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1.
《Plant Production Science》2013,16(4):453-461
Abstract

Effects of NaCl on the growth, ion content, root cap structure and Casparian band development were examined in four rice (Oryza sativa L.) cultivars with different salt resistance (salt-sensitive indica-type IR 24 and japonica-type Nipponbare and salt-resistant indica-type Nona Bokra and Pokkali). Experiments were conducted to find the differences in salinity resistance during early seedling and developed seedling stages among the cultivars. For salinity treatment, sodium chloride (NaCl) was added to nutrient solution at concentrations of 0, 25 and 50 mM for 7 days from germination to the 7th day (early seedling stage) or from the 7th day to 14th day (developed seedling stage). Growth inhibition by salinity was more prominent in the early seedling stage than in the developed seedling stage. Based on the growth, the order of the sensitivity was IR24 > Nipponbare > Nona Bokra > Pokkali. The growth of NaCl-treated rice cultivars relative to control was significantly and negatively correlated with the Na+ content and Na+/K+ ratio in roots and shoots in both stages. Scanning electron microscopic observation revealed that the root cap tissues proliferated and extended to the basal part of the root tip by salinity. The length of root cap was, however, reduced by 50 mM NaCl in sensitive cultivars due to peeling off. An endodermal Casparian band was formed in the basal region of the root tip. Development of the Casparian band was more prominent in sensitive cultivars than in tolerant cultivars. Root cap proliferation might be related to NaCl resistance in rice seedlings, but the Casparian band may not function efficiently in Na+ exclusion. Essentially the present results suggest that exclusion of Na+ from roots plays a critical role in expression of Na+ resistance in rice seedlings and the root cap is important for Na+ exclusion.  相似文献   

2.
《Plant Production Science》2013,16(3):215-218
Abstract

Distribution of Na+ along the root axis under salinity stress was analyzed in two rice (Oryza sativa L.) cultivars with different salt resistance (salt-sensitive IR 24 and salt-resistant Pokkali). Rice plants were grown hydroponically and NaCl was applied with nutrient solution at concentrations of 0, 25 and 50 mM for 7 d after germination. The distribution of Na+ in roots under salinity was analyzed by the cryo time-of-flight secondary ion mass spectrometry (cryo TOF-SIMS). The Na+ content in the root was higher in salt-sensitive IR 24 than in salt-resistant Pokkali under NaCl stress. The content was highest at the root tip and was decreased basipetally along the root axis. The difference in Na+ content between the cultivars was apparent in all regions from the root tip.  相似文献   

3.
《Plant Production Science》2013,16(2):164-168
  相似文献   

4.
《Plant Production Science》2013,16(5):533-538
Abstract

Common buckwheat (Fagopyrum esculentum Moench cv. Tsushima) and Tartary buckwheat (F. tataricum (L.) Gaertn. cv. Pontivy) were grown in a nutrient solution with or without added NaCl to investigate interspecific differences in their responses to salinity, based on their dry-matter production. The mechanism of salt tolerance was also studied. Addition of 100 mM NaCl to the culture solution (salt treatment) lowered the plant growth rate to 48% and 16% of the control in Tsushima and Pontivy, respectively, and decreased the net assimilation rate and mean leaf area of Pontivy more severely than in Tsushima. The salt treatment decreased the leaf growth rate and leaf area per leaf to 30% and 72% of the control, respectively, in Tsushima, and to 12% and 52%, respectively, in Pontivy. It decreased the photosynthetic rate to 67% and 35% of the control, and stomatal conductance to 25% and 15% of the control in Tsushima and Pontivy, respectively. It also decreased the transpiration rate to 41% and 30% of the control in Tsushima and Pontivy, respectively, and increased the wateruse efficiency 1.6 times in Tsushima, but did not influence the wateruse efficiency in Pontivy. In the saline solution, the accumulation of Na+ in leaves and stem was greater in Pontivy than in Tsushima, but that in the roots, was greater in Tsushima than in Pontivy. In both species, Na+ accumulated rapidly in the leaves after removal of the roots in the saline solution. We conclude that the difference in salt tolerance between common and Tartary buckwheat may result from the difference in accumulation of Na+ in leaves and absorption of Na+ by the roots.  相似文献   

