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1.
The experiment containing three replicates of completely randomized factorial treatments was conducted in a glasshouse under controlled conditions with three simulated soil salinity levels (control, 10 and 15 dS m?1). Morpho-physiological traits (i.e. lengths, fresh weights and dry weights of root and shoot, number of leaves, root/shoot ratio, shoot Na+ accumulation, K+/Na+ ratio, Ca2+/Na+ ratio, membrane stability index, lycopene contents, chlorophyll-a and -b) were recorded to determine mechanism of salt tolerance of tomato at seedling stage. Principal component analysis (PCA) was used to express a three-way interaction of genotype × salinity level × traits that scattered the 25 tomato genotypes based on their morpho-physiological response to different NaCl levels. The negative association of Na+ with all other traits except root/shoot ratio and the morpho-physiological response trend of genotypes exposed that probable mechanism of salt tolerance was initially Na+ exclusion by abscising older leaves to have younger physiologically energetic, and lastly a higher activity of plants for root development to sustain them in saline soil. PCA three-way biplot efficiently recognized ANAHU, LA-2821, LO-2752, LO-2707, PB-017909, LO-2831-23 and 017860 as salt tolerant genotypes. On the other hand, ZARNITZA, GLACIER, LO-2692, LO-2576, BL-1079, 006233, 006232, 017856, NUTYT-701 and NAGINA were found to be salt susceptible.  相似文献   

2.
Identification of novel wheat (Triticum aestivum L.) germplasm is imperative to develop salt tolerant varieties. In the first phase, 400 accessions were screened against high salt stress (200 mM NaCl) on the basis of Na+ accumulation in leaf blade, and 40 genotypes with contrast reaction to salinity were selected. Salt tolerant group (25 genotypes) had higher leaf K+/Na+ ratio, maximum root and shoot lengths, leaf fresh/dry weights and chlorophyll content as compared to the salt sensitive group (15 genotypes). In second phase, physiologically based screening was performed on selected genotypes against varying salinity levels (0, 100 and 200 mM NaCl). GGE biplot analysis indicates that genotypes TURACO, V-03094, V0005, V-04178, Kharchia 65 and V-05121 were the most salt-tolerant and declared winners as depicted by more gaseous exchange relations and growth potential which was strongly correlated with proper Na+, K+ discrimination in leaf and root tissues. Genotypes PBW343*2, NING MAI 50, PGO, PFAU, V-04181, PUNJAB 85, KIRITATI, TAM200/TUI and TAM200 were poor performer due to more Na+ accumulation in leaf ultimately retarded growth. In conclusion, low Na+ accumulation in leaf can be used as the best screening criteria, employing a large set of genotypes in a breeding program.  相似文献   

3.
Soil management through the cultivation of salt-tolerant plants is a practical approach to combat soil salinization. In this study, salt tolerance of 35 barley (Hordeum vulgare L.) genotypes was tested at four salinity levels (0, 100, 200, and 300 mM NaCl in Hoagland nutrient solution) at two growth stages (germination and vegetative). The relationship between salinity tolerance and carbon isotope discrimination (CID) was also accessed. Results of the study carried out under laboratory conditions showed that a negative linear relationship was observed between salt concentration and germination as well as other growth parameters. Some genotypes showed good salt tolerance at germination but failed to survive at seedling stage. However, five genotypes, namely, Jau-83, Pk-30109, Pk-30118, 57/2D, and Akermanns Bavaria showed better tolerance to salinity (200 mM) both at germination and at vegetative growth stage. The salt tolerance of these barley genotypes was significantly correlated with minimum decrease in K+:Na+ ratio in plant tissue with increase in the root zone salinity. However, the case was reversed in sensitive genotypes. CID was decreased linearly with increase in root zone salinity. However, salt-tolerant genotypes maintained their turgor by osmotic adjustment and by minimum increase in diffusive resistance and showed minimum reduction in CID (Δ) with gradual increase in rooting medium salt concentration. Results suggested that the tolerant genotypes make osmotic adjustments by selective uptake of K+ and by maintaining a higher K+:Na+ ratio in leaves. Moreover, CID technique can also be good criteria for screening of salt-tolerant germplasm.  相似文献   

