水稻耐盐性的机理

Shaheen Basmati was evolved as a salt tolerant fine rice variety by the Soil Salinity Research Institute,Pindi Bhattian, Pakistan. Water culture studies were conducted to investigate the physiological mechanism exercised by this variety in particular and rice plant in general to face the saline environment. Performance of this rice variety and the concentration and uptake of ions were studied under stress of three salinity levels(30, 60 and 90 mmolL^-1) created with NaC1. Recorded data indicated that shoot dry matter was not significantly affected by all the three levels of salinity. However, NaC1 levels of 60 and 90 mmol L^-1 affected the root dry matter significantly. Sodium concentration and uptake was enhanced significantly in root and shoot at the first level of salinity (30 mmol L^-1) but thereafter the differences were non-significant, indicating the preferential absorption of this cation. The K concentration decreased significantly in shoots at all the levels. The impact was less pronounced in roots as far as K absorption was concerned. The effect on Ca and Mg concentrations was not significant. The values of K:Na, Ca:Na and (Ca Mg):Na ratios in shoot and root were comparatively low under stress conditions, indicating that selective ion absorption may be the principal salt tolerance mechanism of variety Shaheen Basmati when grown in a saline medium.     

咸水畦灌棉花耐盐性鉴定指标与耐盐特征值研究

为了充分利用浅层地下咸水,通过5 a的咸水畦灌播前造墒大田试验,分析了不同程度盐分胁迫(1(对照)、2、4、6、8、10 g/L)与棉花生长指标和籽棉产量的响应关系,得出不同矿化度咸水播前造墒条件下棉花的耐盐性鉴定指标及耐盐特征值。结果显示,相对出苗率、相对株高、相对叶面积、相对地上部干物质质量、相对果枝数、相对成铃数和相对蕾花铃最大值均可以作为棉花的耐盐性鉴定指标,其中相对株高易于观测,盐害指示效果好,因此作为推荐使用耐盐性鉴定指标。同时,灌溉水矿化度控制在5.48 g/L以下时,咸水造墒连续灌溉5 a后,在产量与对照相比不减产。     

Between and within cultivar variability in salt tolerance in lucerne, (Medicago sativa L.)

Summary The response of two-week-old seedlings of 35 cultivars of lucerne (Medicago sativa L.) to increasing NaCl concentrations was assessed in solution culture under growth room conditions. Shoot length, used as the criterion for assessing salt tolerance, was found to decrease significantly with increasing NaCl concentration for all cultivars, but there was considerable variation in response between, and within cultivars. It is concluded that selection between and within cultivars should lead to increased salt tolerance in this species.     

一种新的提高树苗盐容量的移植方法

The influence of quinclorac (3,7-dichloroquinoline-8-carboxylic acid) on enzyme activities in flooded paddy soils was assessed under laboratory conditions. The enzymes differed markedly in their response to quinclorac. Quinclorac inhibited proteinase, hydrogen peroxidase, phosphorylase, and urease activities. The higher the concentration of quinclorac applied, the more significant the inhibition to these observed activities with a longer time required to recover to the level of the control. However, soils supplemented with quinclorac were nonpersistent for proteinase~ phosphorylase and urease as opposed to soils without quinclorac. Dehydrogenase activity was also sensitive to quinclorac. Three soil samples with concentrations of quinclorac higher than 1 μg g^-1 soil declined to less than 20% of that in the control. However, the highest dehydrogenase activity (up to 3.28-fold) was detected in soils with 2 μg g^-1 soil quinclorac on the 25th day after treatment. Quinclorac had a relatively mild effect on saccharase activity at the concentrations used in this experiment and a stimulatory one on soil respiration when added to soil at normal field concentrations. Nonetheless it was inhibited at higher concentrations in paddy soils. Quinclorac is still relatively safe to the soil ecosystem when applied at a normal concentration (0.67 μg g^-1 dried soil) but may have some effects on soil enzymes at higher concentrations.     

