NaCl胁迫对超大甜椒种子萌发及幼苗生长的影响

以超大甜椒种子和幼苗为材料,采用水培法研究低、中、高浓度(50、150、250 mmol·L-1)NaCl胁迫对其种子萌发和幼苗生长的影响.结果显示:(1)低浓度NaCl处理促进种子萌发,而中、高浓度NaCl处理抑制种子萌发;NaCl处理第18天时,高浓度NaCl处理植株全部死亡,其余各处理植株苗高、叶面积、地上部鲜重和干重均随处理浓度升高而下降,但低浓度NaCl能刺激超大甜椒的根系生长.(2)低、中浓度NaCl处理时,植株叶绿素含量未受到大的影响,类胡萝卜素含量却随胁迫时间延长微量升高;在盐胁迫7 d的周期内,低、中浓度NaCl处理植株MDA含量、SOD活性和可溶性糖含量均随浓度升高及时间延长显著增加,脯氨酸含量在低浓度下变化不明显而中浓度下显著升高;在高浓度NaCl处理3 d中,MDA含量急剧升高,SOD活性先升高后下降,脯氨酸和可溶性糖含量显著增加.研究发现,NaCl胁迫浓度越高对超大甜椒种子萌发和幼苗生长的抑制效应越明显;低中浓度NaCl处理幼苗能通过自身的抗氧化酶清除系统和渗透调节物质来抵抗胁迫引起伤害,类胡萝卜素可能也有一定的抗胁迫作用,而高浓度NaCl处理增加了膜脂过氧化程度,严重影响了活性氧和渗透调节物质的正常代谢.     

长时间盐胁迫对苋菜叶片细胞结构的影响

生长40d的苋菜秧苗用300mmol·L-1的NaCl处理28 d后,生长受抑,叶面积变小,叶绿素含量降低;叶肉增厚、微管束变小,细胞内容物减少、叶绿体收缩、液泡扩大,细胞核染色程度变浅,形状拉长;细胞内淀粉含量增加.     

NaCl胁迫对西瓜幼苗生长和光合气体交换参数的影响

以早春红玉品种为材料,采用营养液水培法,研究了不同浓度NaCl胁迫对西瓜幼苗生长、叶片光合气体交换参数、质膜透性和脯氨酸含量的影响.结果表明:25 mmol·L-1NaCl处理9 d后对西瓜幼苗生长有促进作用,>75 mmol·L-1NaCl处理则显著抑制幼苗生长;NaCl处理显著提高了叶片光合色素含量,并在100 mmol·L-1NaCl处理下达到最大;叶片净光合速率、气孔导度和蒸腾速率均随NaCl浓度提高而显著降低;胞间CO2浓度随NaCl浓度提高呈先降低后升高的趋势,在75 mmol·L-1NaCl处理下降到最小;气孔限制值随NaCl浓度提高而增加,在75 mmol·L-1NaCl处理下达到最大值后趋于稳定;水分利用率随NaCl浓度提高呈先增加后降低的趋势,在75 mmol·L-1NaCl处理下达到最大;叶片质膜透性和脯氨酸含量均随NaCl浓度提高而显著增加.结果说明:NaCl胁迫显著抑制了西瓜叶片光合作用,且低浓度处理下光合速率降低的主要原因是气孔因素限制,高浓度胁迫下则转变为非气孔因素限制.     