4.
A study of the salinity effect on mineral content in rice genotypes differing in salt tolerance was conducted in a factorial Completely Randomized Design experiment. The results indicated that the genotypes developed differently by mutation conventional breeding. NS15 represented as salt-sensitive, Pokkali was included as an internationally salt-tolerant check and Iratom24 was moderately tolerant. The content of Na+, Ca2+, Mg2+ and Cl? followed an increasing pattern in roots and shoots of all the rice genotypes due to increasing salinity levels except Ca2+ and Mg2+ in the root. However, the concentration of K+ showed more or less an increasing pattern in root and a decreasing pattern in shoot. The concentration of Na+ and Ca2+ sharply increased with increasing the salinity levels in both the roots and shoots of NS15. The concentration of K+ sharply decreased in shoot and increased in the root of susceptible genotype NS15 with increasing salinity over 6 dS m?1 salinity levels, where the transformation of K+ from root to shoot was disrupted by Na+. The Cl? content sharply increased with increasing salinity in the root of NS15 as compared to shoot. The effect of different salinity levels on Na+/K+ ratio in the shoots of the selected rice genotypes sharply increased in susceptible genotype NS15 as compared to the other genotypes.  相似文献   

5.
Soybean plants, varieties “Lee”, “Jackson” and “Bragg” were grown in solution culture at various salinity levels. A NaCl concentration of 10 mM was already inhibitory to growth of “Jackson”; growth of “Lee”, however, was only reduced at a salt concentration of 50 mM or higher. The moderately salt tolerant variety “Lee” efficiently excluded Cl? from the leaves up to about 50 mM NaCl in the medium, but showed high Cl? contents in the root; exclusion of Na+ from the leaves was also apparent in this variety. On the other hand, the salt sensitive variety “Jackson” did not have the capacity for exclusion of Cl? and Na+. The physiological behaviour of the variety “Bragg” resembled that of “Jackson”. It is suggested that the exclusion of Cl? and Na+ from the leaves in the soybean variety “Lee” is regulated by the root.  相似文献   

6.
Abstract

To assess whether grafting raised the salt tolerance of cucumber seedlings by limiting transport of Na+ to the leaf and to test whether the salt tolerance of grafted plants was affected by the shoot genotype, two cucumber cultivars (“Jinchun No. 2”, a relatively salt-sensitive cultivar, and “Zaoduojia”, a relative salt-tolerant cultivar) were grafted onto rootstock pumpkin (Cucurbita moschata Duch. cv. “Chaojiquanwang”, a salt-tolerant cultivar). Ungrafted plants were used as controls. The effects of grafting on plant growth and ion concentrations were investigated under NaCl stress. Reductions in the shoot and root dry weights, leaf area and stem diameter of grafted plants were lower and concentrations of K+ and Cl? in the leaves were higher than those of ungrafted plants under the same NaCl stress. The Na+ concentration and Na+/K+ ratio in scion leaves and in the stems of grafted plants were lower, whereas those in rootstock stems and roots were higher than in ungrafted plants under the same NaCl stress. Shoot and root dry weight, leaf area and stem diameter were negatively correlated with leaf Na+ concentrations and Na+/K+ ratio, but were positively correlated with leaf K+ concentrations. The Na+ concentrations and Na+/K+ ratio were lower, whereas the K+ concentrations in the leaves of grafted “Zaoduojia” plants were higher than those in grafted “Jinchun No. 2” plants under the same NaCl stress. The reductions in leaf area and stem diameter of grafted “Jinchun No. 2” plants were more severe than those of grafted “Zaoduojia” plants. These results indicate that: (1) the higher salt tolerance of grafted cucumber seedlings is associated with lower Na+ concentrations and Na+/K+ ratio and higher K+ concentrations in the leaves, (2) grafting improved the salt tolerance of cucumber seedlings by limiting the transport of Na+ to the leaves, (3) the salt tolerance of grafted cucumber seedlings is related to the shoot genotype.  相似文献   