河套灌区玉米耐盐性分析及生态适宜区划分

为了探讨河套灌区盐碱地玉米对根区土壤盐分的生态适应性,本文基于田间定位观测,运用非线性最小二乘数值逼近法建立玉米耐盐函数模型;同时根据耐盐性分析,提出玉米在该灌区不同生态适宜区的划分标准。结果表明,盐碱地地膜覆盖在生产上有较好的控盐效果,可以使玉米苗期0～10、0～20和0～40cm土壤盐分分别降低61.2%、53.8%、41.3%,能够增强玉米对盐碱地的生态适应性;分段式耐盐函数模型和S型耐盐函数模型均能较好地反应玉米相对产量对浅层土壤盐分变化的响应关系;浅层0～40cm土壤盐分作为玉米根层盐分来分析玉米的耐盐性最具代表性,其对应中玉9号玉米的耐盐指数为6.583;根据耐盐性分析,将区域耕地划分为玉米最适宜区、适宜区、次适宜区和不适宜区,对应玉米苗期0～20cm膜外土壤盐分分别为低于1.178、1.178～2.036、2.036～3.465和高于3.465g/kg。本研究将为当地玉米种植合理布局、高效生产提供理论指导。     

The influence of high salt stress on starch,sucrose and degradative enzymes of two glycine max varieties that differ in salt tolerance

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.     

Significance of salt transport patterns in rice varieties differing in salt tolerance

Abstract

The absorption mechanisms for Na, K, SO₄ and Cl were tested in a salt tolerant (PVR 1) and a salt sensitive (GEB 24) rice varieties. The salt tolerant variety accumulated significantly larger amounts of Na than the salt sensitive variety. Further, PVR 1 absorbed SO₄ from Na₂SO₄ in preference to that from K₂SO₄. The absorption patterns for K and Cl were similar in both the varieties. It is concluded that the capacity of plant species to accumulate greater amounts of Na is a reflection of their halophytic feature.     

Impacts of different water salinity levels on salt tolerance,water use,yield, and growth of chives (Allium schoenoprasum)

ABSTRACT

Using saline irrigation water for crop production continues to gain more importance year by year, especially in regions where freshwater resources are very scarce. Therefore, this study was carried out to investigate the effects of six water salinity levels (0.38 (control), 1.0, 2.0, 4.0, 6.0, and 8.0 dSm^?1) on salt tolerance, evapotranspiration, and yield of chives under a rain shelter. The experiment was laid out in pots using a randomized plot design with four replicates of each treatment. Leaf fresh-dry weights, plant height, evapotranspiration, and water use efficiencies of chive plants were significantly affected by increasing levels of salinity. The results revealed that chives can be classified as a salt-sensitive crop with a threshold value of 1.13 dSm^?1 and relative yield decreased by 6.19% per unit increase of soil salinity. In conclusion, with appropriate leaching management practices, irrigation water with 0.38 dSm^?1 salinity level is recommended for chives production.     

The influence of salinity on the vegetative growth,osmolytes and chloride concentration of four halophytic species

The aim of this work was to study the influence of salinity of the fertigation solution on the vegetative growth, as well as on the osmolytes and chloride concentration of four halophytic species. Results show that the increase of salinity caused the reduction of plant fresh and dry matter in Asteriscus maritimus, while plant dry weight was unaffected by the salinity in Crithmum maritimum, Halimione. portulacoides and Limonium cossonianum. Salinity enhanced root growth of H. portulacoides. Salt-induced succulence was detected in A. maritimus. The translocation of Cl^– to the leaves is an important factor responsible for salt tolerance of A. maritimus and H. portulacoides. However, C. maritimum and L. cossonianum restricted the uptake of Cl^– and excrete salts through the leaves. Crithmum maritimum and H. portulacoides accumulated proline and soluble sugars in leaves which acts as osmoprotectant. Among the species studied, H. portulacoides has the greatest Cl^– phytoextraction efficiency.     

Variability for salt tolerance during germination in Lolium multiflorum Lam. naturalized in the pampean grasslands

Forage production is reduced in saline environments in the pampean grasslands, so search for tolerant germplasm is needed. Seed from 56 naturalized populations of Italian ryegrass (Lolium multiflorumLam.) was collected from grasslands of different agro-climatic districts of the Buenos Aires province (Argentina). These populations and three cultivars were screened for germination under saline conditions and to establish population affinities associated with the germination behaviour. A germination trial was conducted utilizing NaCl solutions with electrical conductivities of 0; 2 and 6 dSm-1. The interaction between entries and NaCl levels was not significant but there were differences among entries for all the characters analyzed. Only the mortality and the germination index were not affected by the increasing conductivity of the incubation media. The 'genetic determination grade' and relative performance of entries for the variables vigour, standard germination and dormancy also were calculated. Cluster analysis was performed and four groups were defined according to the germination behaviour of the accessions under the different NaCl levels. Using the germination traits analyzed, we detected variability in the naturalized populations of Italian ryegrass for salt tolerance.     

