Genetic analysis of NaCl tolerance in tomato

We attempted to find the suitable parents for the development of tomato hybrids for high salt soils by exploiting combining ability, gene action and heterosis. Six salt-tolerant and three salt-intolerant genotypes, along with their 18 F1 crosses, were evaluated at seedling stage under 10 and 15 dS/m (NaCl) salinity stress, compared to the control level of salinity. The experiment was laid out based on a two-way complete randomized design factorial arrangement with two replications; data on root and shoot length, fresh and dry weights, leaf area, plant length, Na(+), K(+) and K(+)/Na(+) concentrations were recorded. There was significant variation within genotypes, lines, testers, crosses, and line × tester interaction for all plant characters studied under normal and two salinity levels. Estimates of combining ability indicated that under low (10 dS/m) and high (15 dS/m) salinities, line BL1176 and tester LO2875 showed significant GCA effects for most of the traits studied. The cross-combinations 6233 × LO2875, CLN2498A x LO2875 and BL1176 × 17902 showed highest SCA values for most of the characters under 10 and 15 dS/m, respectively. Potence ratio showed that under low and high salinities, all the traits showed over dominant type of gene action except leaf area and K(+) concentration (in 10 dS/m) and shoot length, and leaf area (in 15 dS/m). The highest heterosis for most of the parameters was observed in cross-combinations BL1176 × LO2875 and CLN2498A x LO2875.     

转HAL1基因番茄的耐盐性

利用农杆菌介导的叶盘法,把HAL1 基因转入番茄,Southern杂交检测得到转基因植株.耐盐实验表明, T1代转基因番茄在150 mmol/L的NaCl胁迫下仍有43%的发芽率,200 mmol/L的NaCl胁迫下发芽率为6%,而对照种子在100和150 mmol/L的NaCl胁迫下发芽率分别为11.0%和0.转基因番茄的电解质相对外渗率小于对照,而根冠比和叶绿素含量大于对照,转HAL1基因显著提高了番茄的耐盐性.盐胁迫下Na 、K 的累积状况表明,转基因番茄根、茎、叶的K /Na 均有所提高,根系的SK/Na增大,茎、叶的RSK/Na和RLK/Na减小,说明根系对K /Na 离子的选择吸收和运输能力加强.不但选择吸收K /Na ,而且表现出整株水平上的有利于耐盐的K /Na 区域化分配.     

Unraveling salinity stress responses in ancestral and neglected wheat species at early growth stage: A baseline for utilization in future wheat improvement programs

In this study, we analyzed the behavior of several neglected, ancestral, and domesticated wheat genotypes, including Ae. triuncialis, Ae. neglecta, Ae. caudata, Ae. umbellulata, Ae. tauschii, Ae. speltoides, T. boeoticum, T. urartu, T. durum, and T. aestivum under control and salinity stress to assess the mechanisms involved in salinity tolerance. Physiological and biochemical traits including root/shoot biomasses, root/shoot ion concentrations, activity of antioxidant enzymes APX, SOD, and GXP, and the relative expression of TaHKT1;5, TaSOS1, APX, GXP, and MnSOD genes were measured. Analysis of variance (ANOVA) revealed significant effects of the salinity treatments and genotypes for all evaluated traits. Salinity stress (350 mM NaCl) significantly decreased root/shoot biomasses, K+ concentration in root/shoot, and root/shoot K+/Na+ ratios. In contrast, salinity stress significantly increased Na+ concentration in root and shoot, activity of antioxidant enzymes (APX, SOD, and GPX) and relative expression of salt tolerance-related genes (TaHKT1;5, TaSOS1, APX, GPX, and MnSOD). Based on heat map and principal component analysis, the relationships among physiological traits and relative expression of salt-responsive genes were investigated. Remarkably, we observed a significant association between the relative expression of TaHKT1;5 with root K+ concentration and K+/Na+ ratio and with TaSOS1. Taken together, our study revealed that two neglected (Ae. triuncialis) and ancestral (Ae. tauschii) wheat genotypes responded better to salinity stress than other genotypes. Further molecular tasks are therefore essential to specify the pathways linked with salinity tolerance in these genotypes.     

