首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 31 毫秒
1.
This study aimed at investigating mechanisms of salt tolerance and ionic relations of chickpea (Cicer arietinum L.) cultivars with different nitrogen (N) sources. Two resistant genotypes, ILC‐205 and ILC‐1919, were subjected to four levels of salinity (0.5, 3.0, 6.0, and 9.0 dS m‐1). Nitrogen sources consisted of inoculation with two resistant Rhizobium strains, CP‐29 and CP‐32, mineral N additions, and no N application. Data was collected on root and shoot contents of sodium (Na+) chlorine, (Cl‐,) and potassium (K+), and shoot to root Na+ratio, as well as shoot K+ to Na+ ratio. Salinity affected shoot Na+ and Cl‐contents, but nodulating plants had higher shoot Na+ contents than plants supplied with mineral N. Shoot to root Na+ ratios were lower in the mineral N treatment than in nodulating treatments at 3.0 dS m‐1, indicating that root compartmentalization and shoot exclusion were only possible at low salinities. Potassium levels of nodulating plant shoots were lower than those of non‐nodulating plants only at low salinities. N‐source significantly affected shoot K+/Na+ ratio, with nodulating plants having lower ratios than non‐nodulating plants, indicating that rhizobial infection or nodule formation may lead to salt entry curtailing the selective ability of chickpea roots.  相似文献   

2.
Fertigation with KNO3 as a means of reducing salinity hazards was tested with peanut (Arachis hypogaea) plants grown on dune sand, resulting in a reduction of plant growth and yield. The objective of this work was to study the interactions between N, K+ and NaCl as well as the effects of the NH4 +/NO3 ‐ ratio on vegetative and reproductive growth. Wheat (Triticum aestivum L.) plants were grown in polyethylene pots with fine calcareous dune sand with different proportions of NH4 + and NO3 ‐, under saline (60 mM NaCl) and non‐saline conditions. Three replicates were harvested at the beginning of flowering, and one was grown to grain maturity. NaCl reduced shoot dry weight in all the treatments. Increasing the NH4 + proportion in the total of 6 mM N in the nutrient solution, increased shoot dry weight, did not change nitrogen concentration in the dry mass but increased P percentage, either with or without 60 mM NaCl. The number of tillers produced in each treatment was correlated with dry matter yield. The effect of the NH4 +/NO3 ‐ ratio may be explained by alteration of the cation‐anion balance on the nutrient uptake by roots, which lowered pH of the nutrient solution with increasing NH4 + concentration, by alteration of the cation‐anion balance on the nutrient uptake by roots, which lowered pH of the nutrient solution with increasing NH4 + concentration.  相似文献   

3.
Olive (Olea europaea L cv. Leccino and cv. Frantoio) plants grown in aeroponic cultivation system were supplied with Hoagland solutions containing 0 and 150 mM NaCl for 4 weeks. Sodium (Na+), chloride (Cl‐), and potassium (K+) concentration was measued on 15‐day‐old leaves and K+/Na+ selectivity ratio was calculated. Plant water relations were estimated on the same leaves by measuring leaf bulk water and osmotic potentials, and by calculating leaf turgor pressure. Root and leaf tissues were also analysed for lipid composition, estimating free sterol (FS), glycolipid (GL) and phospholipd (PL) content. The salt‐sensitive Leccino accumulated more Na+ and Cl‐ in the leaves and showed a lower K+/Na+ selectivity ratio than the salt‐tolerant Frantoio. The FS/PL ratio and the content of GL (namely mono‐galactosyldiglyceride, MGDG) in the roots were related to the salt accumulation in the shoot. Salinity‐induced changes on root lipids were more important in Frantoio than in Leccino, indicating the specific role of the roots in salt exclusion mechanisms. Conversely the effect of salinity on leaf lipid composition was more important in the leaves of the salt‐sensitive Leccino.  相似文献   