不同类型植物耐盐特性对脱硫废弃物的响应及其耐盐指数综合评价

为探讨施用脱硫废弃物对生长在盐土和碱土上的不同植物耐盐特性的影响,并建立综合评价指标体系,对不同植物的耐盐指数进行综合评价。本试验在2008—2010年期间,分别在碱土区和盐土区2个试点,以施与不施脱硫废弃物为主处理,选用9种不同耐盐植物为副处理开展了田间裂区试验,观测分析了各耐盐植物的出苗特征、生长生理特征、产量等指标及土壤盐分、养分、碱化度(ESP)等性质,从而建立包括植物生长、生理指标、土壤指标和经济指标的综合评价指标体系,并应用TOPSIS法对不同耐盐植物的耐盐指数进行综合评价。结果表明:与CK相比,施用脱硫废弃物能显著改善各耐盐植物的生长发育,提高出苗率、相对生长速率(株高)和相对生物量,增加自由水和束缚水的比值(F/B),且在碱土上效果优于盐土。不同类型耐盐植物之间差异显著,表现出各自的耐盐、碱特性。同时施用脱硫废弃物种植耐盐植物可提高土壤有机质增加速率和全盐、碱化度的降低速率。同样地,对盐碱土的改良效果表现为碱土优于盐土,不同耐盐植物之间差异显著。通过综合评价把不同耐盐植物分为强、较强、中和弱4个耐盐等级。与CK相比,施用脱硫废弃物可提高耐盐植物的耐盐等级,扩展耐盐植物在盐碱地上的种植范围。由此可知,耐盐植物的耐盐特性受植物类型、盐碱地类型、改良措施等因素影响。因此,从生态经济的角度寻求合理的综合评价方法来确定耐盐植物的耐盐特性具有重要科学意义,可为进一步优化盐碱地生态修复模式提供理论支持。     

Mineral ion composition of halophytes and associated soils in Western Canada

Abstract

The mineral ion contents of seven halophytic species in the family Chenopodiaceae, and associated soils were examined. Each species was found growing in soils with wide ranges of salinity, sodicity and salt ion composition. Absolute concentrations of Na, Ca, Mg, K, Cl and SO₄ in shoot tissue differed significantly among species. Species were classified into two groups: (1) chloride halophytes, with ion composition dominated by Na and Cl (Atriplex patula, Chenopodium rubrum, Salicornia rubra and Suaeda depressa), and (2) alkali halophytes, with relatively high K, Mg, Ca and low Cl contents (Chenopodium salinum, Kochia scoparia and Salsola pestifer). All species accumulated ? and excluded SO₄, relative to concentrations of these ions in soil. Salsola pestifer was unique in strongly excluding Na.     

Growth,Water Status,and Nutrient Accumulation of Seedlings of Tamarindus indica Linn. in Response to Soil Salinity

Greenhouse experiments in a completely randomized block design were conducted to assess the effect of soil salinity on emergence, growth, water status, proline content, and mineral accumulation of seedlings of Tamarindus indica Linn. (Caesalpiniaceae). Sodium chloride (NaCl) was added to the soil, and the salinity was maintained at 0.2, 3.9, 6.2, 8.1, 10.0, 11.9, and 13.9 dS m^?1. Salinity lowered water content and water potential of tissues, which resulted in an internal water deficit to plants. Consequently, seedling growth significantly decreased and proline content in tissues increased as salinity increased. There were no effective mechanisms to control net uptake of sodium (Na⁺) and its transport to shoot. Potassium (K) and calcium (Ca) contents in tissues significantly decreased, while nitrogen (N) content significantly increased as salinity increased. Changes in tissues and whole-plant accumulation patterns of other nutrients, as well as possible mechanisms for avoidance of Na⁺ toxicity in this species in response to salinity, are discussed.     

Assessment of variability in salt tolerance based on seedling growth in Triticum durum Desf.

Variability in response to salinity was examined in 29 Triticum durum Desf. accessions or cultivars based upon relative root and shoot lengths of 14-day-old seedlings grown in control and 100 mM NaCl solutions. NaCl caused a significant reduction of root and shoot growth for all accessions/cultivars, but the degree of reduction differed between them. Some cultivars had significantly greater relative root and shoot lengths than others, suggesting that there may be potentially useful variability in salinity tolerance within the durum wheats.     