5.
Summary

Use of saline drainage water for crop irrigation was evaluated as a means of decreasing its volume. Results of a nine-year crop rotation (cotton-cotton-safflower, × 3) in which only the cotton was irrigated with drainage water of 400, 1,500, 3,000, 4,500, 6,000, and 9,000 ppm total dissolved salts are presented. The different salinity levels of irrigation waters were achieved by mixing nonsaline canal water (400 ppm) and saline drainage water. Cotton lint yields were not affected by increased salinity level of the irrigation water for the first two years. Detrimental effects became evident in the third cotton crop with increasing severity in later years. In the fifth year of cotton (seventh year of the study), lint yields were adversely affected by waters of salinity greater than 3,000 ppm. However, fiber quality remained unaffected at all levels of irrigation water salinity. The reductions in lint yield appeared to be a function of time and the salinity level of applied water. Shoot height and biomass were reduced by the irrigation water salinity before lint yields. Stand establishment appeared to be the most sensitive to salinity and was perhaps the main reason for yield reduction. Increase in irrigation water salinity increased Na+ content of leaf blades and petioles and decreased K+/Na+ ratio of leaf blades and petioles. The study showed that irrigation waters of up to 3,000 ppm salinity may be used for four years without any yield reductions, as long as some leaching occurs through preplant irrigations with low salinity water. Data on crop growth and development and ionic content collected over the nine year period are presented.  相似文献   

6.
《Plant Production Science》2013,16(4):313-316
Abstract

One hundred and fifteen clones of zoysia spp. collected around the coast of Taiwan were examined for the variation of salinity tolerance. zoysia spp., native of Taiwan, showed a wide range of salinity tolerance among the clones collected from various regions. The clones from the regions with higher annual rainfall and limestone showed lower NaCl tolerance, and some of them showed 100% shoot mortality under 3% NaCl within 3 weeks. On the contrary, some clones from the regions with lower rainfall retained a few green leaves even at 7.5% NaCl for 3 weeks. A positive correlation was observed between the percentages of 100% shoot mortality in clones treated with 6% NaCl and the rainfall of the regions where the clones were collected. However, based on the same level of rainfall, the clones collected from the limestone region showed higher percentages of shoot mortality than those collected from the other regions. Using four clones including NaCl-tolerant and NaCl-sensitive, the effect of Ca on the salinity stress was further examined. Addition of CaCl2 to the nutrient solution could alleviate the leaf firing and electrolyte leakage from the leaf of Zoysia clones caused by NaCl. The geographical variation of salinity tolerance in zoysia might be caused by the differences in the salt and calcium concentrations in soil, which were affected by rainfall and geology of their habitats.  相似文献   

7.
利用隶属函数值法对玉米成熟期抗旱性的综合评价   总被引：1，自引：0，他引：1  
张会丽  许兴  朱林 《玉米科学》2017,25(4):32-39
以10个不同基因型玉米为试验材料,在宁夏中部干旱带,通过测定不同品种成熟期的K~+/Na~+、光合气体交换参数、农艺性状及产量性状等指标进行抗旱性鉴定,并利用主成分分析和隶属函数法对其抗旱性强弱进行综合评价。结果表明,干旱胁迫地和对照田中,各参试品种的光合特征参数、K~+/Na~+及形态性状等均有明显差异,且干旱胁迫条件下的净光合速率(P_n)、株高、产量均显著低于对照(P0.05)。同一品种不同器官的K~+/Na~+值表现为茎基茎叶根,表明植株体内的离子吸收和运输具有选择性,茎基具有贮存K~+的作用,根具有贮存Na~+的功能。不同基因型玉米品种的抗旱能力根据综合评价值(D值)大小,综合评价其抗旱性强弱顺序为A111-3/H242HoViY1北21/A58A3/A18高WY2宁3/1522H237/A18桂青贮1号H237/1506A3/A18。  相似文献   