7.
In the course of investigations on the impact of salinity on mineral ion transport in differentially salt susceptible soybeans (“Lee” and “Jackson”) short-term experiments were conducted to elucidate the distribution pattern of Na+ and some other cations. The results showed that low salinity (7.5 mM NaCl) did not induce varietal differences in Na+ content during a 30 hrs uptake period. At 66.5 mM NaCl, however, the Na+ contents increased more in the leaves of the salt sensitive variety “Jackson” than in “Lee”. Both soybean varieties retained Na+ in the proximal root and stem. Furthermore, they extruded considerable amounts of Na+ from the roots to the medium. Increasing the level of salinity in the solution substantially reduced the Ca2+ uptake of both soybean varieties. In an experiment with the salt sensitive variety under constant salinity but increasing Ca2+ concentration in the medium, the plants showed a reduction in Na+ uptake and translocation to stem and leaves and an enhanced Ca2+ uptake and translocation to the shoots. It is suggested that the injury observed in “Jackson” after salt treatment is not only related to the insufficient control of Cl? transport. At higher salinity levels the increasing accumulation of Na+ in the leaves and the varietally independant depression of Ca2+ uptake and translocation may enhance the development of leaf necrosis.  相似文献   

8.
This experiment was conducted in a glasshouse at the Agricultural and Natural Resources Research Center of Zarghan, Iran, in 2016. Sixteen wheat genotypes were compared under four salinity levels [control, 50, 100, and 150 mM sodium chloride (NaCl)] in terms of grain yield, chlorophyll (SPAD), flag leaf area, Na+/K+ ratio, catalase, and peroxidase activities in a randomized complete block design with three replications. Overall, results indicated that apparently no single parameter or a specific group of parameters could be suggested as factors of the most responsive element to different salinity stress levels. In other words, the tolerance mechanism of wheat genotypes is a complex response of multiple factors as a network path. Furthermore, different salinity levels led to different responses of wheat genotypes, which were detectable by the results of the mean comparison and analysis of variance. These results also proved the influential effects of the genetic background on salinity response and tolerance of wheat genotypes. In addition, antioxidants acting as defense barriers against reactive oxygen species are very important constituents against salinity, since higher antioxidant activity leads to alleviate the oxidative stress caused by salinity. Higher osmolyte concentration regulating the selective uptake of useful ions can prevent excess accumulation of toxic ions, which contribute to salinity stress damages. A high variation related to the measured traits in this study under both normal and salinity stress conditions was achieved, which could be applied in screening and breeding programs for salinity stress tolerance. Moreover, the responses of different genotypes varied regarding the different traits; SU-0129 as a novel genotype has proved to be the best choice for further breeding research based on the overall traits and, in particular, grain yield and tolerance stress index.  相似文献   

9.
Silicon (Si) is known to alleviate a number of abiotic stresses in higher plants including salinity stress. Two independent experiments were conducted to evaluate the role of Si in alleviating salinity stress in two contrasting wheat (Triticum aestivum L.) genotypes, Auqab-2000' (salt sensitive) and SARC-3 (salt tolerant). In the first experiment, genotypes were grown in hydroponics with two levels of salinity (0 and 60 mM NaCl) with and without 2 mM Si in a completely randomized design with four replications. Salinity stress significantly (P < 0.01) decreased all of the growth parameters, increased sodium (Na+) concentration, and decreased potassium (K+) concentration in shoots of both genotypes grown in hydroponics. Silicon significantly improved growth of both genotypes. The increase in growth was more prominent under salt stress (75%) than under normal condition (15%). In the second experiment, both genotypes were grown in normal [electrical conductivity (EC) = 1.23 d Sm–1] and natural saline field (EC = 11.92 d Sm–1) conditions with three levels of Si (0, 75, and 150 g g–1 Si) with three replications in a randomized complete block design. Silicon significantly (P < 0.05) decreased growth reduction in both genotypes caused by salinity stress. The grain yield under salt stress decreased from 62% to 33% and from 44% to 20% of the maximum potential in Auqab-2000 and SARC-3, respectively, when 150 g g–1 Si was used. Auqab-2000 performed better in normal field conditions, but SARC-3 produced more straw and grain yield in saline field conditions. Addition of Si significantly (P < 0.05) improved K uptake and reduced Na+ uptake in both of wheat genotypes and increased the K+/Na+ ratio in shoot. Enhanced salinity tolerance and improved growth in wheat by Si application was attributed to decreased Na+ uptake, its restricted translocation toward shoots, and enhanced K+ uptake.  相似文献   