4.
Maize plants (Zea mays L. cv. Pioneer 3906) were grown in hydroponics with four different NaCl treatments (control, 50, 100, 150 mM NaCl). Nitrogen (N) was supplied as 2 mM Ca(NO3)2 in the fully concentrated nutrient solution. Plants of half of the pots were treated with additional 1 mM NH4NO3 2 d after start of the NaCl application. After 23 d, the maize plants were harvested and contents and concentrations of nitrate, reduced N as well as chloride were determined in shoots and roots. With increasing NaCl stress net nitrate uptake and net root‐to‐shoot translocation of total N decreased significantly. Under salt stress, decreased nitrate concentrations in shoots probably caused substrate limitation of nitrate reductase. However, the concentrations of reduced N in shoots were not affected by salt stress and no N deficiency was observed. Additional N application to the 100 and 150 mM NaCl treatments did not improve plant growth. A Cl?/NO antagonism was only weakly pronounced, probably because of the Cl? exclusion ability of maize. Thus, although net uptake and net translocation of total N were markedly decreased by NaCl application, the smaller maize plants nevertheless took up enough N to meet their demand pointing to other growth‐limiting factors than N nutrition.  相似文献   

5.
There exists a great variability among plant species regarding their sensitivity and resistance to high salinity in soil, and most often this variability is related with the ability of a particular plant species to regulate ion homeostasis and transport. In this study, we have investigated the effects of NaCl on growth rate, water status, and ion distribution in different cells and tissues of two succulent plants, Aloe vera and Salicornia europaea. Our results showed that the growth of A. vera seedlings was significantly decreased in response to salinity. However, the growth of S. europaea seedlings was greatly stimulated by high concentrations of NaCl. Under saline conditions, S. europaea seedlings maintained K+ and Ca2+ uptake in roots and showed a higher root‐to‐shoot flux of Na+ and Cl– as compared to A. vera. Despite great accumulation of Na+ and Cl– in photosynthetically active shoot cells in S. europaea, its growth was enhanced, indicating S. europaea is capable of compartmentalizing salt ions in the vacuoles of shoot cells. Aloe vera seedlings, however, showed a low transport rate of Na+ and Cl– to leaves and suppressed uptake of K+ and Ca2+ in roots during NaCl treatment. Our results also implicate that A. vera may be able to accumulate Na+ and Cl– in the metabolically inactive aqueous cells in leaves and, as a result, the plant can survive and can maintain growth under saline conditions.  相似文献   

6.
The different responses of two populations of Suaeda salsa (Linn.) Pall. (saline seepweed) from an intertidal zone and a saline inland zone to salinity [1 or 500 mM sodium chloride (NaCl)] and nitrogen [N; 0.05, 1, or 10 mM nitrate (NO3 ?)‐N] were investigated. Greater NO3 ?‐N supply (10 mM) increased shoot dry weight for the two populations of S. salsa, especially for S. salsa from the saline inland zone. Greater NO3 ?‐N supply (10 mM) increased the concentrations of chlorophyll and carotenoid in leaves and the NO3 ? and potassium (K+) concentrations in shoots for both populations. Greater NO3 ?‐N supply (10 mM) increased shoot Na+ in S. salsa from the intertidal zone. In conclusion, S. salsa from the saline inland zone is more responsive to NO3 ?‐N supply than the intertidal population. Greater NO3 ?‐N supply can help the species, especially the intertidal population, to grow and to mediate ion homeostasis under high salinity.  相似文献   

7.
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：7，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   

8.
Tobacco plants (Nicotiana tabacum L. cv NC82) were supplied with (NH4)2SO4, or NH4Cl at root‐zone pH of 6.0 and 4.5 in hydroponic culture for 28 days. Dry matter accumulation, total N and C content, and leaf area and number were not affected by the NH4 + source or root‐zone pH. Plants supplied with NH4C1 accumulated up to 1.2 mM Cl g DW‐1, but accumulated 37% less inorganic H2PO4 ‐ and 47% less SO4 2‐ than plants supplied with (NH)2SO4. The large Cl‐ accumulation resulted in NH4C1 –supplied plants having a 31% higher inorganic anion (NO3 ‐, H2, PO4 ‐, SO4 2‐, and Cl‐) charge. This higher inorganic anion charge in the NH4C1‐supplied plants was balanced by a similar increase in K+ charge. Plants supplied with NH4Cl accumulated greater concentrations of Cl‐ in leaves (up to 5.1% of DW) than plants supplied with (NH4)2SO4 (less than ‐% DW). Despite the high Cl‐ concentration of leaves in NH4Cl supplied plants, these plants showed no symptoms of Cl‐ toxicity. This demonstrates that toxicity symptoms are not due solely to an interaction between high Cl‐ concentration in tissue and NH4 + nutrition. The increase in root‐zone acidity to pH 4.5 from 6.0 did not induce toxicity symptoms.  相似文献   

