated (inversely) with Na concentration in roots. This suggests that the accumulation of saline ions impacts growth and nutrient uptake by citrus plants.  相似文献   

17.
Growth, ion balance, water relations and leaf photosynthesis of canola (Brassica napus L., cv. Excel) and wild mustard (Brassica kaber L. C. Wheeler) grown under a mixture of sodium and magnesium sulphate salts were examined using a hydroponic system in a growth chamber. Wild mustard was less salt tolerant than canola, based on the growth responses. Salinity caused large accumulation of sodium (Na) and magnesium (Mg) ions, but reduced calcium (Ca) and potassium (K) concentrations in the shoots and roots. Water potential, osmotic potential, transpiration, stomatal conductance and hydraulic conductance decreased to a greater extent in canola than in wild mustard, indicating salinity imposed a smaller osmotic effect on the wild species. Calcium addition improved the growth of wild mustard more than canola but it had no effect on water relations. The growth reduction in these species under salt stress resulted from a combination of ion toxicity, insufficient nutrient ion availability and altered water relations. Supplemental Ca improved growth by reducing Mg and increasing Ca content in plant tissues, ameliorating salinity‐associated ion toxicity to photosynthesis, and possibly through an indirect effect on cell growth.  相似文献   

18.
The effects of different levels of arsenic (As) and salinity on bean plant (Phaseolus vulgaris L., cv. Buenos Aires) nutrition were investigated. We studied the processes of absorption and accumulation of macronutrient elements: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg). The experiment was performed in soilless culture at two levels of As: 2 and 5 mg AsL‐1 (added as sodium arsenite, NaAsO2), and three saline levels [only sodium chloride (NaCl) was added]: 1, 2, and 4 dS‐m‐1. Sodium arsenite and NaCl significantly affected macronutrients allocation within bean plant at concentration levels used in this study. Arsenite depressed K, Na, and Mg concentrations in root, whereas root N, and Ca levels were increased. Nitrogen, P, K, and Na concentrations were significantly higher in As‐stressed plants compared with controls. The addition of NaCl increased Ca concentration in roots and decreased that of K. Salinity tended to increase leaf concentrations of K, Na, Ca, and Mg; whereas leaf N and P levels decreased with increasing salinity.  相似文献   

19.
李娟  周立军 《土壤》2020,52(3):645-650
为了解在成龄胶园间作的五指毛桃根际与非根际土壤及其根中主要中、微量元素含量情况,测定了实验区根际与非根际土壤各30个和对应五指毛桃根的钙、镁、铁、锰、铜和锌含量,分析了两者之间的关系,并评价了根际与非根际土壤中、微量元素丰缺状况。结果表明,非根际土壤钙、镁、铁、锰含量的平均值都高于根际土壤的,而铜、锌含量的平均值都低于根际土壤的。土壤钙、镁含量80%以上处于缺水平,而铁、锰含量处于丰或很丰水平,铜和锌含量处于适中水平。五指毛桃根际与非根际土壤中、微量元素存在空间上的广泛变异。五指毛桃根中、微量元素的平均值从大到小的排序是钙>镁>锰>铁>锌>铜。土壤中、微量元素与五指毛桃根中相对应的中、微量元素的相关性不强,且表现复杂。本研究结果揭示,在成龄胶园间作五指毛桃应当适量施用钙肥、镁肥和喷施一些铜元素叶面肥,并实行科学施肥,减少养分淋失。  相似文献   

20.
The effect of three levels of salinity (2.0,4.0, and 8.0 mS/cm) on growth and ion composition of tomato and cucumber seedlings was examined with and without addition of 7.4 meq/L calcium chloriode (CaCl2). The corresponding sodium/calcium (Na/Ca) ratio of the irrigation solution were 4.0 and 1.8 at salinity level 4.0 mS/cm, and 12 and 4.8 at salinity level 8.0 mS/cm. Seedlings growth of tomato and cucumber was generally reduced with increasing salinity level. Cucumber was more salt‐sensitive than tomato. Shoot and root dry weight of cucumber was increased by decreasing Na/Ca ratio at 4.0 mS/cm salinity. Sodium and chloride (Cl) accumulation was increased and Ca was decreased in salinized plants. Reducing Na/Ca ratio under saline condition reduce the accumulation of Na in tomato roots. The effect of salinity on the uptake of nitrogen (N), phosphorus (P), potassium (K), Na, Ca, chloride (Cl), iron (Fe), zinc (Zn), manganese (Mn), and copper (Cu) in the root and shoot was also determined.  相似文献   

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