燕麦对盐碱胁迫的反应和适应性

研究了自然盐碱胁迫对燕麦植株生长、水势、渗透调节物质质量分数以及对K 、Na 选择性吸收的影响,结果表明,随着土壤盐碱胁迫的增强燕麦植株生长受抑,叶片和根系的水势较对照均有所降低,其中裸燕麦较皮燕麦水势下降幅度大,表明裸燕麦比皮燕麦对盐碱胁迫更敏感。燕麦叶片内脯氨酸和可溶性糖累积。随着土壤盐碱胁迫的增强植株对Na 的吸收增加,对K 的吸收受到抑制,从而使w(Na )/w(K )和SNa K 值升高。在盐碱胁迫下,燕麦是以合成和积累有机溶质(脯氨酸和可溶性糖)以及吸收和积累无机离子(Na )来进行渗透调节,以适应盐碱胁迫。     

生物炭早期植物毒性评估培养方法研究

为更加科学地评估生物炭潜在植物毒性,采用生物炭(B)、生物炭+土壤(B+S)、生物炭水浸提液+土壤(AE+S)、生物炭+石英砂(B+Q)、生物炭水浸提液+石英砂(AE+Q)5种不同的培养方法进行早期植物毒性效应实验。比较分析不同培养方法中西红柿种子发芽率、根长、芽长对生物炭的响应。结果表明:在5种培养方法中,随生物炭剂量增加,西红柿种子发芽率、根长、芽长呈现先增后降的变化趋势。虽在低剂量生物炭处理下(10.0 g·kg~(-1)),种子萌发表现出促进作用。但随剂量增加,除B+S和AE+S外,均表现出一定的抑制作用,且当剂量为160.0 g·kg~(-1)时,抑制作用达到最大。对比有土和无土培养方法中种子萌发情况发现,在高剂量下,无土培养方法中种子发芽率,根、芽生长所受抑制作用显著高于有土培养方法。无土方法中,尤其AE+Q方法中,高剂量生物炭对种子发芽率、根长、芽长表现出最大的抑制作用,其中发芽率抑制率为91.1%,根长抑制率为77.7%,芽长抑制率为93.7%。综合比较分析,生物炭水浸提液+石英砂(AE+Q)的培养方法干扰因子少,可提高毒性响应灵敏度。因此,在生物炭早期植物毒性效应评估中,该法可作为推荐的培养方法。     

Salt stress induced alteration in growth characteristics of a grass Pennisetum alopecuroides

Salinity is one of the major abiotic stresses that adversely affect crop productivity and quality. The present investigation was carried out to study the alterations in the growth characteristics of a grass species, Pennisetum alopecuroides under the influence of sodium chloride (NaCl) salinity. From the results it is clear that shoot length of Pennisetum alopecuroides was increased by 13.17% at 100 mM NaCl concentration while the root length was observed to be increased at 50 mM NaCI concentration by 26.93%.Maximum height of the plant was observed by 18.23% at 50 mM while shoot to root ratio was higher at 300 mM concentrations by 29.17% increase over the control. Moreover, the maximum percent increase in leaf area was recorded as 11.17% (100 mM). Fresh weight was increased by 50.92% at 100 mM while dry weight of the experimental grass was increased by 33.64% at the same concentration of salt to the rooting medium while moisture percentage was increased to a maximum by 24.61% at 50 mM. It appears that the grass species studied exhibit a moderate salinity tolerance as far as linear growth of plant is concerned.     

Effect of different time of salt stress on growth and some physiological processes of <Emphasis Type="Italic">Avicennia marina</Emphasis> seedlings