9.
The influence of nitrogen (N) forms and chloride (Cl) on solution pH and ion uptake in the hydroponic culture of Ageratum houstonianum [ammonium (NH4 +)‐tolerant] and Salvia splendens (NH4 +‐sensitive) for a period of 216 hours was investigated. The pH of the hydroponic solution (initially 6.50) containing either NH4 + or NH4 ++nitrate (NO3 ‐) was drastically lowered (3.08), whereas that of the same solution containing NO3 ‐ was raised (7.74). Solution pH changed more by ageratum than by salvia. The solution Cl‐ concentration did not influence pH significantly. However, addition of Cl‐ in the solution lowered transpiration rate in both NH4 + and NO3 ‐ treatments. Total N uptake was the greatest in the NH4 + + NO3 ‐ treatment and the lowest in the NO3 ‐treatment. In the NH4 + + NO3 ‐ treatment, NO3 ‐ uptake was suppressed by NH4 + (to about 50%), while NH4 + uptake was not affected by NO3 ‐. The rate of Cl‐ uptake was the lowest in the NH4 + treatment, but was similar in the NH4 + + NO3 ‐ and NO3 ‐ treatments. Uptake of potassium (K+), dihydrogen phosphate (H2PO4 ‐), sulfate (SO4 ‐2), manganese (Mn+2), and zinc (Zn+2) was significantly enhanced in the NH4 + treatment. The uptake rate of calcium (Ca+2) and magnesium (Mg+2) was the highest in the NO3 ‐ treatment. Absorption of copper (Cu+2) and boron (B) was not affected by N source. Ion uptake was more stable in the solution containing both NH4 + and NO3 ‐ than in the solution containing either NH4 + or NO3 ‐. The uptake rate of total N, NH4 +, NO3 ‐, Mn+2, Cu+2, and Zn+2 was higher, whereas that of Cl‐ and molybdenum (Mo) was lower in ageratum than in salvia. Amounts of total anion (TA) and total cation (TC) absorbed, the sum of TC and TA, and the difference between TC and TA (TC‐TA) were affected by N source, Cl‐ level, and their interactions. The NO3 treatment, as compared to the NH4 + or the NH4 + + NO3 ‐treatment, reduced total cation and anion uptake while increasing TC‐TA, especially in the absence of Cl‐. Plant tissue ion contents were also affected by N source and Cl‐ level.  相似文献   

10.
Salinity and low nitrogen availability are important growth‐limiting factors for most plants. Our objective was to assess the influence of nitrogen (N) and salt levels on the growth and mineral nutrition of three forage grasses of varying salt resistance which are widely found in Tunisian salt lands, Aeluropus littoralis, Catapodium rigidum, and Brachypodium distachyum. Their response to salt and N interaction has not been studied and further investigations are necessary. Twenty day–old plantlets were hydroponically cultivated in Hewitt's nutrient solution. Half the plants were then exposed to 100 mM NaCl and the other half to no NaCl, and N was supplied at 0.5 or 5.0 mM N as NH4NO3. Plants were harvested after 60 d growth. Saline treatment (100 mM NaCl) decreased growth of B. distachyum (a relatively salt‐sensitive plant), but no significant effect was noted for A. littoralis (a relatively salt‐resistant plant) in both low– and high–N availability treatments. However, the effect of 100 mM NaCl on growth of C. rigidum (a moderately salt‐resistant plant) depended on N level. Increasing N availability and NaCl did not influence phosphate, sulfate, calcium, and magnesium concentrations in both A. littoralis and C. rigidum, but increased N supply reduced shoot sodium and chloride (Cl–) accumulation. Potassium acquisition in A. littoralis and C. rigidum plants was severely depressed by increasing N availability under saline and nonsaline conditions, respectively. In these species, the increase of nitrate accumulation via N was attenuated by salinity. In contrast, total N content and allocation toward shoots were enhanced in these conditions, especially in A. littoralis, the most resistant species. It appears that increasing N availability at moderate salt levels has a beneficial effect on growth of species with high and moderate salt resistance, but not on species with low resistance to salinity.  相似文献   

