盐胁迫下丛枝菌根真菌对玉米水分和养分状况的影响

在ＮａＣｌ胁迫下无论接种ＡＭ真菌与否玉米植株生物产量均减少,但不接种处理的减少幅度比较种处理的高１０个百分点左右,盐胁迫下接种ＡＭ真菌的玉米根系和地上部的干重、叶片水热均高于不接种处理、叶片脯氨酸含量低于不接种处理,在盐胁迫下真菌菌丝对玉米植株营养的贡献由４５．３％降为４２．６％,ＡＭ真菌对植株生长的效应反而由３０．９％提高到６３．５％,说明ＡＭ真菌主米耐盐性的机理与改善植株的水分状况和Ｐ营养状况     

盐度和CO2倍增环境下碱蓬幼苗呼吸酶活性的变化

研究了生长在正常大气ＣＯ２和ＣＯ２倍增环境中的盐生植物碱蓬（Ｓｕａｅｄａｓａｌｓａ）幼苗呼吸酶活性对ＫＣｌ和ＮａＣｌ的反应．结果表明,在ＣＯ２倍增（７００μｌ·Ｌ－１）和正常大气ＣＯ２（３５０μｌ·Ｌ－１）下,３００ｍｍｏｌ·Ｌ－１ＫＣｌ和ＮａＣｌ均能抑制琥珀酸脱氢酶（ＳＤＨ）和苹果酸脱氢酶（ＭＤＨ）活性,而异柠檬酸脱氢酶（ＩＤＨ）活性为ＮａＣｌ抑制、ＫＣｌ促进;ＮａＣｌ和ＫＣｌ明显抑制细胞色素氧化酶（ＣＯ）和光呼吸中乙醇酸氧化酶（ＧＯ）、羟基丙酮酸还原酶（ＨＰＲ）活性;并指出在ＫＣｌ胁迫下,ＣＯ２使三羧酸循环（ＴＣＡＣ）的运行变慢,ＮａＣｌ胁迫下使其加快,ＴＣＡＣ运行限速步骤与ＭＤＨ无关,ＣＯ为盐对呼吸代谢影响的重要位点．另外,Ｋ＋、Ｎａ＋对蛋白表达的影响有差异,ＣＯ２可使盐胁迫下的碱蓬幼苗蛋白表达降低．     

亚硒酸钠对四氯化碳损伤草鱼肝原代细胞与肝组织的保护作用

不同浓度四氯化碳（ＣＣｌ４）对草鱼肝原代细胞的损伤实验中,ＣＣｌ４浓度为１０μｌ／ｍｌ可引起细胞血清中丙氨酸氨基转移酶（ＡＬＴ）、天门冬氨酸氨基转移酶（ＡＳＴ）、乳酸脱氢酶（ＬＤＨ）逸出量与细胞破损率显著增高,培养液中添加亚硒酸钠（Ｎａ２ＳｅＯ３）０．２μｇ／ｍｌ,则可降低ＡＬＴ、ＡＳＴ、ＬＤＨ的逸出量,减轻细胞破损程度。Ｎａ２ＳｅＯ３保护实验中,Ｎａ２ＳｅＯ２＋ＣＣｌ４组预先腹腔注射（ｉｐ）０．１ｍｇ／ｋｇ．ｂｗ连续三日,末次ｉｐＣＣｌ４混合液１ｍｌ／ｋｇ．ｂｗ,２４ｈ内肝组织超氧物歧化酶（ＳＯＤ）相对活性比ＣＣｌ４组提高达９１．５％,第七日仍提高达５４．５％,与对照组的水平基本接近;血清中丙氨酸氨基转氨酶（ＡＬＴ）水平逐渐降低。本实验还观察到Ｎａ２ＳｅＯ３可引起肝脂质过氧化物显著降低,肝微粒体蛋白含量与细胞色素Ｐ—４５０活性升高;组织切片观察显示肝组织损伤程度减轻,７２ｈ后细胞核增多。表明Ｎａ２ＳｅＯ３可提高草鱼肝清除自由基能力,增强肝脏解毒功能。     

红豆草耐盐愈伤组织的筛选及植株再生

将红豆草种子在含１．２％ＮａＣｌ的ＭＳ培养基上萌发以消除盐敏感的幼苗,把存活的幼苗下胚轴切段在含１ｍｇ／Ｌ２,４－Ｄ、０．５ｍｇ／Ｌ６－ＢＡ及１．２％ＮａＣｌ的ＭＳ培养基上诱导愈伤组织,通过连续筛选得到可耐受１．８％ＮａＣｌ的愈伤组织,在有０．２ｍｇ／Ｌ ＮＡＡ和１ｍｇ／Ｌ ＩＡＡ存在下该愈伤组织分化出芽,待幼,待幼苗长至３ｃｍ左右时转至含２ｍｇ／ＬＮＡＡ和或ＩＢＡ的１／２ＭＳ培养基上生根。对对照     

