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1.
Salt stress effects were investigated on growth, the carbohydrate levels and the activity of degradative enzymes amylases, phosphorylase and invertase of two soybean varieties, Jackson and the more salt tolerant Lee.

Stress depressed growth of Jackson more than of Lee. Salt stress increased leaf and root sucrose more in Jackson than it did in Lee. Root sucrose was higher in Lee. Stress reduced leaf starch in both. It decreased spec. invertase activity in close negative correlation with the sucrose. Independent from salt tolerance, increased spec. amylase activity was in some correlation with the declined starch level. Stress changed phosphorylase little in both varieties. It is concluded that salt stress‐induced restricted utilization of leaf sucrose, but not foliar starch, could partly be a result of ionic affected degradation, which may diminish survival value of soybean varieties.  相似文献   


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

3.
The effects of salinity on carbohydrates in leaves and roots of different salt tolerant cotton genotypes Glza 45 (salt tolerant) and Dandara (salt sensitive) during the initial salinity stress are investigated. Changes of starch and sucrose in relation to soluble amylases, phosphorylase and invertase in young leaves are studied. The plants are grown in water culture under controlled conditions.

Starch and sucrose accumulation is rapidly stimulated in leaves of Dandara, particularly due to extreme potassium sulfate supply, while in Giza 45 the amount of starch and sucrose declines except for extreme potassium sulfate treatment. The low sucrose value in roots of Dandara increases extremely, especially as a result of potassium chloride treatment. In contrast, the higher sucrose content in roots of Giza 45 is little affected. Amylase activity changes considerably in positive correlation with the starch content, whereas the low specific activity of phosphorylase is little affected. The sucrose content in the leaves is directly controlled by a high level of invertase activity of both cotton varieties.

Possible interactions of carbohydrate metabolism and genotyplcal ion regulation in response to the different salt tolerance of the genotypes are discussed. It is concluded that genotypical differences in the carbohydrate metabolism could be effective mechanisms for salt tolerance in cotton.  相似文献   


4.
Osmotic and specific ion effects are the most frequently mentioned mechanisms by which saline substance reduces plant growth. However, the relative importance of osmotic and specific ion effect on plant growth seems to vary depending on the salt tolerance of the plant under study. Tall wheatgrass (TW), perennial ryegrass (PR), African millet (AM) and Rhodesgrass (Rh) were grown in nutrient solution with sodium chloride (NaCl), sodium sulfate (Na2SO4), potassium chloride (KCl), and potassium sulfate (K2SO4) salinity up to electrical conductivity (EC) 27 dS m?1. Growth of all plant species decreased significantly at high level (EC 27 dS m?1) of NaCl and Na2SO4 salts. However, the growth of none of the plant species was affected significantly by KCl and K2SO4 at any level. Even leaf and shoot fresh weights were enhanced by K2SO4 in all plant species, except AM. Chlorine (Cl) was taken up in similar quantities from KCl and NaCl solutions and the content of the respective cations was similar to each other. Further sensitivity to sulfate and chloride was equal when sodium concentrations in shoots were equal, regardless of the anion composition of the media. The sodium (Na) concentration of the leaves of the plant species increased with increased NaCl and Na2SO4 levels in the nutrient solutions. The leaf Na concentration of TW was lower than that of the other plant species. However, the root Na concentration of TW was higher than that of the other plant species. Increased NaCl and Na2SO4 concentrations had a marked effect on leaf water potential of all plant species, and the TW showed higher leaf water potential at all levels of salts. Tall wheatgrass adjusted osmotically by accumulating electrolytes from the nutrient solution and by accumulation of glycinebetaine. Sodium was generally found more injurious than Chloride in all the four forage species. Salt tolerance could be ascribed as greater exclusion of Na ion.  相似文献   

5.
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   

6.
ABSTRACT

The effects of saline water containing 0, 50, 100, and 150 mM sodium chloride (NaCl), and 100 mM NaCl + 100 mM potassium (K) on photosynthesis, water relations, and ion and carbohydrate content of olive (Olea europaea L.) cultivars ‘Koroneiki’ and ‘Mastoidis’ were studied on five-year-old trees. Salinity increased sodium (Na+) and chloride (Cl?) in tissues of both cultivars, but more so in ‘Koroneiki’ than in ‘Mastoidis.’ Salt-toxicity symptoms were observed at 100 and 150 mM, but not in plants receiving extra K. In salt-stressed plants, leaf water potential declined, whereas turgor potential remained positive due to a rapid decrease in osmotic potential. Salinity increased mannitol content up to 41.3% in ‘Mastoidis’ and 15.8% in ‘Koroneiki’, but reduced starch content in leaves. Photosynthetic rates fell significantly with increasing salinity in both cultivars, but more so in ‘Koroneiki’ than in ‘Mastoidis’. Potassium supplements reduced the concentration of Na+ and increased the concentrations of K+ in leaves, but decreased photosynthesis.  相似文献   