Response of tomato cultivars to salinity

The responses of five tomato cultivars (L. esculentum Mill) of different degrees of salt tolerance were examined over a range of 0 to 140 mM NaCl applied for 3 and 10 weeks. Judged by both Na and Cl accumulations and maintenance of K, Ca and Mg contents with increasing salinity, the most tolerant cultivars (Pera and GC-72) showed different responses. The greater salt tolerance of cv Pera was associated with a higher Cl and Na accumulation and a lower K content in the shoot than those found in the other cultivars, typical of a halophytic response to salinity. However, the greater salt tolerance of cv GC-72 was associated with a retention of Na and Cl in the root, restriction of their translocation to the shoot and maintenance of potassium selectivity under saline conditions. The salt tolerance mechanisms that operated in the remaining cultivars were similar to that of cv GC-72, as at first they excluded Na and Cl from the shoots, accumulating them in the roots; with longer treatment, the ability to regulate Na and Cl concentrations in the plant was lost only in the most salt sensitive cultivar (Volgogradskij), resulting in a massive influx of both ions into the shoot.The salt sensitivity of some tomato cultivars to salinity could be due to both the toxic effect of Na and Cl ions and nutritional imbalance induced by salinity, as plant growth was inversely correlated with Na and Cl contents and directly correlated with K and Ca contents. This study displays that there is not a single salt tolerance mechanism, since different physiological responses among tomato cultivars have been found.     

The cyclic nucleotide-gated channel, AtCNGC10, influences salt tolerance in Arabidopsis

Cyclic nucleotide-gated channels (CNGCs) in the plasma membrane transport K+ and other cations; however, their roles in the response and adaptation of plants to environmental salinity are unclear. Growth, cation contents, salt tolerance and K+ fluxes were assessed in wild-type and two AtCNGC10 antisense lines (A2 and A3) of Arabidopsis thaliana (L.) Heynh. Compared with the wild-type, mature plants of both antisense lines had altered K+ and Na+ concentrations in shoots and were more sensitive to salt stress, as assessed by biomass and Chl fluorescence. The shoots of A2 and A3 plants contained higher Na+ concentrations and significantly higher Na+/K+ ratios compared with wild-type, whereas roots contained higher K+ concentrations and lower Na+/K+ ratios. Four-day-old seedlings of both antisense lines exposed to salt stress had smaller Na+/K+ ratios and longer roots than the wild-type. Under sudden salt treatment, the Na+ efflux was higher and the K+ efflux was smaller in the antisense lines, indicating that AtCNGC10 might function as a channel providing Na+ influx and K+ efflux at the root/soil interface. We conclude that the AtCNGC10 channel is involved in Na+ and K+ transport during cation uptake in roots and in long-distance transport, such as phloem loading and/or xylem retrieval. Mature A2 and A3 plants became more salt sensitive than wild-type plants because of impaired photosynthesis induced by a higher Na+ concentration in the leaves.     

能源植物杂交狼尾草对NaCl胁迫的响应及其耐盐阈值

以能源植物杂交狼尾草(Pennisetum americanum × P. purpureum)为实验材料, 用沙培盆栽的方法, 分别用0、0.3%、0.5%、0.9%和1.2%的NaCl处理4周后, 测定植株鲜重、干重、含水量、株高、分蘖数和不同部位的离子含量, 以确定其耐盐阈值和耐盐方式。结果表明, 随着NaCl浓度的增加, 杂交狼尾草的鲜重、干重、株高和分蘖数都显著降低, 地上部分鲜重和干重分别在NaCl浓度为0.568%和0.570%时下降了50%, 1.2% NaCl处理的杂交狼尾草几乎全部死掉。表明杂交狼尾草的耐盐阈值为0.57%; 但植株含水量和功能叶的Na⁺含量变化不明显, 老叶Na⁺含量在NaCl浓度为0.9%时明显升高, 是对照的2倍; 随NaCl浓度的升高, 根中的Na⁺含量显著升高, 在NaCl浓度为0.9%时, 根中的Na⁺含量达到对照的3倍以上。Na⁺含量在功能叶, 老叶和根中含量依次升高; 随NaCl浓度的升高, 地上部分和根中的K⁺含量都无明显变化; 随NaCl浓度的升高, 根中的Na⁺/K⁺明显增加, 而地上部分Na⁺/K⁺只有当NaCl浓度为0.9%时明显增加。以上结果表明杂交狼尾草具有一定的耐盐性, 其耐盐方式为拒盐, 耐盐阈值为0.57% (约100 mmol·L^-1)。     

Photosynthetic capacity is related to the cellular and subcellular partitioning of Na+, K+ and Cl- in salt-affected barley and durum wheat