NaCl胁迫对螺旋藻生长及抗氧化酶活性的影响

在０１％～５．０％ＮａＣｌ浓度范围的培养基中培养极大螺旋藻（Ｓｐｉｒｕｌｉｎａｍａｘｉｍａ）,发现ＮａＣｌ浓度高于２．０％时螺旋藻生长受到明显抑制。培养７天后测定超氧化物歧化酶（ＳＯＤ）、抗坏血酸过氧化物酶（ＡＳＡＰＯＤ）、过氧化氢酶（ＣＡＴ）活性和丙二醛（ＭＤＡ）含量。结果表明：在盐胁迫下,ＳＯＤ酶活性升高;抗坏血酸过氧化物酶和过氧化氢酶活性在低盐胁迫下活性升高,高盐胁迫下抗坏血酸过氧化物酶活性迅速降低,过氧化物酶则完全失活;ＭＤＡ含量先随盐胁迫程度增加而降低,后随盐胁迫的进一步增强恢复至对照水平。     

不同种子预处理方法对提高三树种幼苗耐盐性的效应

刺槐（ＲｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａＬｉｎｎ．）、湿地松（ＰｉｎｕｓｅｌｉｏｔｉＥｎｇｅｌｍ．）和侧柏〔Ｐｌａｔｙｃｌａｄｕｓｏｒｉｅｎｔａｌｉｓ（Ｌ．）Ｆｒａｎｃｏ〕种子经０３％ＣａＣｌ２,２５０μｇ／ｇＨ３ＢＯ３和２５０μｇ／ｇ多效唑（ＭＥＴ）浸种２４ｈ,然后测定幼苗的耐盐性。结果表明,在０．３％ＮａＣｌ胁迫条件下,不同种子预处理方法对种子发芽率、平均苗高、根茎比、简易活力指数（ＳＶＩＳ）以及幼苗中Ｎａ＋与Ｋ＋的累积量、Ｎａ＋／Ｋ＋比及游离脯氨酸含量有较大影响。树种不同,处理效果也存在明显差异。湿地松以０．３％ＣａＣｌ２,侧柏以２５０μｇ／ｇＨ３ＢＯ３浸种处理效果最好,显著提高种子发芽率、平均苗高、根茎比和ＳＶＩＳ,降低幼苗Ｎａ＋吸收量和Ｎａ＋／Ｋ＋比,缓解盐胁迫逆境。３种种子预处理方法均降低刺槐种子发芽率、平均苗长和ＳＶＩＳ,但提高刺槐幼苗游离脯氨酸含量和幼苗根茎比,减少幼苗对Ｎａ＋的吸收,降低Ｎａ＋／Ｋ＋比     

NaCl胁迫番茄苗的生长和营养元素积累（简报）

在ＮａＣｌ胁迫下番茄植株生长速率和营养元素积累均下降,但两品种的花冠比没有改变。不同品种番茄植株的生长和根冠部元素的积累对ＮａＣｌ胁迫的响应在异。１００ｍｏｌ·Ｌ＾－１ＮａＣｌ处理下,Ｋ＾＋积累与植株生长速率呈显著正相关,Ｃａ＾２＋、Ｍｇ＾２＋的积累与生长速率相关性不显著。     

CO2倍增环境生长的小麦幼苗对盐胁迫的生理反应

研究了ＣＯ２倍增／盐胁迫对不同抗盐性冬小麦幼苗有机干重,Ｋ＾＋,Ｎａ＾＋,Ｃａ＾＋＋,Ｍｇ＾＋＋含量,脯氨酸水平及蛋白质变化的效应,表明两种小麦生长在１５０ｍｍｏｌ／ＬＮａＣｌ下,其有机干重,Ｋ＾＋,Ｃａ＾＋＋,Ｍｇ＾＋＋含量下降,而Ｎａ＾＋明显长高;ＣＯ２倍增可增加小麦有机干重,使一价阳离子Ｋ＾＋,Ｎａ＾＋含量升高,二价阳离子Ｃａ＾＋＋,Ｍｇ＾＋＋呈下降趋势,同时有利于游离脯氨酸的积累,并为植物     