7.
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   

8.
The effect of sodium chloride (NaCl), sodium sulfate (Na2SO4), and potassium chloride (KCl) on growth and ion concentrations of faba bean (Vicia faba L. cv. Troy) was studied. After 14 or 15 d of isoosmotic treatment with 100 mM NaCl or 75 mM Na2SO4, respectively, plants developed toxicity symptoms. These symptoms were characterized by local and nonchlorotic wilting spots, which later turned to black, necrotic spots. In contrast to NaCl or Na2SO4 treatment, plants treated with 100 mM KCl did not show these symptoms. The symptoms occurred on those leaves that accumulated highest concentrations of Na+ and showed highest Na+ : K+ ratios. Our results indicate that Na+ toxicity inducing K+ deficiency is responsible for the spot necrosis of faba bean. Additionally, chlorotic symptoms occurred. The concentrations of Na+ and Cl were determined in chlorotic leaves and in isolated chloroplasts. The reduction of chlorophyll in leaves after NaCl exposure may be explained in terms of high Cl concentrations in the chloroplasts and appears to depend on high Na+ concentrations. Chlorotic toxicity symptoms can be avoided by additional Mg2+ application.  相似文献   

9.
Effect of NaCl and Na2SO4 on dry matter production, mineral content and organic compounds of spinach and lettuce . In water culture experiments the effect of 2,5 meq and 25 meq NaCl and Na2SO4 respectively on dry matter production and content of mineral elements, chloroplasts pigments and carbohydrates in lettuce (salt sensitive) and spinach (salt tolerant) has been studied. With increasing Na-supply the dry matter production was decreased in lettuce and increased in spinach. With increasing Na-supply in both species the content of K, Mg and Ca in the leaves decreased. This decrease was more pronounced with sulfate as accompanying anion (Na2SO4) and induced already deficiency in Ca and Mg. This induced deficiency of Mg was reflected especially in lettuce in lower contents of chloroplasts pigments. In both plant species there was no effect of the Na salt treatments on the content of phosphorus or nitrogen in roots or leaves. The carbohydrate content in both species was strongly affected by the Na salt treatments. Irrespectively of the accompanying anion this effect occured already at the low Na supply and before the dry matter production was influenced. In leaves and roots of lettuce the contents of glucose, fructose and sucrose was considerably decreased; this decrease was less expressed in the starch content. In spinach the Na supply only decreased the carbohydrate content in the roots whereas in the leaves especially the sucrose content was increased. This different effect of Na on carbohydrate content in spinach and lettuce could be an indication of different action of Na on carbohydrate metabolism, namely inhibited synthesis in lettuce and inhibited translocation in spinach. The results demonstrate that in studies on the effect of increasing Na salt concentrations besides the osmotic effects also the ion specific effects have to be carfully considered. These ion specific effects are competition of Na+ with other cations during uptake and the influence of Na on the cell metabolism, especially on the pathway of carbohydrates. The authors thanks Mrs. Hwie Juen Tjandraatmadja for her engaged help in various laboratory works.  相似文献   

