海涂区不同植被类型下土壤盐渍剖面及其电磁感应响应特征

针对滨海滩涂区植被类型与土壤盐渍化间的内在联系,以黄河三角洲典型海涂区为研究对象,结合电磁感应仪EM38与田间采样,分析了不同植被类型下土壤盐渍剖面分布特征,并对各植被类型下土壤盐渍剖面的电磁感应响应特征进行了比较.结果表明：研究区土壤盐分具有较强的表聚性与变异强度,水平磁感式表观电导率(EM_h)对浅层土壤盐分响应较好,而垂直磁感式表观电导率(EM_v)对深层土壤盐分的响应优于EM_h;土壤盐渍剖面分为表聚型、底聚型和平均型3类,表聚型盐渍剖面主要为光板地和盐蒿地,底聚型的地表植被以棉花为主,平均型主要为杂草,且土壤盐分表聚强度为光板地>盐蒿地>杂草地>棉花地;随着植被类型由棉花—杂草—盐蒿—光板地变化,各剖面的EM_v/EM_h值逐渐降低.经非参数检验,植被类型与电磁感应响应特征具有显著相关性,且不同植被类型的EM_v/EM_h分布特征差异明显.     

新疆典型盐生植物营养器官盐分积累与生态化学计量特征

对盐生植物体内器官盐分积累和碳(C)、氮(N)、磷(P)化学计量特征的研究, 有助于了解盐生植物养分、盐分的分配机制和其对盐渍环境的适应策略。该文选择新疆4种典型的真盐生植物(3种灌木植物: 盐节木(Halocnemum strobilaceum)、小叶碱蓬(Suaeda microphylla)、盐爪爪(Kalidium foliatum), 1种草本植物: 盐角草(Salicornia europaea)为研究对象, 对比研究了它们的根、茎、叶中的盐分积累和C、N、P化学计量特征以及二者间的相关性。结果显示: 1)在生长旺盛期, 4种盐生植物体内盐分积累可形成“盐岛”效应(Na⁺、Cl^-和电导率随盐离子从植物根部向顶端运输过程呈显著增加的趋势)。2) 4种盐生植物中灌木群落的生长主要受到P的限制; 草本群落的生长受N和P (偏P)共同限制。3)器官、物种和二者的交互作用均能影响盐生植物的盐分(除Mg²⁺外)特征和C、N、P生态化学计量特征。4) 4种盐生植物C与N、P之间显著负相关, N与P之间显著正相关。5)盐生植物体内总盐分、Na⁺和K⁺与N、N:P之间呈显著正相关关系, 与C、C:N、C:P之间呈显著负相关关系, 而K⁺和CO₃^2-与P之间却显著正相关。盐生植物体内盐分和养分在应对盐渍环境上存在一定的相互促进关系, 增施N肥有助于盐生植物对氯化物盐渍土的脱盐。这些发现为了解盐渍生境中盐生植物的生理生态适应及盐渍土的改良提供一定的理论依据。     

花花柴脱盐能力及脱盐结构研究

通过定位测试和电镜观察等方法,研究了花花柴的脱盐能力及脱盐结构,证实花花柴有极强的脱盐能力。生长第一年能使土壤全盐降低52％～56％,第二年降低80％左右,使0～40cm土壤含盐量降到1％以下,基本达到复耕水平。其脱盐机理与它结构上有泌盐腺、泌盐孔、特殊的表皮收集细胞和活跃的离子跨膜运输等密切相关。可以认为,花花柴是改良内陆盐渍环境优良的先锋植物。     