10.
Soil salinity is a concern in the wake of climate change challenges due to rising sea levels and coastal salinity in Papua New Guinea. A greenhouse experiment was conducted in Split Plot design, with five elite sweet potato genotypes (main-plot factors) and three levels of sodium chlroide (NaCl) concentrations (sub-plot factors) replicated six times. The vine cuttings of genotype RAB 45 showed very low mortality percentage (33%) at 600 mM NaCl concentration. At salinity level of 200 mM NaCl, aerial dry biomass of the genotypes was inversely but significantly (r = –0.40; p < 0.05) related to the accumulation of sodium (Na+) in the tissues. The Na+ accumulation in the tissues was antagonistic to the potassium (K+) and calcium (Ca2+) ions. Among the sweetpotato genotypes, Na+/K+ ratio decreased in the following order: RAB 45> KAV 11 > Northern Star > DOY 2 > L 46, which was more or less corroborated with the trend in the aerial dry matter.  相似文献   

11.
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12.
Short-term tracer experiments (36Cl) were conducted with the differentially salt susceptible soybean cultivars “Lee” (moderately tolerant) and “Jackson” (sensitive) to elucidate the pattern of Cl? uptake and translocation in relation to the physiology of salt tolerance. Rates of Cl? uptake by excised roots of “Jackson” were much greater in the lower (0.1–0.5 mM NaCl) and particularly in the higher concentration range than by the more tolerant cultivar. The transfer rate to the shoot was significantly higher in “Jackson” than in “Lee” and increased with time of treatment. The cultivar “Lee” translocated a relatively high amount of Cl? during the onset of salt treatment, but in contrast to “Jackson” was then able to slow down Cl? translocation into the shoot to a degree about proportional to the increment of dry matter. In experiments on secondary translocation both cultivars extruded substantial amounts of 36Cl? to the nutrient solution during the period in inactive solution with constant salinity following labeling. Possibly, some Cl? that had moved into the leaves during labeling was retranslocated and extruded via the roots. The absolute efflux rate was presumably greater for “Jackson” than for “Lee” although it appeared not efficient enough to compensate for the high rate of influx into the root. After 5–6 days of secondary translocation a lesser amount of Cl? was shifted from the root to the shoot in “Lee” as compared with “Jackson”. Chloride accumulation in the upper root and lower stem, similar to that reported for Na+ in several Na+ excluding species, was not observed. From the results it may be concluded that the cultivar “Jackson” cannot sufficiently control the uptake of Cl? and its translocation, particularly into the mature leaves; this contributes causally to the development of severe injury under continuous salt stress.  相似文献   

13.
The aim of this study was to investigate the impact of application of calcium silicate and salinity singly, on plant growth and nutritional behavior and photosynthetic pigments of tomato. Application of sodium chloride (NaCl) induced significant reduction in plant development and growth parameters. Salt stress also led to an accumulation of sodium (Na+) and a decrease in potassium (K+) concentration. Reduction of chlorophyll and carotenoid in leaves were amongst other symptoms in salt-affected plants in 2 cultivars. Rio Grande was qualified as salt sensitive and Moneymaker as the salt tolerant genotype. Application of Silicon (Si) only improved plant behaviour as compared to control. Furthermore, Si induced ameliorative effects on the growth potential of NaCl stressed plants. This Si-ameliorative effect on plant varied depending on the considered cultivar and Si concentration. Based on these results, application of calcium silicate was suggested as an alternative way to ameliorate the harmful effects of salinity on tomato.  相似文献   