10.
Background and aims : Most physiological and biochemical studies on salt stress are NaCl‐based. However, other ions (e.g., K+, Ca2+, Mg2+, and SO 4 2 - ) also contribute to salt stress in special circumstances. In this study, salt stress induced by various salts was investigated for a better understanding of salinity. Methods : Arabidopsis thaliana plants were stepwise acclimated to five iso‐osmotic salts as follows: NaCl, KCl, Na2SO4, K2SO4, and CaCl2. Results and Conclusions : Exposure to KCl and K2SO4 led to more severe toxicity symptoms, smaller biomass, and lower level of chlorophyll than exposure to NaCl and Na2SO4, indicating that Arabidopsis plants are more sensitive to potassium salts. The strongly reduced growth was negatively correlated with the accumulation of soluble sugars observed in KCl‐ and K2SO4‐treated plants, suggesting a blockage in the utilization of sugars for growth. We found that exposure to KCl and K2SO4 suppressed or even blocked sucrose degradation, thus leading to strong accumulation of sucrose in shoots, which then probably inhibited photosynthesis via feedback inhibition. Moreover, K+ was more accumulated in shoots than Na+ after corresponding potassium or sodium salt treatments, thus resulting in decreased Ca2+ and Mg2+ concentrations in response to KCl and K2SO4. However, K2SO4 caused more severe toxicity symptoms than iso‐osmotic KCl, even when the K+ level was lower in K2SO4‐treated plants. We found that Na2SO4 and K2SO4 induced strong accumulation of tricarboxylic acid intermediates, especially fumarate and succinate which might induce oxidative stress. Thus, the severe toxicity symptoms found in K2SO4‐treated plants were also attributed to SO 4 2 - in addition to the massive accumulation of K+.  相似文献   

11.
Effect of high NaCl concentration in the nutrient medium on transpiration, abscisic acid, cytokinin and proline content of two soybean varieties With the differentially salt-sensitive soybean varieties ?Lee”? and ?Jackson”? the effect of salinization on transpiration, Cl? and Na+ accumulation, and on abscisic acid (ABA), cytokinin and proline content was investigated. Salinization with 75 mM NaCl in the nutrient medium drastically inhibited the transpiration (about 40%) of both varieties but more so with the variety ?Jackson”?. Nevertheless this variety translocated substantially more Cl? into the shoot than ?Lee”?. However, ?Lee”? accumulated more Cl? into the roots and thus was able to effectively protect the shoot against a toxic Cl? concentration. The Na+ distribution in the roots and shoots was nearly the same in both varieties. The ABA content of the leaves of both varieties increased 5-fold to 1200 ng × g? dry weight after 48 h of salt stress. About the same time transpiration of the salt-stressed plants reached a minimum. Between 48 and 168 h the ABA content of ?Lee”? dropped to about half. The ABA level in ?Jackson”? remained higher which indicated that the shoot was stressed more intensely and/or longer. The results do not imply a causal relationship between the ABA concentration in the leaves and the exclusion of C1? from the shoot of ?Lee”?. The cytokinin concentration of the two soybean varieties was not significantly affected by salinization. The proline content in the leaves increased markedly with salt stress in both varieties but much more so in ?Jackson”?. Proline content in the leaves increased from about 1.8 μmoles × g?1 dr. w. before salt stress to 24.7 μmoles × g?1 dr. w. after 168 h of stress. However, the proline concentration dropped to nearly the initial level within 48 h after a 120 h salt stress treatment was discontinued and the plants were returned to a control solution. In ?Lee”? salinization only doubled the amount of proline found initially. The highest value was observed after 120 h of salinization.  相似文献   

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.
钾肥用量和品种对桑叶生产及蚕茧质量的影响   总被引:3,自引:0,他引:3  
通过为期 4年的田间施肥试验和 1季养蚕试验 ,研究了钾肥用量和钾肥品种对桑叶产量、品质、养分吸收和蚕茧质量的影响。结果表明 ,施K2 O 1 5 0、30 0、375kghm-2 a-1 处理分别比不施K肥年均增产桑叶 2 3.9%、31 .7%、36 .0 %;等量钾肥时 ,KCl对桑叶增产效果基本等同于K2 SO4;施钾增产效果有逐年增加趋势 ,同时钾肥施用表现后效。施钾明显提高桑叶中N、K和S(K2 SO4为钾源时 )含量 ,而降低Ca、Mg和Zn含量 ,对P含量影响不大。结果显示 ,钾肥施用大幅度促进了桑树对各种养分的吸收 ,从而提高了肥料利用率。施钾明显促进桑叶品质的改善 ,随着钾肥用量增加 ,桑叶中必需氨基酸、氨基酸总量、蛋白质、糖分和油脂含量均呈增加趋势。KCl施用也能提高桑叶品质 ,但效果比K2 SO4差。蚕茧质量测试结果表明 ,桑树施钾后对喂养的蚕茧品质产生正面影响 ,蚕重、全茧量、上茧率、茧丝长、解舒率、茧丝净度等指标均因施钾而提高 ,高量钾比低量钾效果好 ,在等量钾用量时K2 SO4对蚕茧质量的促进作用明显好于KCl。  相似文献   