8.
Seabuckthorn (Hippophae rhamnoides L.) is uniquely capable of growing well under various extreme environmental conditions, such as water deficit, salt stress, low temperature, and high altitude. It is of economic value and its berries are used in cosmetics and pharmaceutical products. In this study, we compared the effects of salt stresses (9:1 molar ratio of NaCl to Na2SO4, pH 6.48–6.65) and alkali stresses (9:1 molar ratio of NaHCO3 to Na2CO3, pH 8.70–8.88) on the levels of inorganic ions and organic acids in H. rhamnoides L. to elucidate the physiological mechanism by which it tolerates salt or alkali stress (high pH). The results showed that, in leaves and stems under alkali stress, the Na+ content increased to a much greater extent than under salt stress. Neither salt nor alkali stress decreased the K+ content in leaves and stems; however, in roots, the K+ content decreased sharply with increasing alkali stress, whereas it remained relatively unchanged with increasing salt stress. This revealed a specific mechanism of absorption or transport for Na+ and K+ that was affected strongly by alkali stress. The results indicated that accumulation of organic acid (OA) was a central adaptive mechanism by which H. rhamnoides maintained intracellular ionic balance under alkali stress. OA may play different roles in different organs during adaptation to alkali stress, and its percentage contribution to total negative charge was higher in leaf than in stem. H. rhamnoides accumulated mainly malate, oxalate, and citrate in leaves and stems; however, in roots, less malate and citrate was accumulated, and acetate accumulation was enhanced significantly, which indicated that roots and shoots use different mechanisms to modulate OA metabolism.  相似文献   

9.
A greenhouse study was conducted to determine the effects of waters differing in salt composition on growth and selenium (Se) accumulation by lesquerella (Lesquerella fendleri Gray S. Wats.). Plants were established by direct seeding into sand cultures and irrigated with solutions containing either (a) Cl− as the dominant anion or (b) a mixture of salts of SO42− and Cl−. Four treatments of each salinity type were imposed. Electrical conductivities of the irrigation waters were 1.7, 4, 8, and 13 dS m−1. Two months after salinization, Se (l mg l−1, 12.7 μM) was added to all solutions as Na2SeO4. Shoot growth was significantly reduced by increasing Cl-salinity. Regardless of salinity type, concentrations of Ca2+, Mg2+, Cl−, total-S, and Se were higher in the leaves than the stems, whereas K+ and Na+ were higher in the stem. Leaf-Se concentrations were not significantly affected by Cl-based irrigation waters, averaging 503 mg Se kg−1 dry wt across salinity levels, whereas leaf-Se decreased consistently and significantly from 218 to 13 mg kg−1 as mixed salt salinity increased. The dramatic reduction in Se was attributed to SO42−:SeO42− competition during plant uptake. The strong Se-accumulating ability of lesquerella suggests that the crop should be further evaluated as a potentially valuable phytoremediator of Se-contaminated soils and waters of low to moderate salinity in areas where the dominant anion in the substrate is Cl−.  相似文献   

10.
《Plant Production Science》2013,16(2):169-176
Abstract

The effect of NaCl stress on the structure of leaf chloroplasts was investigated in several NAD-Malic enzyme (NAD-ME) and phosphoenolpyruvate carboxykinase (PCK) type C4 plant species. Seedlings of the monocot species, except Zoysia japonica, grown in 300 mL pots were subjected to salt stress by adding 50 mL of 3% NaCl solution per day to the soil for 5 d after the fourth leaf blades were fully developed. Z. japonica and the dicot species, Amaranthus tricolor, were also treated with 3% NaCl in a similar manner from 5 wk after germination. Salt stress negatively affected the growth, chlorophyll content and chloroplast structure in all the species. At the ultrastructure level, swelling of thylakoids and disruption of envelopes were more or less observed in mesophyll cell (MC) chloroplasts after salt treatment. The structure of bundle sheath cell (BSC) chloroplasts, on the other hand, was hardly damaged under salt condition although stromal and starch areas were considerably decreased. Furthermore, salinity induced granal development in BSC chloroplasts in most species; the number of thylakoids per granum, granal indices and appressed thylakoid density in salt-treated plants were generally higher than those in control. Since the similar responses have also been reported in all NADP-ME type C4 species investigated in our previous study, the high sensitivity to salt stress in MC chloroplasts and the granal development in BSC chloroplasts by salinity were considered to be common phenomena in all three C4 subtypes.  相似文献   