Growth and physiological characters of Avicennia marina seedlings cultured under different levels of salinity were compared at 45 and 100 days after sowing. Based on the growth and physiological responses, the levels of salinity were grouped into two kinds, moderate (5–30‰) and extreme (40 and 50‰ as well as 0‰). Root and shoot length, leaf area, biomass of different organs, and net photosynthesis rate all showed a similar trend: the seedlings grew better at moderate levels of salinity but were adversely affected by extreme levels. Longer exposure (100 days) to salinity markedly enhanced the difference between the effects of the two levels on growth. By 45th day, the cotyledons had withered and fallen off. The concentration of ions (K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl⁻) and ash content of the cotyledons were determined before sowing and 45 days later. Ion concentrations and ash content of cotyledons were markedly lower at 45 days—lower than the initial levels—in seedlings irrigated with water at 0‰ salinity level. This suggested that the poor growth of these seedlings at 100 days may be due to lack of ions provided by the cotyledons. The high ion concentrations in the cotyledons grown at moderate salinity levels suggest that these organs may function as ion sinks at this stage, reducing the concentration of ions and consequent toxicity caused by excessive concentrations. Root biomass was higher than shoot biomass 45 days after sowing, whereas after 100 days, shoot biomass was higher. At the early stage of growth (45 days), the rate of photosynthesis at lower levels of salinity (0–30‰) was limited mainly by stomatal closure but at higher levels of salinity (40–50‰), other factors came into play. Later, at 100 days, the causes of reduced photosynthetic rate were other than stomatal closure at both low and high levels of salinity. This indicates that photosynthesis is affected by prolonged exposure to salt stress—including that caused by 0‰ salinity, as shown by poor growth of the seedlings.     

Changes in the fatty acid composition of Coscinodiscus eccentricus with culture-age and salinity

The fatty acid composition of the diatom Coscinodiscus eccentricus Ehrenberg, has been examined at six stages in the growth cycle for cells maintained in four different salinity media (20, 25, 30 and 35%) using gas-liquid chromatography. The predominant acids were those containing 16 carbon atoms (45 to 76% of the total); the higher percentages were found at the later growth stages. Several growth/salinity changes in the individual fatty acid compositions are described, and attention is drawn to the changes in the ratio of the 16:0:16:1 7 acids with growth in comparison with that previously published.     

盐胁迫对油菜幼苗生长和光合特征的影响

采用盆栽砂培试验,研究了不同浓度(0、50、100、200、300mmol·L-1)NaCl胁迫10和30d对油菜(Brassica napus)幼苗干质量、叶绿素(Chl)含量、净光合速率(Pn)、气孔导度(Gs)、细胞间CO2浓度(xi)、蒸腾速率(Rt)、水分利用效率(Ew,u)和气孔限制值(Ls)等的影响.结果表明,在NaCl胁迫下,油菜幼苗植株干质量显著降低,长期高盐胁迫下油菜干质量降低更显著;随NaCl浓度的增加,Chl含量、Chl a/Chl b比值均呈先升高后降低的变化趋势,处理10d,Chl含量、Chl a/Chl b比值在NaCl浓度为200mmol·L-1条件下达最大值,处理30d,在NaCl浓度为100mmol·L-1条件下达最大值.在50～100mmol·L-1NaCl胁迫下,油菜叶片的Pn、xi和Ls所受影响均很小;高盐胁迫下,其Pn、Gs、xi和Rt均显著下降,而Ew,u和Ls则显著上升.相关分析显示,植株干质量与Chl含量、Chl a/Chl b比值间无相关性,与Na+、Cl-含量,Ew,u和Ls间呈显著负相关(P＜0.01),与根冠比,K+、Ca2+含量,K+/Na+、Ca2+/Na+比值,K+与Na+的选择性比率[S(K+,Na+)],Ca2+与Na+的选择性比率[S(Ca2+,Na+)],Pn,Gs,xi和Rt间呈显著正相关(P＜0.01).上述结果表明,200mmol·L-1 NaCl胁迫10和30d、300mmol·L-1 NaCl胁迫10d,油菜幼苗光合抑制主要来自气孔限制,而300mmol·L-1 NaCl胁迫30d,气孔限制和非气孔限制在油菜幼苗光合抑制中均具有重要作用.Na+、Cl-、K+、Ca2+含量,Ew,u,Ls,根冠比,K+/Na+、Ca2+/Na+比值,S(K+,Na+),S(Ca2+,Na+),Pn,Gs,xi和Rt均可作为油菜生长盐适应性的评价指标.     