14.
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   

15.
燕麦幼苗对氯化钠和氯化钾胁迫的生理响应差异   总被引:1,自引:0,他引:1  
为探讨燕麦对NaCl和KCl胁迫的生理响应差异,采用水培法,研究了不同浓度NaCl和KCl胁迫对幼苗生长,活性氧代谢和渗透调节的影响。结果表明:(1)在75和150mmol/L浓度下,NaCl胁迫对燕麦幼苗的膜脂过氧化伤害和生长抑制大于KCl胁迫。NaCl胁迫下叶片中的超氧化物岐化酶(SOD),过氧化氢酶(CAT)活性及可溶性蛋白、可溶性糖和脯氨酸含量低于KCl胁迫;当浓度增大到225mmol/L时,KCl胁迫叶片中O-2.,H2O2,丙二醛(MDA),可溶性蛋白和可溶性糖含量显著大于NaCl胁迫,而SOD,抗坏血酸过氧化物酶(APX)活性及谷胱甘肽(GSH)含量则相反。(2)225mmol/L KCl和NaCl处理的植株叶片水势分别为-0.867和-1.034 MPa,渗透势分别为-1.409和-1.252 MPa,说明KCl对燕麦的更强伤害不是渗透胁迫所致;经225mmol/L KCl胁迫后,燕麦叶片中Na+含量下降至对照的36.5%,而K+含量上升为对照的1.49倍,而补充20mmol/L NaCl显著提高了225mmol/L KCl胁迫下叶片Na+的含量及SOD,APX活性,降低了K+,H2O2,O-2.和MDA含量,说明离子毒害引起的活性氧积累可能是高浓度KCl胁迫对燕麦幼苗伤害大于NaCl胁迫的重要原因。  相似文献   

16.
Mineral regulation of two soybean varieties Jackson and Lee was investigated in long term water culture experiments using saline solutions. The effects of extreme K:Na ratios using chloride and sulfate as counterions were studied in the early stages of salinity.

The growth rates of both varieties were not affected by salinization. A K+ stimulated, intensive acropetal Cl translocation was observed in the salt sensitive variety Jackson. The varieties did not differ in Na+ translocation and in the suppression of Ca2+ and Mg2+ in the leaves. But the effect of the nature of salinization indicates already differences in Na uptake and translocation of the cultivars.

The avoidance of Cl, but also of Ha+, in connection with influences of the resulting ionic imbalance on metabolic pathways are probably the most causative factors for the different tolerance to salinity of the two soybean varieties.  相似文献   

17.
Abstract

Sensitivity to chloride was measured in soybean [Glycine max (L.) Merr.] cultivars Rinjani, Lokon, and Merbabu from Indonesia, and Lee from the United States. Plants were grown in solution culture to which KCl (0, 50, or 100 mol m‐3) was added gradually during days 7–14 after emergence. Excess KCl reduced growth, measured as leaf area, shoot and root biomasses, total biomass, and root/shoot ratio in 24‐day‐old plants of all cultivars. The cultivar x KCl treatment interaction was significant for all growth parameters. The order of chloride tolerance at 50 mol m‐3 Cl, based on the mean of all growth parameters relative to the control, was Lee>Rinjani>Lokon=Merbabu. In the 50 mol m‐3 Cl treatment Lee excluded Cl from the leaves, and accumulated Cl in the roots; Lokon, Rinjani, and Merbabu excluded less Cl from the leaves. At 100 mol m‐3 KCl, cultivar Lee lost its capacity to exclude Cl from the leaves and its growth was poor. Chloride exclusion from the leaves at 100 mol m‐3 KCl was most effective in Lokon, which corresponded to the relatively good growth of this cultivar in the high KCl treatment.  相似文献   