11.
复合盐胁迫对小麦萌发的影响及耐盐阈值的筛选   总被引：2，自引：0，他引：2  
为了解Na2SO4和NaCl组成的复合盐对小麦萌发期的胁迫效应,选择5个耐盐性不同的春小麦品种进行复合盐胁迫处理,研究在不同浓度复合盐胁迫下,春小麦品种在发芽势、发芽率、苗高、根数、主根长和苗鲜重等指标上的差异,并采用多重比较和回归分析筛选最适复合盐萌发期处理浓度。结果表明,随着复合盐各盐分浓度升高,小麦萌发期各指标的相对耐盐系数急剧下降,且发芽势、发芽率、苗高、主根长和苗鲜重在不同浓度处理间差异极显著;但复合盐对小麦根数的影响较小,在低盐浓度下差异不显著。在Na2SO4浓度为0.05mol.L-1、NaCl浓度为0.1mol.L-1时,5个品种的发芽率、苗鲜重、苗高的相对耐盐系数在50%左右,发芽势和主根长趋近于30%,同时种子保持较高的活力,可以作为小麦萌发期耐盐鉴定的适宜复合盐胁迫浓度。  相似文献   

12.
《Field Crops Research》2005,91(2-3):345-354
The performance of selected salt-tolerant genotypes of durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.], derived from field and in vitro assessment methods, was evaluated under greenhouse and field conditions. Eight durum wheat genotypes comprising three salt-tolerant genotypes and one salt-sensitive genotype selected from each of the methods were used. This study was conducted under both saline and non-saline field conditions as well as under greenhouse condition with salinized solution culture at 0 mM (control), 75 and 150 mM NaCl (concentrations) using supplemental Ca2+. Days to heading, days to maturity, plant height, number of grains per spike, grain weight per spike, 1000 grain weight, number of spikes per m2, grain yield and harvest index were recorded in the field experiments. Plant dry weight, Na+, K+ and Ca2+ accumulated in the hydroponically grown seedlings were measured 20 days after salinity treatments. In spite of the smaller range of genotypes used by the in vitro screening method, tolerant genotypes screened by the in vitro method (ITGs) performed comparably with those of the field-derived tolerant genotypes (FTGs) for grain yield under saline field conditions. Field salinity significantly reduced (P < 0.01) means of all traits averaged on eight tested genotypes. In vitro salt-tolerant genotypes Dipper-6 and Prion-1 produced the highest dry weight and K+/Na+ ratio under salt stress conditions (150 mM NaCl) in the greenhouse. Although dry matter correlated with the grain yield (R2 = 0.37), the regression coefficient was higher for shoot K+/Na+ ratio (R2 = 0.44). Dipper-6 (ITG) and Prion-1 (ITG) genotypes have been ranked superior while Massara-1 (ISG) was inferior for salt tolerance in the regression analysis. However, based on grain yield reduction Ajaia/Hora/Jro/3/Gan (FTG) and PI40100 (ITG) were the most tolerant having 58% and 60% reduction, respectively.  相似文献   

13.
采用水培法研究外源硅对盐胁迫下玉米幼苗可溶性糖、游离氨基酸等渗透调节物质含量的影响。结果表明,盐胁迫下适量的增加硅供应能增加叶片和根系中渗透调节物质含量,其中根系中游离氨基酸、可溶性蛋白和可溶性糖含量的增加幅度大于叶片;同时能增加玉米幼苗各器官K+的含量,降低不同部位Na+含量,维持玉米幼苗体内的离子平衡。研究表明,硅参与盐胁迫下渗透调节物质在植物中的运输和分配,适宜浓度的硅能提高玉米耐盐性。  相似文献   