The capacity of plants to tolerate high levels of salinity depends on the ability to exclude salt from the shoot, or to tolerate high concentrations of salt in the leaf (tissue tolerance). It is widely held that a major component of tissue tolerance is the capacity to compartmentalize salt into safe storage places such as vacuoles. This mechanism would avoid toxic effects of salt on photosynthesis and other key metabolic processes. To test this, the relationship between photosynthetic capacity and the cellular and subcellular distribution of Na+, K+ and Cl- was studied in salt-sensitive durum wheat (cv. Wollaroi) and salt-tolerant barley (cv. Franklin) seedlings grown in a range of salinity treatments. Photosynthetic capacity parameters (Vcmax, Jmax) of salt-stressed Wollaroi decreased at a lower leaf Na+ concentration than in Franklin. Vacuolar concentrations of Na+, K+ and Cl- in mesophyll and epidermal cells were measured using cryo-scanning electron microscopy (SEM) X-ray microanalysis. In both species, the vacuolar Na+ concentration was similar in mesophyll and epidermal cells, whereas K+ was at higher concentrations in the mesophyll, and Cl- higher in the epidermis. The calculated cytoplasmic Na+ concentration increased to higher concentrations with increasing bulk leaf Na+ concentration in Wollaroi compared to Franklin. Vacuolar K+ concentration was lower in the epidermal cells of Franklin than Wollaroi, resulting in higher cytoplasmic K+ concentrations and a higher K+ : Na+ ratio. This study indicated that the maintenance of photosynthetic capacity (and the resulting greater salt tolerance) at higher leaf Na+ levels of barley compared to durum wheat was associated with the maintenance of higher K+, lower Na+ and the resulting higher K+ : Na+ in the cytoplasm of mesophyll cells of barley.     

江苏野生大豆的耐盐性和离子在体内的分布及选择性运输

以相对发芽率和出苗率为指标比较了3个野生大豆(Glycine soja)种群的耐盐性,测定了NaCl胁迫下2个耐盐性不同的野生大豆种群(江苏野生大豆,JWS,耐盐;N23232,盐敏感)植株根、茎和叶片中Na^+、K^+和Cl^-含量的变化。结果表明,JWS的耐盐性最强,盐胁迫抑制野生大豆幼苗生长,使其干物质积累量减少,根冠比上升,对耐盐性弱的N23232抑制作用大于耐盐性强的JWS,不同器官离子含量测定结果表明,盐胁迫下野生大豆茎部Na^+含量最高,耐盐的JWS根系具有积累Na^+和Cl^-的能力,叶片Na^+、Cl含量较低,而盐敏感种群N23232根系中：Na^+、Cl^-含量低于耐盐种群JWS,叶片中Na^+、Cl^-含量则高于JWS,JWS根系对K^+、Na^+吸收的选择性(selectivity ratio,SK,Na)和N23232没有明显差异;但叶片和茎运输的SK,Na明显高于N23232,使地上部K^+／Na^+较高,因此认为野生大豆根系对Na^+、Cl^-的积累及K^+向地上部运输的选择性高是其耐盐性强的主要原因。     

Grafting raises the salt tolerance of tomato through limiting the transport of sodium and chloride to the shoot

With the aim of determining whether grafting could improve salinity tolerance of tomato (Lycopersicon esculentum Mill.), and what characteristics of the rootstock were required to increase the salt tolerance of the shoot, a commercial tomato hybrid (cv. Jaguar) was grafted onto the roots of several tomato genotypes with different potentials to exclude saline ions. The rootstock effect was assessed by growing plants at different NaCl concentrations (0, 25, 50, and 75 mM NaCl) under greenhouse conditions, and by determining the fruit yield and the leaf physiological changes induced by the rootstock after 60 d and 90 d of salt treatment. The grafting process itself did not affect the fruit yield, as non-grafted plants of cv. Jaguar and those grafted onto their own root showed the same yield over time under non-saline conditions. However, grafting raised fruit yield in Jaguar on most rootstocks, although the positive effect induced by the rootstock was lower at 25 mM NaCl than at 50 and 75 mM NaCl. At these higher levels, the plants grafted onto Radja, Pera and the hybrid VolgogradskijxPera increased their yields by approximately 80%, with respect to the Jaguar plants. The tolerance induced by the rootstock in the shoot was related to ionic rather than osmotic stress caused by salinity, as the differential fruit yield responses among graft combinations were mainly related to the different abilities of rootstocks to regulate the transport of saline ions. This was corroborated by the high negative correlation found between fruit yield and the leaf Na(+) or Cl(-) concentrations in salt-treated plants after 90 d of salt treatment. In conclusion, grafting provides an alternative way to enhance salt tolerance, determined as fruit yield, in the tomato, and evidence is reported that the rootstock is able to reduce ionic stress.     