钙在无花果细胞盐诱导脯氨酸积累中的作用

接种于含ＮａＣｌ 培养基的无花果愈伤组织细胞生长极显著受抑,Ｎａ＋ 含量增加,Ｋ／Ｎａ 比值下降,游离脯氨酸积累。培养基中添加一定量ＣａＣｌ２ 不仅在一定程度上缓解盐分对生长的抑制作用,增加Ｋ＋／Ｎａ ＋ 比,而且明显促进游离脯氨酸积累。如果在添加钙的同时再添加细胞钙调素活性抑制剂盐酸氯丙嗪（ＣＰＺ） 或盐酸三氟拉嗪（ＴＦＰ） ,均使钙促进的脯氨酸积累受到明显抑制,表明盐胁迫诱导的脯氨酸积累可能涉及细胞ＣａＣａＭ系统。     

新疆呼图壁绿洲外缘的盐节木（Halocnemum strobilaceum）及其群落的生物生态学特征

盐节木株丛矮小,高约２０－４０ｃｍ;５月底至８月底净生长高度约３ｃｍ。侧根发达,主要分布在土壤由表层往下水分含量急增、多数情况下盐分逐步降低的２０－４０ｃｍ的土层内,几乎与地表平行伸展,有的长达３ｍ以上。盐节木群落为多汁盐柴类半灌木荒漠中的一个群系。本区记载有８个群丛,分布在地下水位１．０－１．７ｍ、表土层含盐量为４％－８％的盐土上。种类组成贫乏,群落结构简单,总覆盖度３０％－５０％,生物量１０００－２０００ｋｇ／ｈｍ￣２。群落中盐节木、有叶盐爪爪（Ｋａｌｉｄｉｕｍｆｏｌｉａｔｕｍ）具有很高的Ｎａ、Ｓ含量,分别在５００００ｍｇ／ｋｇ、１００００ｍｇ／ｋｇ以上;Ｎａ／Ｋ、Ｎａ／Ｃａ、Ｓ／Ｐ比值为８．５－２６．０,其它植物为１左右;植物中的Ｃａ／Ｍｇ比值为１．０－１．６。盐节木６种元素含量的季节变化,Ｎａ呈增高趋势;其变化曲线与Ｃａ、Ｍｇ相反;Ｎａ、Ｓ曲线相似。盐节木水提取液中具有高的Ｃｌ￣－、含量,ｐＨ为６．６６－６．８４。盐节木群落广泛分布在绿洲外缘的盐碱地上。在盐碱地改良、防止风沙、保护绿洲、牲畜冬春放牧等方面,具有重要的生态经济意义。     

Growth of corn in saline waters

Eight cultivars of Zea mays plus the wild species Zea diploperennis were screened for seedling saline tolerance up to 3.2% NaCl. The best performances were given by the cultivars Mo 17 and commercial Hawaiian Super Sweet Hybrid. These two were then field grown on coral-cinder beds using drip irrigation with fresh of half-strength sea water (1.5–1.7% dissolved solids). Growth and chemical data for Mo 17 at 12 weeks show reduced growth but the same percentage dry matter. Ash, protein and total sulfur were higher in saline plants, silica and total phosphorus lower. Na, K. Mg, and Cl were elevated and Ca reduced slightly. Fe was also increased in saline plants. Both Mo 17 and Super Sweet Hybrid corn flowered and produced seed which retained essentially normal viability both in fresh and salt water.     

Effects of residual soil salinity resulting from irrigation with sulphate waters on lettuce

Summary The response of lettuce (Lactuca sativa L.) to residual soil salinity as influenced by the ionic composition of two different saline waters (EC_w=3.1 dS/m, referenced at 25°C) and rain water, was investigated in a greenhouse experiment with three successive plantings of lettuce in the same soil. One of the saline waters was saturated with gypsum (SO₄=35 mol (−)m⁻³) and the other contained SO₄ at 15 mol (−)m⁻³ and Na and Cl at 18 and 14 mol (±)m⁻³, respectively (mixed water). All waters were applied with a 0.3 leaching fraction. Soil water salinity and sodium adsorption ratio (SAR) increased in both cases using saline waters. The effect of mixed saline water was higher and became more marked after each planting, resulting from higher contribution of Na and Cl to soil salinity. With both saline waters, soil solution became saturated with gypsum. At first planting, gypsum saturated and mixed waters produced fresh yield increases of 15 and 24%, respectively, relative to rain water. At second planting, however, there was reduction in yield of 11 and 22%, respectively, relative to rain water; at third planting yield reduced by 22 and 76% with gypsum saturated and mixed water, respectively.     