14.
《Plant Production Science》2013,16(5):567-577
Abstract

The changes in chloroplast ultrastructure and the contents of chlorophyll, Na and K in response to salinity stress were investigated in leaves of maize, an NADP-malic enzyme-type C4 plant species possessing dimorphic chloroplasts. The seedlings were treated with 0, 1, 2 or 3% NaCl for three or five days under a light or dark condition. In both light and dark conditions, the dry weight of salt-treated plants decreased as NaCl concentration increased. Chlorophyll and K contents of the second leaf blade decreased as NaCl concentration increased under the light condition but not under the dark condition. Na content of the second leaf blade was significantly higher at high NaCl concentrations under both light and dark conditions. However, Na content was much lower under the dark condition than light condition. Higher concentrations (2 and 3%) of NaCl significantly increased the size of plastoglobules, decreased the number and size of starch granules and altered the chloroplast ultrastructure. Under the light condition, mesophyll cell (MC) chloroplasts appeared more sensitive to the damaging effect of salinity than the bundle sheath cell (BSC) chloroplasts. MC chloroplasts became more globular in shape and showed swollen and disorganized thylakoids and reduced thickness of grana by salinity. BSC chloroplasts were less affected by salinity than MC chloroplasts. Although chloroplast size and number and size of starch granules were reduced, there was no structural distortion in the thylakoids of BSC chloroplasts. However, the thickness of grana was increased by salinity. Under the dark condition, the chloroplast structure was less affected by salinity. Though the envelope of BSC chloroplasts was occasionally damaged, the thylakoids in both MC and BSC chloroplasts were preserved under salinity stress. The present study suggests that the chloroplast damage caused by salinity is light-dependent and MC chloroplasts are more sensitive to salinity than BSC chloroplasts.  相似文献   

15.
A rapid quantification method for leaf sodium (Na+) and potassium (K+) concentrations was developed using a compact ion meter. Leaf ion concentrations were evaluated for species of Vigna vexillata (L.) A. Rich. after two weeks of treatment with 0–200 mM of sodium chloride. To compare the ion extraction efficiency, extraction solutions of distilled water and ammonium acetate were tested. The ion concentrations of extracts obtained by both solutions were measured using an ion meter, and the values were validated using ion chromatography. For both extraction solutions, the ion meter values were highly correlated with those of the ion chromatograph. However, correlations between ion meter and chromatograph values were largely different for Na+ and K+. The rapid quantification of ion concentrations using an ion meter developed in this study was successfully utilized for evaluating differences in leaf Na+ concentrations, K+ concentrations, and K+/Na+ ratio in species of V. vexillata.  相似文献   

16.
研究不同供磷水平对NaCl胁迫下玉米幼苗有机渗透调节物质和离子含量的影响。结果表明,盐胁迫下低磷处理玉米幼苗叶片中可溶性糖和游离氨基酸增加,根系中显著降低;增加供磷水平,叶片中可溶性糖和游离氨基酸含量下降,根系中含量上升,同时叶片和根系中可溶性蛋白含量增加。磷可降低盐胁迫下玉米幼苗各器官中的Na~+含量,同时增加各器官的K~+、Ca~(2+)和Mg~(2+)含量,降低Na~+/K~+与Na~+/Ca~(2+)比值。磷有助于维持植株的碳氮代谢平衡,促进有机渗透调节物质的运输与分配,改善各器官的离子平衡,增强植株的渗透调节能力,从而缓解盐胁迫带来的伤害。  相似文献   