NaCl胁迫对黄花菜生长和生理特性的影响

为探明黄花菜的耐盐性及其生理机制,该试验以大同黄花菜为材料,采用砂培法,以正常营养液为对照（CK）,用不同浓度（50、100、150、200、250 mmol·L^-1）NaCl溶液浇灌大同黄花菜,分别于处理后5、10、15、20、25 d测定生长指标和生理指标,以明确NaCl胁迫对大同黄花菜生长、膜脂过氧化以及有机渗透调节物质含量的影响。结果表明：（1）随NaCl浓度提高,黄花菜根长和根系鲜质量先增大后减小,其他生长指标则逐渐显著降低,同时地上部含水量变化较小,根系含水量明显增加。（2）黄花菜叶片叶绿素a、叶绿素b和类胡萝卜素含量随NaCl浓度提高均明显降低。（3）随NaCl浓度提高,黄花菜叶片丙二醛含量和POD活性逐渐显著增加;抗坏血酸含量在胁迫后20 d明显增加,25 d时呈先增加后降低的变化趋势,并在150 mmol·L^-1 NaCl胁迫下达到最大值;SOD活性在处理后10 d先增加后降低,在200 mmol·L^-1 NaCl处理下达到最大值,15 d后随NaCl浓度提高而显著增加。（4）随NaCl浓度提高,叶片脯氨酸含量逐渐显著增加,可溶性糖含量明显降低,可溶性蛋白含量在短期内逐渐增加,在胁迫15 d后呈先增加后降低的变化趋势,在150 mmol·L^-1 NaCl下达到最大值。研究发现,NaCl胁迫对黄花菜叶片光合色素合成的抑制和过氧化伤害程度均随浓度增加而增大;植株自身抗氧化能力和渗透调节能力在盐胁迫下明显提高,一定程度上缓解了盐胁迫对其植株的伤害,但仍不足以消除胁迫带来的不利影响,使得黄花菜植株生长受到显著抑制;黄花菜对NaCl胁迫的耐性较强,植株在250 mmol·L^-1高盐胁迫下仍能存活。     

NaCl胁迫对秋茄幼苗根系抗氧化系统的影响

为探讨红树植物秋茄(Kandelia candel)幼苗根系抗氧化系统对盐胁迫的生理响应,以Hoagland完全营养液沙培秋茄幼苗60 d后,用不同浓度NaCl处理秋茄根系1、3、5、7 d,对其生理生化指标的变化进行研究。结果表明,胁迫相同天数,200和400 mmol L~(-1) NaCl处理的秋茄根系O_2~(-·)和H_2O_2含量保持较低水平,而600 mmol L~(-1) NaCl处理的则明显增加;MDA含量在200和400 mmol L~(-1) NaCl处理下保持稳定,而600 mmol L~(-1) NaCl处理的显著升高;SOD、POD、CAT、APX和GR活性随NaCl浓度升高总体上表现先上升后下降的趋势,处理3和5 d后的酶活性均显著高于对照,而600 mmol L~(-1) NaCl处理7 d后的酶活性明显低于对照;AsA和GSH含量总体上均明显高于对照。因此,秋茄幼苗是通过根系功能较强的抗氧化系统清除活性氧以提高植株的耐盐性。     

NaCl胁迫对烤烟K326种子萌发及幼苗生理生化特性的影响

以烤烟品种K326为材料,研究不同浓度NaCl胁迫处理下种子萌发及幼苗生理生化指标的变化。结果表明,低浓度NaCl处理对幼苗生长具有一定的促进作用,而高浓度NaCl胁迫处理具有显著或极显著抑制作用;随着NaCl处理浓度的增加,发芽势、发芽指数、简单活力指数、形态指标、钾离子含量、单株干鲜重均呈明显下降趋势,而钠离子含量则相反;随着NaCl处理浓度的增加以及胁迫时间的延长,K326幼苗叶片中丙二醛、游离脯氨酸、可溶性糖含量及电解质渗透率均呈上升趋势,而可溶性蛋白、叶绿素含量及根系活力变化则相反。     