The influence of salinity on the cercariae of three species of Schistosoma

Donnelly F. A., Appleton C. C. and Schutte C. H. J. 1984. The influence of salinity on the cercariae of three species of Schistosoma. International Journal for Parasitology14: 13–21. The effect of salinity on the longevity and infectivity of cercariae of Schistosoma mattheei, Schistosoma haematobium and Schistosoma mansoni was determined. No significant differences in cercarial longevity occurred (p > 0.05) in low salinities (0–5.25%), whereas further increases in salinity resulted in progressive decreases in survival. In salinities ? 17.5%, cercariae were incapable of surviving for longer than 11 min. A maximum life-span of up to 122 h was recorded for some S. mattheei cercariae. Cercarial infectivity, as indicated by worm returns, was reduced progressively with increasing salinity up to a lethal limit of 10.5%. Differences in the salinity tolerance of the cercariae of the three species were discussed.     

Vegetation indicators of salinity in northern Queensland

Abstract The possibility that plants could serve as indicators of underlying soil salinity in northern Queensland, Australia, was investigated using 2197 site observations recorded during a land resources inventory of the Dalrymple Shire. The area surveyed intersects three biogeographical regions: the desert uplands, the Einasleigh uplands and the northern brigalow belt. The three dominant plant species in the lower, middle, and upper vegetation strata were recorded, along with laboratory measurements of electrical conductivity down each soil profile. Correspondence analysis, generalized additive models and clustering were used to investigate the relationship between plant occurrence, climatic and edaphic factors. The results of these statistical analyses strongly suggest a relationship between salinity and brigalow plant communities. A generalized additive model to predict soil salinity from environmental variables including vegetation data is presented.     

Phytoextraction and Accumulation of Boron and Selenium by Poplar (Populus) Hybrid Clones

There has been much interest recently in central California for reusing drainage water to grow trees. A sand-culture study was conducted to investigate the accumulation of boron (B) and selenium (Se) in eight hybrid poplar (Populus) clones irrigated with synthetic agricultural effluent containing increasing levels of chloride salt, B, and Se. Electrical conductivity (EC) ranged from 1.5 to 15 dS m^-1, B levels from 1 to 5 mg L^-1, and Se levels from 100 to 500 μg L^-1. Compared with all tree organs, the leaves accumulated the greatest concentrations of B and Se at the time of harvest. The results show that pooled leaf B concentrations were positively correlated with EC levels (r = 0.78, P < 0.001) and negatively correlated (r = -0.53, P < 0.001) with leaf dry matter for all clones at all tested B levels. Combined leaf and stem Se data show, respectively, a significant decrease (P < 0.05 level) in tissue accumulation of Se with increased salinity. Toxicity symptoms (e.g., burning leaf margins, shoot die back) occurred in most clones grown at 12 and 15 dS m^-1 treatments leading to leaf abscission. Based on the data, clone 49177 (Populus trichocarpa × P. deltoidus) best tolerated the tested parameters among the clones and accumulated the greatest amount of B and Se. The moderate ability of the Populus species to remove and accumulate B and Se from saline effluent is most effective at salinity levels less than 7 dS m^-1.     

花生品种耐盐性指标筛选与综合评价

采用盆栽试验,设置不同盐胁迫浓度,通过萌发至幼苗期的出苗速度、植株形态和生物量等指标对200个花生品种(系)进行耐盐性评价.结果表明: 随盐胁迫浓度的增加,花生出苗时间延长,对植株形态建成抑制加重,物质积累减少.鉴定花生品种耐盐性强弱的适宜盐胁迫浓度为0.30%~0.45%.采用隶属函数值法将10个指标归结为平均隶属函数值,根据不同胁迫浓度下各指标与平均隶属函数值之间的相关性大小,植株鲜质量、地上部鲜质量、地下部鲜质量、地下部干质量、株高和主茎高均较大,可作为首选指标,植株干质量、地上部干质量、主根长和出苗速率均较小,可作为辅助指标综合判断品种的耐盐能力.200个品种(系)在不同盐胁迫浓度下均可分成高度耐盐型、耐盐型、盐敏感型和高度盐敏感型4组.随盐胁迫强度加大,耐盐品种数量下降,而盐敏感品种数量上升.部分品种在低、中、高盐胁迫强度下表现出统一性(均耐盐或均敏感);部分品种存在差异性,即低胁迫强度下表现耐盐性而在高胁迫强度下表现盐敏感性.     