11.
【目的】土壤盐碱化是制约农作物产量的主要因素之一,盐胁迫影响养分运输和分布,造成植物营养失衡,导致作物发育迟缓,植株矮小,严重威胁着我国的粮食生产。在必需营养元素中,氮素是需求量最大的元素,NO-3和NH+4是植物吸收氮素的两种离子形态。植物对盐胁迫的响应受到不同形态氮素的调控,研究不同形态氮素营养下植物的耐盐机制对提高植物耐盐性及产量具有重要的意义。【方法】本文以喜硝植物油菜(Brassica napus L.)和喜铵植物水稻(Oryza sativa L.)为试验材料,采用室内营养液培养方法,研究了NO-3和NH+4对Na Cl胁迫下油菜及水稻苗期生长状况、对Na+运输和积累的影响,以对照与盐胁迫植株生物量之差与Na+积累量之差的比值,评估Na+对植株的伤害程度。【结果】1)在非盐胁迫条件下,硝态氮营养显著促进油菜和水稻根系的生长;盐胁迫条件下,油菜和水稻生物量均显著受到抑制,Na Cl对供应铵态氮营养植株的抑制更为显著。2)盐胁迫条件下,两种供氮形态下,油菜和水稻植株Na+含量均显著增加,硝态氮营养油菜叶柄Na+显著高于铵态氮营养,叶柄Na+含量/叶片Na+含量大于铵营养油菜,硝态氮营养水稻根系Na+含量显著低于铵营养,地上部则相反。3)铵营养油菜和水稻Na+伤害度显著高于硝营养植株。4)盐胁迫条件下,硝态氮营养油菜地上部和水稻根系K+含量均显著高于铵态氮营养。5)盐胁迫条件下,硝营养油菜和水稻木质部Na+浓度,韧皮部Na+和K+浓度及水稻木质部K+浓度均高于铵营养植株。【结论】与铵营养相比,硝营养油菜和水稻具有更好的耐盐性。硝态氮处理油菜叶柄Na+显著高于铵态氮处理,能够截留Na+向叶片运输。同时,供应硝态氮营养更有利于油菜和水稻吸收K+,有助于维持植物体内离子平衡。盐胁迫下,硝营养油菜和水稻木质部Na+浓度,韧皮部Na+和K+浓度及水稻木质部K+浓度均高于铵营养植株,表明硝态氮营养油菜和水稻木质部-韧皮部对离子有较好的调控能力,是其耐盐性高于铵营养的原因之一。  相似文献   

12.
High concentrations of bicarbonate (HCO? 3) cause alkalinity of irrigation water and are associated with suppression in plant growth and micronutrient deficiencies, such as iron (Fe) and zinc (Zn). Because reports indicate that the deleterious effects of alkalinity may be counteracted partially by supplementary potassium (K+) or ammonium (NH4 +) an experiment was designed to evaluate the response of bean plants (Phaseolus vulgaris L.) grown in high alkalinity conditions to varying proportions of NH4 +, K+, or sodium (Na+) (as a potential substitute for K+). Plants established in a growth chamber were grown in hydroponics for 21 days in solutions containing 5 mM HCO? 3 and a total of 5 mM of a mixture of NH4 +, K+, and Na+. The proportions of NH4 +, K+, and Na+ were designed according to mixture experiment methodology. Total N in all the mixture treatments was maintained at 10 mM by using nitrate (NO? 3)-N, thus the NH4 +:NO? 3 ratio varied according to the proportion of NH4 + in the mixtures. Alkalinity caused suppression in plant growth and chlorophyll concentration in the younger leaves, whereas excessive NH4 + was associated with leaf scorching and decreased leaf expansion. High proportions of K+ alleviated alkalinity symptoms and produced higher shoot and root dry mass provided that NH4 + was included in the mixture. However, a proportion of NH4 + higher than 0.333 in the mixture (>1.66 mM NH4 +) induced toxicity. The highest shoot dry mass occurred if the NH4 +:NO? 3 ratio was 0.19:0.81 and the NH4 +:K+:Na+ proportion was 0.38:0.38:0.24 (1.9 mM NH4 + + 1.9 mM K+ + 1.2 mM Na+). Thus, an improvement in plant growth is achieved when NH4 +, K+, and Na+ are blended together, in spite of the high alkalinity treatment imposed. Optimum NH4 + was associated with a decrease in solution pH and an increase in shoot Fe and Zn concentration.  相似文献   