Na and k accumulation and salt tolerance of Atriplex canescens (Chenopodiaceae) genotypes

Sixteen accessions of the xerohalophyte, Atriplex canescens (Pursh.) Nutt., differing in tendency to accumulate Na or K in leaf tissues, were compared for salt tolerance in a greenhouse study. Plants were grown along a salinity gradient from 72 to 2017 mol/m³ NaCl measured in the root zone. Growth rates (RGR) were negatively affected by salinity for all accessions. Initial leaf levels of Na (measured before exposing plants to saline solutions) were positively correlated with subsequent RGR's of accessions on the salinity gradient (r = 0.60 - 0.88, P < 0.05 across salinity levels), whereas initial leaf K levels were negatively correlated (r = -0.68 to -0.85, P < 0.01 across salinity levels). Varieties linearis (S. Wats.) Munz and grandidentatum Stutz & Sanderson had greater tendency for Na accumulation, lower tendency for K, and higher growth rates on saline solutions than var. occidentalis (Torr. & Frem.) Welsh & Stutz accessions. Within var. occidentalis accessions, RGRs were negatively correlated with initial leaf levels of K but not Na. Postexposure leaf Na and K levels were not strongly correlated with RGR's. All accessions responded to salinity by increasing their uptake of Na, which is the primary mechanism of osmotic adjustment to salinity in this species. It is suggested that differences in tendency to accumulate Na or K among A. canescens genotypes are related to their specialization for saline or xeric habitats, respectively.     

Salt tolerance-related protein STO binds to a Myb transcription factor homologue and confers salt tolerance in Arabidopsis

Regulating the intracellular Na+/K+ ratio is an essential process for salinity tolerance. The yeast mutant, can, which is deficient in calcineurin, can not grow on medium containing Na+ because it is unable to regulate the intracellular Na+/K+ ratio. Expression of the STO gene of Arabidopsis thaliana in the can mutant complements the salt-sensitive phenotype. A protein of Arabidopsis, an H-protein promoter binding factor (HPPBF-1), that binds to STO protein was isolated. HPPBF-1 cDNA has a sequence encoding a Myb DNA binding-motif and its gene expression is induced by salt stress. Furthermore, HPPBF-1 protein is localized in the nucleus. Although, the expression level of STO is not induced under salt-stress conditions, overexpression of STO in a transgenic Arabidopsis plant gave it a higher salt tolerance than was observed in the wild type. When STO transgenic plants and wild-type plants were subjected to salt stress, root growth was increased by 33-70% in the transgenic plants under salt stress. These results suggest that STO is involved in salt-stress responses in Arabidopsis.     

Improved Tolerance of <Emphasis Type="Italic">Acacia nilotica</Emphasis> to Salt Stress by Arbuscular Mycorrhiza, <Emphasis Type="Italic">Glomus fasciculatum</Emphasis> may be Partly Related to Elevated K/Na Ratios in Root and Shoot Tissues

A pot experiment was conducted to examine the effect of arbuscular mycorrhizal fungus, Glomus fasciculatum, and salinity on the growth of Acacia nilotica. Plants were grown in soil under different salinity levels (1.2, 4.0, 6.5, and 9.5 dS m⁻¹). In saline soil, mycorrhizal colonization was higher at 1.2, 4.0, and 6.5 dS m⁻¹ salinity levels in AM-inoculated plants, which decreased as salinity levels further increased (9.5 dS m⁻¹). Mycorrhizal plants maintained greater root and shoot biomass at all salinity levels compared to nonmycorrhizal plants. AM-inoculated plants had higher P, Zn, and Cu concentrations than uninoculated plants. In mycorrhizal plants, nutrient concentrations decreased with the increasing levels of salinity, but were higher than those of the nonmycorrhizal plants. Mycorrhizal plants had greater Na concentration at low salinity levels (1.2, 4.0 dS m⁻¹), which lowered as salinity levels increased (6.5, 9.5 dS m⁻¹), whereas Na concentration increased in control plants. Mycorrhizal plants accumulated a higher concentration of K at all salinity levels. Unlike Na, the uptake of K increased in shoot tissues of mycorrhizal plants with the increasing levels of salinity. Our results indicate that mycorrhizal fungus alleviates deleterious effects of saline soils on plant growth that could be primarily related to improved P nutrition. The improved K/Na ratios in root and shoot tissues of mycorrhizal plants may help in protecting disruption of K-mediated enzymatic processes under salt stress conditions.     