The ion uptake mechanism of allophane

Rather greater variations in the cation exchange capacity (CEC) value of Allophane, say, 20 to 100 me per 100 g of clay (1), have been reported by a number of investigators. BIRRELL and his collaborators (5, 6) revealed that the CEC of allophane depends on concentration and pH of a leaching solution, kinds of cation and anion, volume of washing alcohol, and its water content. The results suggest the peculiarity of allophane in ion-exchange phenomena.     

紫花苜蓿幼苗耐盐性的近红外光谱鉴定

紫花苜蓿幼苗耐盐性快速鉴定对于耐盐种质资源筛选和耐盐新品种选育具有重要意义。脯氨酸和丙二醛是表征植物耐盐性的两种重要生化指标。研究应用便携式近红外仪和近红外光谱分析技术,结合偏最小二乘回归法,研究了40个不同紫花苜蓿品种幼苗耐盐性的脯氨酸和丙二醛含量,建立了新鲜样品和干燥样品的近红外漫反射光谱定量分析模型。研究结果表明：脯氨酸、丙二醛的近红外漫反射光谱分析效果均较好,校正模型决定系数R2 和验证集样品预测值与常规分析测定值的验证决定系数r2都大于0.85,两种样品脯氨酸的相对分析误差RPD值分别为1.72     

Yield and protein content of barley as affected by release rate of coated urea and rate of nitrogen application

Coated urea consists of a urea core and a polymer coating. It meters out urea over a period of time. In the market place, price is favorable for high protein content feed barley. The objectives of this study were to determine release rate of urea from coated urea products and relative effectiveness of urea, coated urea or a mixture of coated urea products with different release rates in increasing yield and protein content of barley. Release rate of coated urea Mini I (quick release) and Mini II (slow release) in water was determined at 23°C by recovering ten pre‐weighed granules from 500 mL water at 6 h, 2, 4, 6, 8, 10, and 12 days. The recovered granules were dried and then weighed. Barley (Hordium vulgare L. cv. Duke) was grown in potted soil (2 L) at 15°C for 90 days in a growth chamber with treatments of Nil, non‐coated urea, Mini I, Mini II, Mixture I (1/3 urea+1/3 Mini I+1/3 Mini II) and Mixture II (1/5 urea+2/ 5 Mini I+2/5 Mini II). The nitrogen (N) application rates were 100, 200 and 300 kg N ha^‐1. Above‐ground plant samples were taken at 22, 44, 66, and 90 (maturity) days after seeding, and dry matter mass per pot and N content of the plant samples were determined. The release of urea from Mini I and Mini II followed a lognomial pattern. Increasing N application rate increased dry matter yield of barley. Dry matter yield from urea tended to be higher than other treatments at each rate of N application, but that did not couple with high grain protein content. At 100 kg N ha^‐1, there was no post anthesis N assimilation (PANA) for urea and Mini I, but there were 4, 14, and 13% PANA for Mini II, Mixture I, and Mixture II, respectively. However, when N application rate was increased to 200 and 300 kg N ha^‐1, there was PANA even for urea treatment. Protein content of barley grain was higher with coated urea or mixture treatments than with urea at each rate of N application. The potential N loss (i.e., difference between percentN released from fertilizers and percent fertilizer N recovered by barley) was Mini II<Mini I<Mixture II<Mixture I for the same N application rate, and was 100<200<300 kg N ha^‐1 for the same fertilizer treatment. In conclusion, at a limited N application rate, coated urea with a slow release rate or a combination of two coated urea products (quick and slow release) with urea increased grain protein content of barley. The potential N loss was less with coated urea applied alone than with a mixture of coated urea and urea.     

两种盐生植物在南北疆地区的适生性及吸盐能力

为了摸清盐生植物在南北疆改良盐碱地的实际应用效果,更好地利用盐碱植物,在南北疆地区进行田间试验,研究了两种盐生植物在新疆南北疆盐碱地的适应性及吸盐能力。结果表明,盐生植物在南疆的成活率明显高于北疆;而盐地碱蓬成活率明显要高于海篷子;北疆种植的盐生植物其植物体内的总含盐量明显高于南疆种植的盐生植物,其中盐地碱蓬高出约55%,海篷子高出约46%。由此可以看出,盐地碱蓬和海篷子更适合于南疆地区生长,而在北疆环境两种盐生植物吸盐能力均强于南疆环境,海蓬子吸盐能力明显强于盐地碱蓬。