几种典型盐地植物显微和亚显微结构的研究

典型盐地植物解剖和形态的特征,通常可以看作是对盐度的适应。故研究特定地区典型盐地植物的解剖特征,是了解植物对盐渍的适应和盐渍对植物影响很重要的方面。为此我     

塔里木河下游柽柳ABA累积对地下水位和土壤盐分的响应

近年来发现在逆境下(干旱、低温、高温、盐渍等)的植物体内大量积累ABA,从而引导人们去研究ABA与植物抗逆性之间的关系。在塔里木河下游地区影响植被正常生长发育的各种胁迫因子中,地下水位和土壤盐分是导致"绿色走廊"衰败的主要因素。柽柳是塔里木河下游荒漠植被的主体,对于改善生态环境、遏制沙漠化、保护生物多样性等诸多方面具有重要作用。因此,研究柽柳和地下水位以及土壤盐分的关系,对于维护塔里木河流域天然植被赖以生存的环境,保护柽柳这一重要的生物资源,维持生态平衡的良性循环具有重要意义。运用国际通用软件SAS6.12对塔里木河下游柽柳ABA和地下水位以及土壤盐分进行相关分析表明,柽柳ABA含量与地下水位呈极显著正相关,相关系数R=0.80305(显著性程度P=0.0003);与土壤盐分呈显著负相关,相关系数R=-0.59036(显著性程度P=0.0205)。由各断面柽柳ABA含量变化与地下水位和土壤盐分关系分析结果可以初步推断:3.12m的地下水位和0.96g/L的土壤盐分已经威胁到柽柳的正常生长发育,地下水位超过5.59m、土壤盐分大于1.61g/L则会对柽柳造成严重胁迫。在恢复和保育塔里木河流域天然植被的过程中,应该把对植被造成胁迫的外界条件的成因和植被自身的抗旱、抗盐等抗逆特性结合起来进行考虑:根据耐旱耐盐植被的合理生态水(盐)位,在主河道两岸维持一定范围的地下水位,使乔木、灌木、草本植被能良好地生长,发挥多种生态功能,这样既可以避免水资源的浪费又能充分发挥生态输水的功效,有利于从根本上解决"绿色走廊"的问题。     

山东省农业科学院植物保护研究所简介

山东省农业科学院植物保护研究所建于1959年,隶属于山东省农业科学院,是社会公益类研究事业单位,主要从事植物病、虫、草害发生规律及防控技术研究与应用,设有植物病害、农药、微生物、生物技术、生物防治与昆虫5个研究室和“山东省农科院植物医院”、“山东省农科院植保所新农药中试厂”两个经济实体,建有“山东省植物病毒重点实验室”,是农药药效试验、农药生测试验、农药残留试验、生物防治产品、农业转基因生物环境安全检测和农业转基因产品检测的指定试验和检测单位。     

红树植物盐分含量及其调节

本文分析了海南岛东北部15种红树植物不同叶龄叶片水分与盐分含量,探讨了红树植物的盐分调节方式。结果初步表明:红树植物是高度聚盐生植物,其叶内水溶性盐离子浓度多倍于海水;随着叶片衰老,硫酸盐均发生显著积累,但氯化物、钠盐和钾盐依种不同而呈现积累、稳定或减少;在衰老过程中,叶片多汁性通常保持稳定。红树植物主要调盐方式包括根系拒盐、盐腺泌盐、叶片中的盐分转移和富盐老叶脱落。     

植物对盐分空间不均匀分布的形态和生理响应研究进展

盐胁迫是干旱、半干旱地区以及灌溉土地主要的非生物胁迫,是影响农业生产的主要不利环境因子之一。随集约化灌溉农业的发展、水资源的缺乏、气候干旱带来的蒸发量的增加,土壤及地下水盐渍化程度不断增加。自然界中,土壤盐分在时空上呈不均匀分布。关于植物对均匀盐胁迫的响应研究报到较多,然而植物对不均匀盐胁迫的响应研究报道较少。分析了国内外植物适应不均匀盐胁迫的研究案例,从植物地上部分生长、地下部分生长、水分调节、光合作用以及离子调控等方面阐述植物适应盐分不均匀分布的生理机制,并提出展望。     

植物内生真菌防治根结线虫研究进展

根结线虫病是对农作物危害严重且难以防治的病害，并随着我国设施农业的发展日趋严重。常规的化学防治方法因毒性大、破坏生态环境而不适应农业的可持续发展。作为一种能稳定寄生在作物体内的生物防治真菌，内生真菌通过抑制卵的孵化、降低J2期线虫幼虫活力、抑制线虫的入侵、延缓雌虫发育、减少产卵数目、降低作物根中根结和卵块数量，来实现稳定、高效、安全地防治根结线虫病害。近年来，内生真菌的作用机制得到广泛关注和研究，取得了显著进展。本文综述近年来内生真菌生物防治根结线虫机制的研究进展，总结了内生真菌直接攻击、资源竞争、代谢物胁迫、防御激活等4种主要机制，探讨其存在的问题，以期为进一步开发、应用植物内生真菌进行生物防治提供帮助。     