Overexpression of SlSOS2 (SlCIPK24) confers salt tolerance to transgenic tomato

The Ca(2+)-dependent SOS pathway has emerged as a key mechanism in the homeostasis of Na(+) and K(+) under saline conditions. We have identified and functionally characterized the gene encoding the calcineurin-interacting protein kinase of the SOS pathway in tomato, SlSOS2. On the basis of protein sequence similarity and complementation studies in yeast and Arabidopsis, it can be concluded that SlSOS2 is the functional tomato homolog of Arabidopsis AtSOS2 and that SlSOS2 operates in a tomato SOS signal transduction pathway. The biotechnological potential of SlSOS2 to provide salt tolerance was evaluated by gene overexpression in tomato (Solanum lycopersicum L. cv. MicroTom). The better salt tolerance of transgenic plants relative to non-transformed tomato was shown by their faster relative growth rate, earlier flowering and higher fruit production when grown with NaCl. The increased salinity tolerance of SlSOS2-overexpressing plants was associated with higher sodium content in stems and leaves and with the induction and up-regulation of the plasma membrane Na(+)/H(+) (SlSOS1) and endosomal-vacuolar K(+), Na(+)/H(+) (LeNHX2 and LeNHX4) antiporters, responsible for Na(+) extrusion out of the root, active loading of Na(+) into the xylem, and Na(+) and K(+) compartmentalization.     

Salt tolerance in Aster tripolium L. II. Ionic regulation

Abstract Measurements of tissue ion contents (Na, K and Cl) were carried out at frequent intervals on plants of Aster tripolium L. grown at a range of salinities for 36 d. Aster tripolium behaved as a typical halophyte showing high levels of inorganic ion accumulation even at low salinities. As salinity increased Na replaced K to a large extent in the shoot but root K was unaffected up to 500 mol m^?3 external NaCl. Shoot (Na + K) concentration on a tissue water basis was maintained constant in all treatments throughout the experiment, whereas shoot (Na + K) on a dry weight basis showed marked fluctuations in some treatments. An increase in (Na + K) per gram dry weight was, however, accompanied by a parallel increase in fresh weight: dry weight (FW : DW) ratio. Transport of (Na + K) to the shoot per unit root weight changed during the experiment in the manner expected, given the observed changes in shoot relative growth rate and FW : DW to result in a constant shoot (Na + K) concentration on a water basis. Chloride was the major balancing anion in the shoot at high salinity, but never accounted for more than 38% of the (Na + K) found in the root tissue. At all salinities (Na + K) salts accounted for the majority of the measured shoot sap osmotic potential. The interactions between salinity, growth, ion transport and osmotic adjustment are discussed.     

Cadmium tolerance and phytoremediation potential of acacia (Acacia nilotica L.) under salinity stress

In this study, we explored the effect of salinity on cadmium (Cd) tolerance and phytoremediation potential of Acacia nilotica. Two-month-old uniform plants of A. nilotica were grown in pots contaminated with various levels of Cd (0, 5, 10, and 15 mg kg^?1), NaCl (0%, 0.5%, 1.0% (hereafter referred as salinity), and all possible combinations of Cd + salinity for a period of six months. Results showed that shoot and root growth, biomass, tissue water content and chlorophyll (chl a, chl b, and total chl a+b) contents decreased more in response to salinity and combination of Cd + salinity compared to Cd alone. Shoot and root K concentrations significantly decreased with increasing soil Cd levels, whereas Na and Cl concentrations were not affected significantly. Shoot and root Cd concentrations, bioconcentration factor (BCF) and translocation factor (TF) increased with increasing soil Cd and Cd + salinity levels. At low level of salinity (0.5%), shoot and root Cd uptake enhanced, while it decreased at high level of salinity (1.0%). Due to Cd tolerance, high shoot biomass and shoot Cd uptake, this tree species has some potential for phytoremediation of Cd from the metal contaminated saline and nonsaline soils.     