14.
Effect of water salinity was studied in different Matricaria recutita L. genotypes (Isfahan, Ahvaz, and Shiraz) to understand their protective mechanisms and agronomic performance. Based on a split-plot design arranged in a randomized complete-block consisted of four salinity levels as the main plot and three genotypes as the subplots with three replications this field experiment was conducted in 36 plots with 3 m2 space in the Isfahan Center for Research of Agricultural Science and Natural Resources during 2014–2015. The findings showed that the three genotypes differed in resistance to salinity and tolerance mechanisms. They have evolved different physiological, morphological, and biochemical adaptations to salt stress. The Ahvaz genotype in the absence of salt, the Isfahan genotype at 6, and the Shiraz genotype at 9 and 12 dS m?1 sodium chloride (NaCl) were desirable, taking both quantity and quality into consideration. While preserving shoot growth, the Isfahan genotype was more tolerant to 6 dS m?1 NaCl most likely due to peroxidase activity. The resistance of the Shiraz genotype is associated with root growth stimulation at 9 and Na compartmentation in root at 12 dS m?1 NaCl. The Isfahan genotype had the highest oil and chamazulene content, which was not affected by salinity. The Shiraz genotype in the control treatment, the Isfahan genotype at 6 and 9 and the Ahavaz genotype at 12 dS m?1 NaCl synthesized higher flavonoid compounds.  相似文献   

15.
Based on the literature, under-utilized hulled wheats could be tolerant to some harsh environmental conditions. The effect of salt stress on chlorophyll content, leaf area, dry weight, and ion concentrations in eight genotypes of tetraploid wheat (Triticum turgidum) using a three-replicate completely random design indoor experiment was studied. These genotypes included six hulled wheat (HW), T. turgidum subspp. Dicoccum, and two free-threshing wheat (FTW), T. turgidum subspp. durum. Salt stress was induced by adding sodium chloride (NaCl) to a hydroponic medium to 40, 80, and 120 mM, in addition to control. Salinity reduced leaf content of chlorophyll a (chl-a) at 120 mM but had not significant effect on chlorophyll b (chl-b) content. Salt stress decreased plant leaf area by nearly 63%. Plant top dry weight declined by 52% with increasing salinity to 120 mM level. Plant top calcium (Ca2+) content was not affected, whereas plant top sodium (Na+) concentration increased and potassium (K+) and magnesium (Mg+) concentration decreased with increasing salinity, averaged over genotypes. No significant interaction of genotype × salinity was detected for traits studied in this experiment. When contrasted as two groups of genotypes, i.e., HW vs. FTW, the former group suffered more severe decreases in terms of chl-a, chl-b, leaf area, dry weight, and Mg2+ concentration and a more pronounced increase in Na+ compared to the FTW. Overall, no evidence of salt tolerance was found for hulled tetraploid wheats of central Iran.  相似文献   

16.
We studied the growth and ionic composition of five wheat genotypes (Inqlab-91, Uqab 2002, SARC-1, SARC-3, and SARC-5) grown under salinity stress to applied silicon. Plants were grown with three levels of salinity [0, 60, and 120 mM sodium chloride (NaCl)] in the presence of 0, 2, and 4 mM Si in nutrient solution for 40 days. Salinity stress significantly decreased shoot and root biomass in plants with varying degrees. Genotype SARC-3 exhibited higher salt tolerance than other genotypes. Silicon (Si) application significantly (P < 0.05) increased plant biomass at both control as well as under saline conditions. Genotypes differed significantly for their response to applied Si in terms of biomass production. Silicon application significantly (P < 0.01) increased potassium (K+) concentration in shoots. Enhanced salinity tolerance in wheat by Si application was attributed to increased K+ uptake thereby increasing K+/sodium (Na+) ratio and lower Na+ translocation towards shoot.  相似文献   

17.
Thirty eight accessions of brown mustard (Brassica juncea (L.) Czern. and Coss.) were screened after two weeks growth in solution culture containing 120 mol m‐3 NaCl. Considerable variation for salt tolerance was observed in this set of germplasm, since some accessions showed relatively vigorous growth in saline medium.