13.
The interactive effects of salinity and potassium (K+) availability on biomass production, water status, and ionic composition were investigated in Hordeum maritimum, an annual grass growing natively on saline soils. Plants were grown for 7 weeks on Hewitt nutrient solution supplied with NaCl (0, 100, 150, 200, and 300 mM) combined with low (0.232 mM) or high (5.8 mM) K+ levels. Independent of potassium availability, dry matter of both roots and shoots decreased consistently with increasing NaCl levels in the culture medium, in association with a significant reduction of the shoot water content. This salt‐induced growth reduction did not result from a restriction of K+ nutrition, since H. maritimum expressed similar growth under both low and high K+ supply. NaCl decreased shoot K+ concentrations. This effect was more pronounced in plants grown at high K+ supply than in plants grown at low K+ supply. This result suggests that the absorption systems were strongly selective for K+, and that this selectivity was enhanced by salt.  相似文献   

14.
Maize (Zea mays L.) plants in the early stage of development were treated with 80 mM sodium chloride (NaCl) with or without supplemental calcium (Ca2+) (8.75 mM) for a seven day period. The effects of salinity on dry matter production and shoot and root concentrations of sodium (Na+), Ca2+, and potassium (K+) were measured for seven Pioneer maize cultivars. Salinity significantly reduced total dry weight, leaf area, and shoot and root dry weight below control levels. For all seven cultivars, Na+concentrations were reduced and leaf area was significantly increased by supplementing salinized nutrient solutions with 8.75 mM calcium chloride (CaCl2). The two cultivars with the lowest shoot and root Na+ concentrations under NaCl‐salinity showed the greatest increases in total, shoot and root dry weights with the addition of supplemental Ca. Shoot fresh weight/dry weight ratios for all cultivars were decreased significantly by both salinity treatments, but supplemental Ca2+ increased the ratio relative to salinity treatments without supplemental Ca. Root fresh weight/dry weight ratios were decreased only by salinity treatments with supplemental Ca. With NaCl‐salinity, cultivars which had lower shoot and root Na+ concentrations were found to be more salt sensitive and had significantly lower amounts of dry matter production than those cultivars which had higher shoot and root Na+ concentrations. It was concluded that Na+ exclusion from the shoot was not correlated with and was an unreliable indicator of salt tolerance for maize.  相似文献   

15.
Two varieties of durum wheat (Om Rabiaa and Karim), were analyzed and evaluated in the presence of increasing doses of NaCl (0, 100, 200 and 300?mM) in which we added different concentrations of nitrate (0.1, 3, 10?mM). The data obtained showed that presence of NaCl in the culture medium induces the increase of the salt accumulation levels (Na+, Cl?) and reduces the levels of K+ and NO3? in the cultivar Om Rabiaa. In Karim variety, ions that have been heavily accumulated following exposure to NaCl are Na+ and K+ while low levels of NO3? and Cl? have been detected. Those findings highlight the difference in the salinity tolerance of durum wheat cultivars also depending on nitrogen (N) availability, Karim cultivar being less sensitive to NaCl treatment than Om Rabiaa. These data also suggested a relationship between salt tolerance capacity and enhancement of nitrogen and carbon metabolisms enzyme activity.  相似文献   

16.
Fertilization with nitrogen (N) or phosphorus (P) can improve plant growth in saline soils. This study was undertaken to determine wheat (Triticum aestivum L; cv Krichauff) response to the combined application of N and P fertilizers in the sandy loam under saline conditions. Salinity was induced using sodium (Na+) and calcium (Ca2+) salts to achieve four levels of electrical conductivity in the extract of the saturated soil paste (ECe), 2.2, 6.7, 9.2 and 11.8?dS?m?1, while maintaining a low sodium adsorption ratio (SAR; ≤1). Nitrogen was applied as Ca(NO3)2?·?4H2O at 50 (N50), 100 (N100) and 200 (N200)?mg?N?kg?1 soil. Phosphorus was applied at 0 (P0), 30 (P30) and 60 (P60)?mg?kg?1?soil in the form of KH2PO4. Results showed that increasing soil salinity had no effect on shoot N or P concentrations, but increased shoot Na+ and chlorine ion (Cl?) concentrations and reduced dry weights of shoot and root in all treatments of N and P. At each salinity and P level, increasing application of N reduced dry weight of shoot. At each salinity and N level P fertilization increased dry weights of shoot and root and shoot P concentration. Addition of greater than N50 contributed to the soil salinity limiting plant growth, but increasing P addition up to 60?mg?P?kg?1 soil reduced Cl? absorption and enhanced the plant salt tolerance and thus plant growth. The positive effect of the combined addition of N and P on wheat growth in the saline sandy loam is noticeable, but only to a certain level of soil salinity beyond which salinity effect is dominant.  相似文献   