利用红树基因培育耐盐豇豆

土壤的盐渍化是影响农业与生态环境的一个严重问题。全世界的盆地约占陆地面积的三分之一,我国有一亿亩,而且有逐年增加的趋势。培育耐盐作物品种是利用盐碱地的一条重要途径,但是,用常规方法选育耐盐作物品种的工作进展缓慢,因此,人们试图通过生物技术提高作物的耐盐能力。植物抗盐性是一种十分复杂的性状,具体表现在避盐性和耐盐性两方面,即有的植物表现为对盐分排斥,不吸收;另外一些植物则表现为对高浓度盐分的忍耐。植物抗盐性是多性状的综合表现,普遍认为由位于不同染色体上的多基因调控。在目前识别与分离抗盐相关基因和同…     

诌议土壤盐渍化的生态防治

诌议土壤盐渍化的生态防治王春裕（中国科学院沈阳应用生态研究所,１１００１５）ＤｉｓｃｕｓｉｏｎｏｎＥｃｏｌｏｇｉｃａｌＣｏｎｔｒｏｌｏｆＳｏｉｌＳａｌｉｎｉｚａｔｉｏｎ．ＷａｎｇＣｈｕｎｙｕ（ＩｎｓｔｉｔｕｔｅｏｆＡｐｐｌｉｅｄＥｃｏｌｏｇｙ,Ａｃａ...     

基于电磁感应技术的土壤剖面盐分空间分布建模研究

土壤盐渍化问题是干旱半干旱地区农业发展的主要障碍,也是制约荒漠植物生长状况的关键因素之一,严重影响到绿洲生态环境的稳定与安全。研究土壤剖面盐分的分布情况,能及时探究盐渍化对生态的影响。以渭干河-库车河三角洲绿洲为研究靶区,利用电磁感应仪技术与传统采样方法获取该地区典型地块的土壤电导率,剖析其剖面分布特征,在建立磁感式表观电导率和土壤样本实测电导率之间的线性混合模型的基础上,采用自然邻近插值方法解析和评估研究区土壤剖面盐分的空间分布特征。结果表明:研究区土壤电导率具有较强的表聚性与空间变异强度,土壤主体属于中度盐渍化类型;基于各深度层土壤电导率与磁感表观电导率所构建的3种线性混合模型均能达到0.01的显著性水平,其中磁感表观电导率两种模式相结合解译模型预测精度最高;自然邻近法插值结果直观反映研究区土壤剖面盐分的空间分布状况,与水平模式和垂直模式相结合的土壤盐分解译模型相结合则能够更有效的提高土壤盐分空间分布的预测精度。研究结果表明,借助构建的土壤盐分解译模型可对研究区土壤盐渍化空间分布情况进行快速监测与评估,为该区土壤盐渍化的防治提供了一定的技术支撑。     

Spatial variability of soil salinity in Bohai Sea coastal wetlands,China: Partition into four management zones

Soil salinization constitutes an environmental hazard worldwide. The Bohai Sea coastal wetland area is experiencing dramatic soil salinization, which is affecting its economic development. This study focused on the spatial variation and distribution characteristics of soil salinity in this area using geostatistical analysis combined with the kriging interpolation method, based on a large-scale field investigation and layered soil sampling (0–30, 30–60 and 60–100 cm). The results revealed that soil salinity in these layers demonstrated strong variability, obvious spatial structure characteristics and strong spatial autocorrelation. Soil salinity displayed a significant zonal distribution, gradually decreasing with increasing distance from the coastline. Apart from the northern part of the study area, which appeared to be not affected by soil salinization, there were varying degrees of soil salinization in nearly 70% of the total area. With increasing soil depth, the areas of non-salinized and mild salinized soil gradually decreased, while those of moderate salinized and strong salinized soils increased. The area of saline soil first decreased and then increased. The study area could be divided into four management zones according to soil salinities in the top 1-m soil body, and utilization measures, adapted to local conditions, were proposed for each zone. The results of our study present an important theoretical basis for the improvement of saline soils, for wetland re-vegetation and for the sustainable utilization of soil resources in the Bohai Sea coastal wetland.     