In order to determine the consistency of degree of salt tolerance at different growth stages of crop life cycle two salt tolerant accessions, P‐15 and KS‐51 and two salt sensitive 85362 and 85605 were tested at the adult stage in 0(control), 100 and 200 mol m‐3 NaCl. Both the tolerant accessions produced significantly greater fresh and dry biomass and had considerably higher seed yield than those of the salt sensitive accessions. Analysis of different ions in the leaves showed that salt tolerant accessions contained greater amounts of Na+, K+ and Ca2+ than the salt sensitive accessions, although they did not differ significantly for leaf Cl‐. Only one salt tolerant accession P‐15 had greater leaf K/Na ratio and K+ versus Na+ selectivity compared with the tolerant KS‐51 and the two salt sensitive accessions.

From this study it was established that there is a considerable variation for salt tolerance in B.juncea which can be exploited by selection and breeding for improvement of its salt tolerance. Since the degree of salt tolerance in B.juncea does not change at different growth stages of the crop life cycle, selection for salt tolerance at the initial growth stages could provide individuals that would be tolerant at all other growth stages. Accumulation of Na+, K+ and Ca2+ in the leaves are important components of salt tolerance in B.juncea.  相似文献   

18.
Salinity adversely affects plant growth, photosynthesis, and availability of nutrients including iron. Rice (Oryza sativa L.) is susceptible to soil salinity and highly prone to iron (Fe) deficiency due to lower release of Fe‐chelating compounds under saline conditions. In order to investigate the effects of salinity and low iron supply on growth, photosynthesis, and ionic composition of five rice genotypes (KS‐282, Basmati Pak, Shaheen Basmati, KSK‐434 and 99417), a solution culture experiment was conducted with four treatments (control, 50 mM NaCl, Fe‐deficient, and 50 mM NaCl + Fe‐deficient). Salinity and Fe deficiency reduced shoot and root growth, photosynthetic and transpiration rates, chlorophyll concentration, and stomatal conductance. The reduction in all these parameters was more in the interactive treatment of salinity and low Fe supply. Moreover, a significant increase in shoot and root Na+ with corresponding decrease in K+ and Fe concentrations was also observed in the combined salinity and Fe‐deficiency treatment. Among the tested genotypes, Basmati Pak was the most sensitive genotype both under salt stress and Fe deficiency. The genotype KS‐282 performed better than other genotypes under salinity stress alone, whereas Shaheen Basmati was the best genotype under Fe deficiency in terms of all the studied parameters.  相似文献   

19.
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   

20.
The salinity tolerance of nine grape genotypes was studied. Salinity was applied as nutrient solutions containing 0, 25, 50, and 100 mM sodium chloride (NaCl) for two weeks. Growth was significantly reduced by salinity, whereas chloride (Cl?) and sodium (Na+) contents increased. Sodium ion accumulation exceeded that of Cl? in all treatments. Shirazi and H6 had higher and lower Cl? concentrations in their lamina than others. There were significant positive correlations (P < 0.01) between Cl? and Na+ and negative correlation between Na+ and potassium (K+) in roots and laminas of all genotypes. Soluble sugars, proline, and glycine betaine contents increased in laminas of all of the genotypes with moderate salinity. There were positive correlations (P < 0.01) between lamina and root Na+ and Cl? contents and compatible solutes in all genotypes. Overall results revealed that unlike Shirazi with higher Na+ and Cl? accumulation in shoot, H6 showed a higher capacity to restrict Na+ and Cl? transport to shoot.  相似文献   

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