Foliar applied fullerol differentially improves salt tolerance in wheat through ion compartmentalization,osmotic adjustments and regulation of enzymatic antioxidants

Earlier we reported that seed pre-treatment with PHF promoted early seedling growth and salinity tolerance in wheat. As a way forward, experiments were conducted to investigate whether and to what extent foliar spray of fullerol could influence growth and physio-biochemical responses in salt stressed wheat. In a control experiment, seeds were sown in sand filled pots (500 g) under control and 150 mM NaCl stress. After 15 days, foliar spray of fullerol at 0, 10, 40, 80 and 120 nM concentration was applied and the data for various morpho-biochemical attributes recorded after 2 weeks. Fullerol caused improvements in shoot growth attributes while had least effect on root growth traits. Increase in total chlorophyll while reduction in Car/Chl ratio was evident under salinity in response to fullerol spray. Only 40 and 80 nM spray treatments improved antioxidant activities and reduced H2O2 contents while MDA contents which increased due to salt stress, remained unaffected by foliar spray. Fullerol spray also improved sugars, proline and free amino acids under salinity. During second experiment under natural conditions, 60 day old plants grown in sand filled pots (10 kg) under 0 and 150 mM NaCl were foliar sprayed with selected concentrations (0, 40 and 80 nM) of fullerol. Salinity inhibited gas exchange and grain yield attributes while fullerol-sprayed plants exhibited recovery. Fullerol spray resulted in high root and shoot K+ and shoot Ca2+ contents. Also, increase in shoot and root P, while lesser shoot Na+ was recorded due to 80 nM spray under salt stress. Overall, 40 and 80 nM fullerol spray improved photosynthetic activity, osmolytes accumulation and altered tissue ion compartmentalization which contributed to improvement in grain yield attributes under salinity.     

Interactive effects of Ca2+ and NaCl salinity on the growth of two tomato genotypes differing in Ca2+ use efficiency

Two tomato (Lycopersicon esculentum Mill.) lines differing in Ca²⁺ use efficiency (Ca²⁺ use efficient line 113 and Ca²⁺ use inefficient line 67) were subjected to salinity treatments in two separate experiments to determine whether they differed in salt tolerance. In experiment I, three NaCl and two CaCl₂ treatments were imposed. The Na⁺ concentrations were 1.1, 100 and 150 mM and the Ca²⁺ concentrations were either 1.51 or 10 mM. In experiment II, one NaCl and three Ca²⁺ treatments (as CaCl₂ or CaSO₄) were imposed. The treatments consisted of 150 mM NaCl at either 1.51 mM CaCl₂, 10 mM CaCl₂, or 10 mM CaSO₄. Response to treatments was determined by analysis of growth parameters (shoot and root dry weights, plant height, and root length). Shoot and root dry weight, and root length were depressed as salinity increased in plants lacking additional Ca²⁺. No significant differences in salt tolerance were detected between the two tomato lines after 24 d of salinity treatment. An important finding of this study was that root growth and length appeared to be more sensitive to the effect of CaCI₂ treatment alone and to the effects of CaCl₂ × NaCl treatments. This suggests that over the long term, both root growth and root length may be more sensitive indicators of salinity effects than shoots. Supplemental CaCl₂ had no ameliorative effect on NaCl stress in shoot growth. The inability of Ca²⁺ to counter Cl⁻ entry or toxicity may account for the lack of amelioration. Additional Ca²⁺ as CaSO₄ improved shoot growth of plants exposed to 150 mM NaCl. In contrast, root growth and length were improved by 10 mM Ca²⁺ as either CaCl₂ or CaSO₄.     

NaCl胁迫对小麦幼苗生长、叶绿素含量及Na^＋、K^＋吸收的影响

对宁夏地区种植的几个春小麦品种和国内外引进的抗盐小麦材料的幼苗进行不同浓度NaCl胁迫处理,结果表明：NaCl胁迫对小麦幼苗地上部生长抑制显著,而对地下部生长影响较小;NaCl胁迫对小麦幼苗的胁迫主要是离子伤害,而渗透胁迫不明显;随NaCl浓度的增加,叶绿素含量显著下降,同时植株中Na^ 含量增加,K^ 含量下降,K^ /Na^ 降低;不同品种对不同浓度NaCl的胁迫反应不同。