Entrainment of the larval release rhythm of the crab Rhithropanopeus harrisii (Brachyura: Xanthidae) by cycles in salinity change

Influences of salinity, Na, K, Ca and Mg on Na–K-ATPase activity in the posterior gills of Carcinus maenas (L.) have been investigated with respect to the role of the enzyme in hyperosmotic regulation. K and Mg ions were obligatory for enzyme activity. The dependence on the K concentration can be seen in a saturation curve of the Michaelis-Menten type. Low concentrations of Ca (0.2–3 mM) in the incubation medium strongly inhibited Na–K-ATPase activity. Activities inhibited by Ca could be reactivated to non-inhibited values by the addition of higher amounts of Mg (25 mM). Activity increased along with the salinity of the sea water used as incubation medium up to about 10 S. Here, maximum activity was observed. Further salinity increases of the incubating sea water were inhibitory. Salinity dependence is assumed to be based on Na dependence of the Na-pump. Comparative investigations of the Na–K-ATPase activity and its affinity to sodium in five species of decapod crustaceans indicated that levels of Na–K-ATPase differed in the posterior gills of stenohaline and euryhaline species. The results obtained confirm previous assumptions of a central role of the branchial Na–K-ATPase in hyperosmotic regulation. Properties of the Na–K-ATPase, such as affinity for substrates or dependence on ionic sea water constituents, are kept constant with respect to salinity changes. Modifications due to salinity only concern enzyme amounts especially in the posterior gills. The finding that the Na-pump is localized in basolateral parts of ion-transporting epithelial cells confirms the aforementioned results.     

盐雾胁迫对榄仁幼苗生长及体内矿质元素分布的影响

在温室培养条件下,用叶片喷雾的方式对盐生植物榄仁（Terminalia catappa）的幼苗进行NaCl胁迫处理,研究了盐雾胁迫对其生长、5种矿质元素（Ca2＋、Mg2＋、Na＋、K＋、Cl-）和灰分在幼苗不同叶龄叶片和叶片各部分分布的影响,以探讨盐雾胁迫下的盐害机理,以此指导实际工作中盐害诊断与预防措施,为筛选耐盐树种建设沿海防护林提供依据。结果表明：盐雾胁迫下榄仁幼苗的叶、茎、根生长比对照组缓慢,K＋在各叶片分区的分布差别较小,Ca2＋、Mg2＋、灰分在叶片中心区分布较多,Na＋和Cl-均向叶缘集中,且Na＋和Cl-质量分数显著增加（P〈0-05）,可见盐雾胁迫下榄仁幼苗叶片盐分较易集中在叶尖、叶缘,这与叶片病斑多分布于叶尖、叶缘的症状相符。盐雾胁迫下榄仁幼苗叶片的灰分质量分数在叶片中心区分布最多,并呈现老叶〉成叶〉新叶,而且随胁迫时间增加呈升高趋势,叶片不同部位和不同叶龄的灰分质量分数都显著高于对照组（P〈0-05）,故盐雾胁迫促进植物体灰分积累。盐雾胁迫下榄仁幼苗的 K＋、Na＋、Cl-在新叶分布最多,Ca2＋在老叶分布最多,Mg2-在成熟叶分布最多,可见新叶对盐雾胁迫最敏感。不论是在叶片不同部分、不同叶龄的分布,还是在盐雾胁迫下5种矿质元素质量分数的变化上,榄仁幼苗体内的Na＋-Cl-存在极显著强正相关（P〈0.01）。     

含铅、镉重金属细颗粒物对几种陆生植物的暴露危害

大气重金属细颗粒物复合污染对陆生植物早期发育及幼苗生长的影响研究近年来成为大气科学与生态毒理学交叉领域研究的热点和难点。通过搭建合理的暴露场景,模拟严重大气污染浓度条件下,含Pb、Cd细颗粒物对黄瓜、小麦、西红柿和玉米4种受试植物出苗、幼苗生长期内茎高和鲜重等生物量的影响。结果显示,暴露处理组4种受试植物陆上部分对Cd元素的吸收增量变化范围为0~0.025 mg·kg-1;对Pb元素的吸收增量变化范围为0.020~0.292 mg·kg-1。暴露处理组4种受试植物出苗抑制率变化范围为0%~30%;茎高抑制率变化范围为-3%~14%;鲜重抑制率变化范围为-12%~3%。由此可见,在试验周期内,含Pb、Cd重金属细颗粒物复合污染对几种植物的陆上部分生物量的抑制作用不明显,甚至有积极的刺激作用。与空白对照组相比,暴露处理仅对小麦出苗抑制产生显著性差异,并显现协同效应。说明几种受试植物在现有暴露环境下,对设定浓度的污染物敏感性较低,受危害程度不大。     