Symbiotic nitrogen fixation in legumes: Perspectives for saline agriculture

Saline agriculture provides a solution for at least two environmental and social problems. It allows us to return to agricultural production areas that have been lost as a consequence of salinization and it can save valuable fresh water by using brackish or salt water to irrigate arable lands. Sea water contains (micro) nutrients that can provide the additional benefit of a reduced need of fertilization in saline agriculture. However, nitrogen is only present in very low quantities in seawater. A salt tolerant nitrogen-fixing legume used as a vegetable crop, fodder or green manure could increase the availability of soil nitrogen as well as the sustainability of saline agriculture while minimizing the application of inorganic fertilizer. Besides the use of salt-tolerant legumes as green manure, such species could also be useful in salinized areas as fodder and/or human food.In this review, we assess the feasibility of the use of legumes in saline agriculture. Most legumes are sensitive to salinity, as is the process of nitrogen fixation by microorganisms in the nodules of the legumes. First, we identify different steps in nodulation and their respective sensitivity to salinity. We will then look at the sensitivity of the process of nitrogen fixation in various crop and non-crop legumes, differing in their tolerance to salinity. We will also look into the differential response of nitrogen fixation and biomass production to salinity. Finally, a list of salt tolerant legumes is presented (derived from the HALOPH database). We then evaluate the applicability and perspective of salt tolerant legumes in saline agriculture considering the diversity in growth forms, ecotypes and economic uses.     

Influence of arbuscular mycorrhizae on heavy metal (Zn and Pb) uptake and growth of Lygeum spartum and Anthyllis cytisoides

The hypothesis tested in this paper is that, because the freshest water occurs in the largest soil pores (macropores), plants of low to moderate transpiration rate can survive in salinized soil because they preferentially extract water from macropores. The hypothesis predicts that a plant growing in a macroporous soil should have greater growth under a given salinity treatment than a similar plant growing in a soil with the same mineralogy but without macropores. This hypothesis was tested by growing bell pepper (Capsicum annuum) in the greenhouse in pots filled with either a commercial fritted clay (a highly macroporous soil) or the same clay ground to a finer texture and sieved to remove macropores and produce a microporous soil. The pots sat in pans filled with salt water. Half of the pots were irrigated once a day with fresh water and the other half received no fresh water. Plants growing in the macroporous soil had greater growth for a given salinity treatment than the plants growing in the microporous soil under both the irrigated and non-irrigated conditions. Under the irrigated condition for the highest salinity treatment, the non-reproductive fresh weight per plant, total dry weight per plant and fruit fresh weight per plant was 114 g, 12 g and 50 g, respectively, for the macroporous soil and 47 g, 4.5 g and 5 g, respectively, for the microporous soil. The results of this study provide evidence to suggest that a better understanding of what constitutes a good structure in a saline soil may aid us in our efforts to improve the management of saline soils. We suggest that it may be possible to increase the agricultural production on salinized land by no-tillage agriculture which preserves macroporosity. Possible obstacles could be the tendency of field saline-sodic soils to swell and the unavailability of relatively fresh irrigation water in areas with saline soils.     

黄河三角洲夏季典型田块土壤盐分的多尺度空间变异

土壤盐渍化严重阻碍黄河三角洲农业经济发展,掌握田间多尺度下土壤盐分的空间变异性特征对于盐渍土改良利用和农业生产有重要意义。选取黄河三角洲垦利区代表性夏季玉米田块,划分为大田、地块、垄间3个尺度,通过实地调查采样获取152 组电导率数据,运用经典统计学、地统计学和克里格插值方法,分析多尺度下田块土壤盐分的空间变异性特征及其尺度效应。结果表明: 试验区土壤为中度盐渍化,土壤盐分在3种尺度下均呈中等强度变异,从大田、地块到垄间,随着采样尺度的减小,土壤盐分的变异性趋强、标准差增大;垄间和地块尺度表现为强空间相关性,最优拟合模型为高斯模型,主要受结构性因素影响,大田尺度为中等空间相关性,最优拟合模型为指数模型,受随机性因素和结构性因素共同影响;不同尺度土壤盐分的空间分布特征有明显差异,小尺度的空间特征在大尺度下被掩盖,存在明显的尺度效应;垄间微域尺度下土壤盐分分布变异明显,土壤含盐量随微地貌由高到低、植被覆盖由疏至密而逐渐降低。     

Symbiosis between the root-nodule bacterium Sinorhizobium meliloti and alfalfa (Medicago sativa) under salinization conditions