17.
The reduction in tiller number is a major reason for a decrease in grain yield of wheat. Thus, we hypothesize that the limiting growth of tillering of wheat plant under saline conditions may be due to a different distribution of ions among tillers, which may be tested by tiller removal. Two contrasting spring wheat (Triticum aestivum L.) genotypes were subjected to five levels of detillering treatments under saline or non-saline conditions grown in a greenhouse. Sodium (Na+), potassium (K+), calcium (Ca2+), chloride (Cl?), and nitrate (NO3 ?) concentrations in the top leaves of tillers were determined at plant maturity. Regardless of genotypes, the moderate salinity significantly increased the Na+ and Cl? concentrations in the top leaves and the decreased NO3 ? in the mainstem, subtillers and whole plant. Potassium and Ca2+ concentrations in leaves were not affected or slightly increased by salinity. Under moderate salinity, Na+ and/or Ca2+ concentrations in mainstem, subtillers and the whole plant were increased with a decrease in tiller removal for both genotypes, while there was almost no effect of tiller removal on Cl? and NO3 ? concentration. The tiller removal increased the tolerance of wheat to tissue Na+ content, especially for the salt sensitive genotype. Thus, the salt-specific effects in wheat plant could be alleviated by fewer tillers per plant through the removal for the salt-sensitive genotype. However, our study did not show the competition for the mineral nutrients among tillers under saline conditions. Thus, we speculate that there is a competition for photoassimilates among the tillers under saline conditions, especially for the salt sensitive genotype, which needs to be investigated further.  相似文献   

18.
Uptake of NO3 ‐, NH4 +, P, K++, Ca++ and Mg++, as influenced by the stage of plant development and three NO3 ‐: NH4 + ratios (1: 0, 1: 1, and 0: 1), was determined for sweet pepper (Capsicum annuum L. cv. ‘California Wonder'). Uptake was highest during fruit development and immediately after fruit harvest, indicating that fruit removal promotes nutrient uptake. When NO3 ‐ and NH4 + were supplied in equal concentrations, NO3 ‐ was absorbed more readily. Each increment in NH4 + decreased the uptake of K+, Ca++, and Mg++ by fruit tissue, while no significant effect on the N and P content of the fruit was observed. Ammonium nutrition reduced plant dry weight and fruit yield in comparison to NO3 ‐. Results from this study suggest that NO3 ‐ is the preferred N form, and that fertilizer application should be scheduled according to specific physiological stages to maximize nutrient uptake. Nutrient content of vegetative tissue was not indicative of potential yield.  相似文献   

19.
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   

20.
Although there are a variety of ions occurring in the soil throughout most of North America, the majority of halophyte literature focuses on the effects of NaCl on plants. In this study, a comparison is made of the effects of NaCl, KC1, Na2SO4, and K2SO4, on growth of the halophyte Atriplex prostrata Boucher ex DC (SYN: A. triangularis Willd.) at 0, ‐0.75, ‐1.00, and ‐1.50 MPa. Plant survival, height, number of leaves, nodes, and branches were recorded weekly. Photosynthesis was measured once before plants were harvested and dry mass was determined after one month. Content of Na+, K+,‐Mg2+, and Cl‐ in plant tissue was also measured. A general trend observed was that all plant growth parameters decreased with a lowering of the medium osmotic potential, and that K+ salts were more inhibitory than Na+ salts. Ion content of plant tissue generally increased with a lowering of osmotic potential. Our data indicated that K+, a plant macronutrient, was more inhibitory to plant growth than Na+. It is possible that halophytes such as Atriplex prostrata could use Na+ as an osmoticum to adjust the vacuolar water potential, but were unable to use K+ for this function because of a specific ion toxicity. The inhibitory effect of salt on plant growth parameters and survival follow the pattern; K2SO4 >KCl>Na2SO4=NaCl.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号