Larval growth in the estuarine crab Chasmagnathus granulata: the importance of salinity experienced during embryonic development, and the initial larval biomass

The importance of salinity experienced during embryonic development and initial larval biomass on larval growth was studied in the South American estuarine crab Chasmagnathus granulata. Ovigerous females were maintained at three salinities (15, 20, and 32‰) from egg laying to hatching of zoea l. Larvae from all treatments were reared under constant conditions of photoperiod (12∶12), temperature (18°C), and salinity (first instar at 20‰, subsequent instars at 32‰). Biomass was measured as dry weight, carbon, and nitrogen content per individual at egg laying, hatching of zoea l, premoult zoea l, and zoea 4, and in 8-day-old megalopa. From hatching to premoult zoea 4, biomass was higher for larvae from prehatching salinities of 15 and 32‰. There was a significant positive correlation between biomass at hatching and at premoult zoea l and zoea 4. Accumulated biomass during zoeal stages tended to be higher for larvae from broods with higher biomass at hatching, although this trend was not always significant. Zoea 4 either directly metamorphosed to megalopa or moulted to zoea 5, following, respectively, a short or long developmental pathway. The proportion of zoea 4 that followed the long pathway was negatively correlated with biomass of zoeal stages. Biomass at hatching was correlated with biomass of megalopae developed through the short pathway, although it was not correlated with the accumulated biomass at this stage. Megalopae developed through the long pathway (i.e. metamorphosed from zoeae 5) had higher biomass than those from the short pathway. The present results suggest that prehatching salinity and initial egg and larval biomass can be very important for larval growth. Published online: 9 August 2002     

Consequences of maternal isolation from salinity stress for brooded embryos and future juveniles in the estuarine direct-developing gastropod Crepipatella dilatata

At reduced salinities, brooding females of some gastropods and bivalves may isolate their mantle cavities from the environment for several days, maintaining internal osmotic concentration but causing severe declines in dissolved oxygen and pH, and increases in ammonia and other toxic substances in the mantle fluid. This study in November–December examined the immediate consequences of such stresses for brooded embryos of Quempillén estuary gastropod Crepipatella dilatata, in terms of time to juvenile emergence and rates of embryonic growth [measured as shell length (SL)]. Juveniles were also monitored for latent effects on feeding rates, oxygen consumption, and growth for the first 4 weeks after emergence into normal salinity seawater. An acute salinity stress lasting 3 days applied to females that were brooding pre-shelled or intermediate-shelled stages increased embryonic incubation periods, but without affecting SL at emergence. Growth rates were reduced for encapsulated embryos regardless of the stage at which the salinity stress was applied. Latent effects on juvenile development included slower shell growth and reduced rates of oxygen consumption and feeding. These effects were sustained for the first month after release from the female. The results suggest that marked reductions in salinity lasting for several days indirectly but negatively affect the development of brooded embryos of C. dilatata and also affect the juveniles for at least several weeks following their release, even after salinity has returned to normal.     

Temperature and salinity interactively impact early juvenile development: a bottleneck in barnacle ontogeny

When juvenile mortality or juvenile growth is impacted by temperature and salinity, these factors have a substantial effect on recruitment success and population dynamics in benthic ecosystems. Using freshly settled cyprids of Amphibalanus improvisus, we investigated the combined effects of temperature (12, 20 and 28 °C) and salinity (5, 15 and 30 psu) on early juvenile stage performance. Mortality as well as size (basal diameter, dry weight, and ash-free dry weight) was monitored for a period of 40 days. Mortality was high (42–63 %) during the first week following attachment, regardless of the temperature and salinity treatments. Subsequently, mortality and size were interactively influenced by temperature and salinity. Highest mortality and lowest size of juveniles occurred at lowest temperature (12 °C) and salinity (5 psu). Apparently, low temperature (12 °C) narrowed the barnacles’ salinity tolerance. Juvenile barnacles constructed more shell material compared to body mass at high temperature and high salinity, while a reverse situation was observed at low temperature and low salinity. Our results demonstrate that environmental changes can directly and/or indirectly alter patterns of survivorship and size. Warming and desalination as predicted for the Baltic Sea in the course of climate change may, however, act antagonistically and compensate each other’s isolated effect on barnacles.     