Two hundred forty-three isolates of alfalfa root-nodule bacteria (Sinorhizobium meliloti) were obtained from nodules and soils sampled in the northern Aral region, experiencing secondary salinization. Isolates obtained from nodules (N isolates) were significantly more salt-tolerant than those from soils (T isolates) when grown in a liquid medium with 3.5% NaCl. It was found that wild species of alfalfa, melilot, and trigonella preferably formed symbioses with salt-tolerant root-nodule bacteria in both salinized and nonsalinized soils. Only two alfalfa species, Medicago falcata and M. trautvetteri, formed efficient symbioses in soils contrasting in salinity. The formation of efficient symbiosis with alfalfa in the presence of 0.6% NaCl was studied in 36 isolates (N and T) differing in salt tolerance and symbiotic efficiency. Fifteen isolates formed efficient symbioses in the presence of salt. The increase in the dry weight of the plants was 25–68% higher than in the control group. The efficiency of symbiotic interaction under salinization conditions depended on the symbiotic efficiency of the isolates under standard conditions but did not correlate with the source of root-nodule bacteria (soil or nodule) or their salt tolerance. The results indicate that the strains of root-nodule bacteria forming efficient symbioses under salinization conditions can be found.     

Salt tolerance conferred by overexpression of Arabidopsis vacuolar Na+/H+ antiporter gene AtNHX1 in common buckwheat (Fagopyrum esculentum)

Agriculture productivity is severely affected by soil salinity. One possible mechanism by which plants could survive salt stress is to compartmentalize sodium ions away from the cytosol. In the present work, transgenic buckwheat plants overexpressing AtNHX1, a vacuolar Na⁺/H⁺ antiporter gene from Arabidopsis thaliana, were regenerated after transformation with Agrobacterium tumefaciens. These plants were able to grow, flower and accumulate more rutin in the presence of 200 mmol/l sodium chloride. Moreover, the content of important nutrients in buckwheat was not affected by the high salinity of the soil. These results demonstrated the potential value of these transgenic plants for agriculture use in saline soil.     

土壤盐碱化程度及非毛管孔隙度对羊草群落生物量及优势度的影响

通过对不同盐碱化土壤上的羊草群落进行及定位连续观测,分析了它和土壤盐碱化程度及非毛管孔隙度之间的相互关系,探讨了盐碱生境下羊草群落生物量的形成规律以及土 盐碱化程度对其影响,结果证明,盐碱生境对羊草群落在一个生长季内的生物量形成过程无本质影响;群落的生物量随返青后天数增加而呈S型曲线上升,二者间的数学关系可用修改的Logistic方程Y＝Y m/1 Ae-bx C描述。土壤盐碱化程度可影响该方程的各参数,随土 盐碱化程度加剧,生物量最大增长值Ym和本底生物量C明显变小,到达S型曲线拐点的天数减少,羊草群落生态优势度随土壤盐度增大呈倒S型曲线下降,随土壤非毛管孔隙度增大而呈正S型曲线上升,三者之间的回归分析结果表明,土壤盐度和非毛管孔隙度都是影响优势度的不同忽略的重要因素,但前者的重要性大于后者。用方程可获得最佳拟合结果及3个生态因子相互关系的总体模型。     

盐渍化灌区土壤盐分的时空变异特征及其与地下水埋深的关系

土壤盐分空间变异特征和地下水埋深状况是指导灌区合理用水和防治土壤盐碱化的重要依据。运用经典统计学和地质统计学方法,结合GIS技术,分析了河套灌区沙壕渠灌域0-20 cm、20-40 cm、40-60 cm土壤EC值的空间变异特征及地下水埋深对土壤盐分分布的影响。结果表明:沙壕渠灌域土壤盐分Cv值在不同灌溉时期和不同土壤深度均大于36%,表现为强变异特征;各灌水时期和不同土壤深度土壤EC值均表现为中等强度的空间自相关性,表层0-20 cm土壤空间自相关程度最高;秋浇前不同层次土壤EC值的空间分布在灌域内从南到北呈增大趋势,秋浇后土壤含盐量的高值区在西北部或东北部;土壤盐分受地下水埋深影响显著,灌域内地下水埋深南深北浅,土壤盐分随地下水埋深的增大而减小,二者之间满足指数关系。因此,应采取合理措施控制地下水埋深,防止区域土壤盐渍化加剧。