18.
《Journal of plant nutrition》2013,36(12):2689-2704
ABSTRACT

Salinity is among the most widespread and prevalent problems in irrigated agriculture. Many members of the family Chenopodiaceae are classified as salt tolerant. One member of this family, which is of increasing interest, is quinoa (Chenopodium quinoa Willd.) which is able to grow on poorer soils. Salinity sensitivity studies of quinoa were conducted in the greenhouse on the cultivar, “Andean Hybrid” to determine if quinoa had useful mechanisms for salt tolerant studies. For salt treatment we used a salinity composition that would occur in a typical soil in the San Joaquin Valley of California using drainage waters for irrigation. Salinity treatments (ECi ) ranging from 3, 7, 11, to 19?dS?m?1 were achieved by adding MgSO4, Na2SO4, NaCl, and CaCl2 to the base nutrient solution. These salts were added incrementally over a four-day period to avoid osmotic shock to the seedlings. The base nutrient solution without added salt served as the non-saline control solution (3?dS?m?1). Solution pH was uncontrolled and ranged from 7.7 to 8.0. For comparative purposes, we also examined Yecora Rojo, a semi-dwarf wheat, Triticum aestivum L. With respect to salinity effects on growth in quinoa, we found no significant reduction in plant height or fresh weight until the electrical conductivity exceeded 11?dS?m?1. The growth was characteristic of a halophyte with a significant increase in leaf area at 11?dS?m?1 as compared with 3?dS?m?1 controls. As to wheat, plant fresh and dry weight, canopy height, and leaf area did not differ between controls (3?dS?m?1) and plants grown at 7?dS?m?1. Beyond this threshold, however, plant growth declined. While both quinoa and wheat exhibited increasing Na+ accumulation with increasing salinity levels, the percentage increase was greater in wheat. Examination of ion ratios indicated that K+:Na+ ratio decreased with increasing salinity in both species. The decrease was more dramatic in wheat. A similar observation was also made with respect to the Ca2+:Na+ ratios. However, a difference between the two species was found with respect to changes in the level of K+ in the plant. In quinoa, leaf K+ levels measured at 19?dS?m?1 had decreased by only 7% compared with controls. Stem K+ levels were not significantly affected. In wheat, shoot K+ levels had decreased by almost 40% at 19?dS?m?1. Correlated with these findings, we measured no change in the K+:Na+ selectivity with increasing salinity in quinoa leaves and only a small increase in stems. In wheat however, K+:Na+ selectivity at 3?dS?m?1 was much higher than in quinoa and decreased significantly across the four salinity levels tested. A similar situation was also noted with Ca2+:Na+ selectivity. We concluded that the greater salt tolerance found in quinoa relative to wheat may be due to a variety of mechanisms.  相似文献   

19.
The relation between activity of soluble acid invertase and sucrose content in leaves of young bushbeans (salt sensitive) and sugarbeets (salt tolerant) and ion‐specific effects of salinity environment were investigated. For comparison the response of isolated invertase from both plant species to ion combination and ion concentration was investigated. The plants were grown in water culture under controlled conditions.

In busbean leaves invertase activity decreased while sucrose increased. K+ with Cl as counterion was most effective “in vivo”;. However, there was little change in invertase activity or sucrose content in sugarbeet leaves. Independent of the origin of the enzyme, invertase activity was not affected by either ion concentration or ion combination “in vitro”;. Acid invertase might be a key enzyme in the utilization of carbohydrates. The ionic effect on acid invertase activity and carbohydrate content in intact plant tissue could be a possible indicator of salt tolerance of crops.  相似文献   


20.
The quality of irrigation water used for greenhouse crop production can strongly influence plant growth. However, the effect on plant growth is probably a combination of water quality and the type of growing media used. To determine the effect of saline and alkaline irrigation water on plant growth and nutrition, pansy and impatiens were grown in peat, peat:pine bark, and pine bark media under standard greenhouse conditions. Salinity treatments of 0, 100 and OmgL‐1 NaCl: CaCl2 and alkalinity treatments of 0, 100, 200, 300, and 400 mg L‐1 NaHCO3 were applied at every irrigation. Salinity levels at 100 mg L‐1 and greater caused necrosis of leaf edges, upward curling of leaves, and reduced flower number for pansy. Treatment symptoms for impatiens were reduced growth, general chlorosis, and reduced flower number. These treatment symptoms increased in severity for plants grown in pine bark. Alkalinity levels at 200 mg L‐1 and greater caused decreased flower number, necrosis of leaf edges, and downward cupping of leaves of pansy. Treatments symptoms of impatiens were general chlorosis, water‐soaked appearance of leaves and leaf abscission. Elemental concentrations of sodium (Na+), chloride (Cl), calcium (Ca++), magnesium (Mg++), and potassium (K+) varied in media solution and tissue with symptom and treatment.  相似文献   

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