Einfluß von salzgehalt und temperatur auf entwicklung,wachstum, fortpflanzung und energiebilanz von Artemia salina

The influence of salinity and temperature on various life processes of Artemia salina (L.) from the Great Salt Lake, Utah, USA, was investigated. Hatching rate, hatching success, energetics and metabolism of hatching, growth rate, maturation rate and reproductive rate were measured at all combinations of 4 temperature levels (10°, 15°, 20°, 30°C) and 4 salinity levels (5, 15, 32, 70‰S). Optimal temperature-salinity combinations differ for different life cycle stages and parameters. The hatching rate rises with increased temperature and sinks with increased salinity. Hatching success is optimal at 20°C and 32‰S. Larval growth is best at 30°C and 15‰S; however, the maximum growth is attained at 20°C and 32‰S. Maturation rate, onset of reproduction, interval between clutches as well as the total number of offspring are primarily influenced by temperature, whereas the clutch size is a function of salinity. As the temperature is lowered, the capacity to survive low salinities is decreased. At low temperature, reproduction is only possible at high salinity. The energy consumption of the hatching embryo is primarily determined by the salinity level of the medium and is directly proportional to it. Carbohydrate consumption is under all conditions greatest by weight, but measured by its caloric contribution the relative importance decreases with increased energy drain. Additional energy requirements, particularly during the later stages of hatching, are met by raising fat and protein metabolism, fat being the main energy reserve.     

除草剂对强筋小麦产量及生理特性的影响

在盆栽和大田条件下,研究4种除草剂对2个强筋小麦品种(“临优145”和“临汾138”)产量及生理特性的影响.结果表明,在推荐用量下,除草剂对成穗数、穗粒数和穗长的影响较小,对株高、千粒重、旗叶叶绿素相对含量(SPAD值)、净光合速率及灌浆进程影响较大.2,4-D丁酯使旗叶SPAD值、净光合速率一直较低,千粒重降低;“巨星”在灌浆前期使旗叶SPAD值、净光合速率保持较高,灌浆中后期快速下降,并使灌浆持续时间相对缩短,千粒重最低,较对照分别低2.40g和0.84g;而“世玛”使灌浆前中期SPAD值和净光合速率较低,但下降相对缓慢,使灌浆持续时间分别延长3.48d和1.86d,“库”容增加,千粒重分别提高1.18g和1.05g,同时具有一定的降低株高作用;“骠马”虽使灌浆持续时间延长,但影响相对较小.除草剂对籽粒生长模型参数的影响,品种间存在一定差异,除草剂对“临优145”初始生长势、快增期和缓增期持续时间、快增期和缓增期平均灌浆速率影响较大,而对“临汾138”的这些指标以及总灌浆持续时间影响较大.分析旗叶光合特性、灌浆进程、千粒重及产量间的相关性,表明除草剂主要是通过旗叶生理和灌浆进程来影响千粒重和产量.图1表7参19     

Detoxification of 4-chlorophenol in TiO2 sunlight system: effect of raw and treated solution on seed germination and plants growth of various sensitive vegetables

The mineralization and detoxification of 4-chlorophenol (4-CP) were studied using a TiO₂-paper/sunlight system. The possibility of reusing the photocatalyst was examined to determine the cost effectiveness of the method. Experiments were performed to establish optimum conditions for 4-CP removal. Phytotoxicity of photo-treated and raw 4-CP (100 mg L^?1) solutions on seed germination and plant growth were carried out with the aim of water reuse and environment protection. The seeds irrigated with raw 4-CP solution showed lower sprout length while increase in sprout length was observed with the photo-treated solution for tomato (Lycopersicon esculentum), lettuce (Lactuca sativa), onion (Allium cepa), and turnip (Brassica rapa). Plant growth tests with the photo-treated 4-CP solution did not affect the leaf numbers compared to those irrigated with tap water. Photo-treated 4-CP solution can be used for irrigation in agriculture.     