Root-zone constraints and plant-based solutions for dryland salinity

Limitations to agricultural productivity imposed by the root-zone constraints in Australian dryland soils are severe and need redemption to improve the yields of grain crops and thereby meet world demand. Physical, chemical and biological constraints in soil horizons impose a stress on the plant and restrict plant growth and development. Hardsetting, crusting, compaction, salinity, sodicity, acidity, alkalinity, nutrient deficiencies and toxicities due to boron, carbonates and aluminium are the major factors that cause these constraints. Further, subsoils in agricultural regions in Australia have very low organic matter and biological activity. Dryland salinity is currently given wide attention in the public debate and government policies in Australia, but they only focus on salinity induced by shallow groundwater. However, the occurrence of transient salinity in root-zone layers in the regions where water tables are deep is an important issue with potential for larger economic loss than water table-induced seepage salinity. Root-zone constraints pose a challenge for salinity mitigation in recharge as well as discharge zones. In recharge zones, reduced water movement in sodic horizons results in salt accumulation in the root zone resulting in chemical and physical constraints that reduce transpiration that, in turn, upsets salt balance and plant growth. High salinity in soil and groundwater restricts the ability of plants to reduce water table in discharge zones. Thus plant-based strategies must address different kinds of limitations in soil profiles, both in recharge and discharge zones. In this paper we give an overview of plant response to root-zone constraints but with an emphasis on the processes of salt accumulation in the root-zone of soils. We also examine physical and chemical methods to overcome subsoil limitations, the ability of plants to adapt to and ameliorate these constraints, soil modification by management of agricultural and forestry ecosystems, the use of biological activity, and plant breeding for resistance to the soil constraints. We emphasise that soil scientists in cooperation with agronomists and plant breeders should design site-specific strategies to overcome multiple soil constraints, with vertical and lateral variations, and to develop plant-based solutions for dryland salinity.     

Interaction of endogenous and exogenous factors controlling locomotor activity rhythms in Carcinus exposed to tidal salinity cycles

The shore crab Carcinus maenas (L.) reported hitherto not to express endogenous circatidal rhythmicity in winter, is shown not to lose the ability to express such rhythmicity. Crabs maintained in constant reduced salinity in winter exhibit circatidal and circadian rhythms similar to the normal endogenous rhythms of summer caught crabs.In sinusoidal changes of salinity of tidal periodicity, reductions of salinity and increases to ambient sea water induced increased locomotor activity. The former were purely exogenous responses but the latter were also observed to entrain the underlying endogenously controlled circatidal pattern of behaviour.The occurrence of separate exogenous and endogenous responses to different phases of imposed salinity cycles has implications when seeking to understand rhythmic locomotor activity of crabs on the shore and in the search for components of the underlying physiological clock mechanism.     

Response of Halomonas campisalis to saline stress: changes in growth kinetics, compatible solute production and membrane phospholipid fatty acid composition

The haloalkaliphile Halomonas campisalis, isolated near Soap Lake, Washington, was grown under both aerobic and denitrifying conditions from 0 to 260 g L(-1) NaCl, with optimal growth occurring at 20 and 30 g L(-1) NaCl, respectively. Halomonas campisalis was observed to produce high concentrations of compatible solutes, most notably ectoine (up to 500 mM within the cytoplasm), but hydroxyectoine and glycine betaine were also detected. The types and amounts of compatible solutes produced depended on salinity and specific growth rate, as well as on the terminal electron acceptor available (O(2) or NO(3) (-)). A decrease in ectoine production was observed with NO(3) (-) as compared with O(2) as the terminal electron acceptor. In addition, changes in the phospholipid fatty acid composition were measured with changing salinity. An increase in trans fatty acids was observed in the absence of salinity, and may be a response to membrane instability. Cyclic fatty acids were also observed to increase, both in the absence of salinity, and at very high salinities, indicating cell stress at these conditions.     

Salinization of the soil solution decreases the further accumulation of salt in the root zone of the halophyte Atriplex nummularia Lindl. growing above shallow saline groundwater

Water use by plants in landscapes with shallow saline groundwater may lead to the accumulation of salt in the root zone. We examined the accumulation of Na⁺ and Cl^? around the roots of the halophyte Atriplex nummularia Lindl. and the impacts of this increasing salinity for stomatal conductance, water use and growth. Plants were grown in columns filled with a sand–clay mixture and connected at the bottom to reservoirs containing 20, 200 or 400 mM NaCl. At 21 d, Na⁺ and Cl^? concentrations in the soil solution were affected by the salinity of the groundwater, height above the water table and the root fresh mass density at various soil depths (P  < 0.001). However, by day 35, the groundwater salinity and height above the water table remained significant factors, but the root fresh mass density was no longer significant. Regression of data from the 200 and 400 mM NaCl treatments showed that the rate of Na⁺ accumulation in the soil increased until the Na⁺ concentration reached ~250 mM within the root zone; subsequent decreases in accumulation were associated with decreases in stomatal conductance. Salinization of the soil solution therefore had a feedback effect on further salinization within the root zone.