17.
为研究盐胁迫下小麦维持钾、钠平衡的生理机制,以耐盐小麦沧麦6005和盐敏感小麦矮抗58为材料,利用TEA、NEM、Ba(NO_3)_2三种药物分别抑制钾离子通道、钾载体及非选择性阳离子通道,测定正常及盐胁迫下小麦叶片K~+、Na~+含量,比较耐盐性不同的小麦品种在K~+、Na~+吸收中的差异。结果显示,盐胁迫下,沧麦6005和矮抗58叶片K~+含量下降,Na~+含量增加;沧麦6005叶片Na~+含量低于矮抗58,K~+/Na~+比值高于矮抗58。正常条件下,NEM、TEA处理均可降低沧麦6005和矮抗58叶片K~+含量,NEM处理较TEA处理效果更为明显;TEA处理显著降低了盐胁迫下矮抗58叶片K~+含量,而NEM处理则明显降低了盐胁迫下沧麦6005的叶片K~+含量;TEA、NEM、Ba(NO_3)_2处理降低了盐胁迫下矮抗58叶片Na~+含量,仅NEM处理降低了沧麦6005叶片Na~+含量。综上所述,正常条件下,钾载体是小麦K~+吸收的主要方式;盐胁迫下,耐盐品种和盐敏感品种K~+吸收途径不同,耐盐品种的NSCCs和钾离子通道具有更强的"拒钠"能力。  相似文献   

18.
Elevated Na+ levels in agricultural lands are increasingly becoming a serious threat to the world agriculture. Plants suffer osmotic and ionic stress under high salinity due to the salts accumulated at the outside of roots and those accumulated at the inside of the plant cells, respectively. Mechanisms of salinity tolerance in plants have been extensively studied and in the recent years these studies focus on the function of key enzymes and plant morphological traits. Here, we provide an updated overview of salt tolerant mechanisms in glycophytes with a particular interest in rice (Oryza sativa) plants. Protective mechanisms that prevent water loss due to the increased osmotic pressure, the development of Na+ toxicity on essential cellular metabolisms, and the movement of ions via the apoplastic pathway (i.e. apoplastic barriers) are described here in detail.  相似文献   

19.
《Plant Production Science》2013,16(1):139-145
Abstract

The seedlings of Oryza sativa L. cv. Nipponbare grown by hydroponic culture for 3 wks were treated with 75, 100, 150 and 200 mM NaCl for 14, 14, 6 and 3 days, respectively, and examined for chloroplast ultrastructure in the region where chlorophyll fluorescence had been recorded. NaCl treatment decreased the ratio of variable to maximum chlorophyll fluorescence yield (Fv/Fm) and caused swelling of thylakoids. The swelling of thylakoids was quantified by the percentage of the length of swollen thylakoids to the total length of thylakoids. This value was increased with increasing NaCl concentration. Although Fv/Fm decreased at all concentrations of NaCl, the minimal fluorescence yield F0 was not increased by the treatment with 75 or 100 mM NaCl. The percentage of the length of swelling was low at 75 and 100 mM NaCl. On the other hand, F0 increased and the swelling of thylakoids was prominent with 150 and 200 mM NaCl treatment. These results suggest that the decrease in Fv/Fm due to the increase in F0 under salt stress correlates with the ultrastructural damage. The decrease in Fv/Fm due to the increase in F0 is expected to be useful as an indicator to evaluate the damage in chloroplasts, especially in thylakoid membranes, under salinity.  相似文献   

20.
Abstract

It is important to measure the individual leaf area and leaf area index (LAI) of sago palm (Metroxylon sagu Rottb.) to determine the appropriate planting density and maintain populations that are highly productive with regard to starch production. However, the accurate estimation of sago leaf area from the entire leaf profile or the projecting area of the plant is not possible. Thus, we developed a method for estimating leaf area of sago palm after trunk formationby integrating the leaflet areas. All leaflets were diagrammatically converted to rectangles, each having the same area asthat of the corresponding leaflet, and these rectangles were arranged on the rachis to initiate the shape of a leaf without overlapping leaflets and gaps between their bases and between their tips. The leaf shape thus produced by the arrangement of these rectangles was represented as ellipsoidal in the apical half and as trapezoidal in the basal half. The ratiosof the estimated to the actually measured area of the apical and the basal half of the leaf were 99?107% and 94?108%, respectively. The ratio of the estimated area of the whole leaf to the measured area was 98?104%. From these results, the method for estimating the whole leaf area by converting the leaflets diagrammatically to rectangles, andcalculating the area as the sum of the ellipsoidal apical half and trapezoidal basal half, is considered to be accurate and simple.  相似文献   

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