谷子根系对群体压力胁迫的生物学响应

采用根管土柱栽培的方法,比较了在相同根管土柱体积上种植不同株数谷子时谷子根系的主要特征,如根系数量,根系入土最大深度,根系SOD、POD活性,总根长,根系MDA含量及根系总吸收面积与活性吸收面积等对群体密度变化的可塑性.结果表明,不同群体下,谷子单株根数前期差异小,中后期差异大;而单位土体中的根量前期差异大,后期差异小.群体大(密度高),谷子根量、总根长及根系总吸收面积与活性吸收面积达到高峰的时间早,但衰亡时期也早,且入土深度较浅.群体小根量高峰出现得迟但维持的时间较长,根系在土体中的延伸深度也较大,有利于后期营养的获取和产量的提高.群体在作物生长中起着量的决定作用,而个体生长发育由于群体不同而引起质的差异.在生产上要想获得理想的产量,既要有足够量的保证,又要求达到一定质的标准,以使群体与个体协调发展.表4图2参18     

Variations in the biochemical composition of the diatom Coscinodiscus eccentricus with culture age and salinity

Cultures of the marine diatom Coscinodiscus eccentricus Ehrenberg were grown at four salinities, namely 20, 25, 30 and 35%. The changes in the carbohydrate, protein, silicon and pigment concentrations of the cells were studied throughout the growth cycles in these salinities. The carbohydrate content, expressed as a percentage of the cell dry weight, increased in all cultures during the lag and early log phases. It later fell, sharply at first, as it was used up faster than it was produced. It was not stored during the stationary phase. The protein percentage composition built up to a peak at different stages during the exponential or stationary growth stages, depending on the salinity, but was later respired. The silicon percentage of the dry weight usually decreased during the log phase, as the cells were dividing before becoming fully silicified, and remained low in the stationary phase due to an increase in the volume of the cells. The changes in the frustular thickness were also calculated. The values ranged from 0.24 to 0.35 μm (at the beginning and end of the experiments) to 0.15 μm during the log growth phase. The pigment content was always low. The lipid composition of the cells was calculated by difference. It was usually low during the exponential growth phase, but was accumulated during the stationary phase. The point at which this accumulation began was associated with the time when protein respiration started.     

Somatic condition of the fish, Notopterus notopterus (Pallas) during different phases of the reproductive cycle

The study on the mathematical relationship between length and weight of fishes has considerable importance in fishery research especially for the study of fish population dynamics and patterns of growth in fish stocks. This aspect is useful in rationally managing the population of fishes, and is an index of relative robustness of the fish). Variations from expected weight or length of an individual fish or group of fish indicate the general well being and state of gonadal development. The condition of fish can be influenced by the onset of maturity. The results indicate that the overall condition of the female and male fish seems to get improved towards the approach of maturing and mature stages of the gonads during pre-spawning phases. The reduction in the condition factor (K) and somatic condition factor (Ks) during spawning phase may be because of the fish becoming exhausted due to spawning activity. Although improvement in the condition of the fish was observed on the approach of breeding period, the overall condition seems to be better in the aquatic body from which the fish was collected.     

Energy expended on growth and gonad output in the ribbed musselAulacomya ater

Length/weight relationships have been computed for shell, flesh and byssus ofAulacomya ater (Molina) and energy values used to convert the weights to energy equivalents. Shell accounts for some 26% of total body energy, while the contribution of the byssus declines from 15 to 8% during growth. Observations of juvenile growth rates have been used to generate a Gompertz growth equation which predicts attainment of maximum length (90 mm) after 11 years. Reproductive condition has been assessed by monitoring seasonal fluctuations in the flesh weight of standard-sized individuals, calculated from monthly length/weight regressions. There appear to be three spawnings, of variable date and intensity, each year. From the above data, annual energy expenditure on growth and gonad output has been calculated for individuals of various sizes. The ratio of total production to biomass is a declining clining function of shell length, dropping from 29.5 at 5 mm to 0.8 at 85 mm. The proportion of total production expended on gamete output increases steadily from 25% at attainment of maturity (15 mm) to 81% at 85 mm length. The considerable effects of changing size composition on the amount and type of production in natural populations are discussed.