NaCl胁迫对马蔺生长及生理生化指标的影响

采用水培法,以1/2Hoagland溶液为基础培养液,研究了1、2、3、4、6、8和10 g·L-1NaCl胁迫处理对马蔺[Iris lactea Pall.var.chinensis(Fisch.)Koidz.]幼苗部分生长和生理生化指标的影响.结果显示:随NaCl质量浓度的提高,马蔺幼苗的株高和根长、地上部分和根及全株干质量逐渐减小,但在1 g·L-1NaCl胁迫条件下,株高和地上部分及全株干质量均显著高于对照.随NaCl质量浓度的提高和胁迫时间的延长,马蔺幼苗叶片的相对电导率和丙二醛(MDA)含量总体上呈逐渐升高的趋势;其中,用1～4 g·L-1NaCl胁迫处理7或14 d,相对电导率有小幅增加但与对照差异不显著;用1～8 g·L-1NaCl胁迫处理7 d,MDA含量与对照差异不显著.叶片叶绿素和脯氨酸含量以及超氧化物歧化酶(SOD)活性则随胁迫时间的延长呈先升后降的趋势,在胁迫的14或21 d各指标达到最高值.随NaCl质量浓度的提高,脯氨酸含量和SOD活性均不断增加且总体上显著高于对照;叶绿素含量则随NaCl质量浓度的提高出现低浓度升高、高浓度降低的趋势,其中3和4 g·L-1NaCl胁迫处理组叶绿素含量最高;各处理组的可溶性蛋白质含量在处理的第7大或第14天与对照无显著差异,第21天则随NaCl质量浓度的提高呈低浓度升高、高浓度降低的趋势,而第28天则随NaCl质量浓度的提高逐渐降低.总体上看,低质量浓度和短时间的NaCl胁迫对马蔺生长和代谢的抑制作用不明显甚至略有促进作用,而高质量浓度和长时间的NaCl胁迫则具有明显的抑制作用.在实验结束后全部供试植株均存活,结合生长和生理生化指标的测定结果,初步判定马蔺对NaCl胁迫具有较强的耐性.     

四季竹对不同浓度NaCl胁迫的生理响应

以夏秋季优良笋用竹种四季竹盆栽苗为材料,研究了土壤中1‰~6‰浓度NaCl(干重)处理对四季竹叶片脱落率、离子渗漏率、丙二醛(MDA)含量、抗氧化酶活性以及渗透调节物质含量的变化特征,以探讨四季竹的抗盐机理。结果表明:(1)随NaCl浓度的增大和处理时间的延长,四季竹叶片脱落率逐渐增加;四季竹在1‰~2‰NaCl浓度下的土壤中生长良好,在3‰~5‰浓度下随处理浓度的增大伤害逐渐加重,但这种伤害是可逆的,6‰是四季竹的半致死盐浓度。(2)叶片离子渗漏率随NaCl浓度的增大而显著增大,在6‰浓度处理下随处理时间的延长近直线升高,在3‰~5‰浓度下先升高后降低,而在1‰~2‰浓度处理下变化平缓且与同期对照无显著差异;叶片MDA含量随NaCl浓度的增大而增加,随处理时间的延长先增加后降低。(3)四季竹叶片SOD和POD活性在胁迫3~15 d均出现先下降后上升的过程,其有一定的锻炼适应性;叶片脯氨酸含量随NaCl处理浓度的增大而增加,其随处理时间的延长在1‰~2‰浓度处理下变化平缓,在3‰~6‰浓度处理下显著增加后减小;各浓度处理的可溶性蛋白含量随处理时间的延长先增加后减小,但均高于对照。研究发现,四季竹是较耐盐竹种,其可以通过调控自身保护酶活性和渗透调节物质含量来有效缓解盐胁迫伤害,从而表现出一定的耐盐能力。     

NaCl胁迫对小麦幼苗生长、叶绿素含量及Na^＋、K^＋吸收的影响

对宁夏地区种植的几个春小麦品种和国内外引进的抗盐小麦材料的幼苗进行不同浓度NaCl胁迫处理,结果表明：NaCl胁迫对小麦幼苗地上部生长抑制显著,而对地下部生长影响较小;NaCl胁迫对小麦幼苗的胁迫主要是离子伤害,而渗透胁迫不明显;随NaCl浓度的增加,叶绿素含量显著下降,同时植株中Na^ 含量增加,K^ 含量下降,K^ /Na^ 降低;不同品种对不同浓度NaCl的胁迫反应不同。     

瓜多竹(Guadua amplexifolia)对NaCl胁迫的生理响应

为了解瓜多竹（Guadua amplexifolia）的耐盐性,对2年生盆栽苗进行了不同浓度NaCl胁迫处理,结果表明：以处理40d的叶片脱落率将盐害程度分为无盐害（〈10％）、轻度盐害（10％-50％）和重度盐害（〉50％）3级;随着胁迫时间的延长,离子渗漏和MDA含量均呈上升趋势,40d时0．30％及以上浓度的NaCl处理水平相对电导率均〉50％,MDA含量显著高于低浓度处理;POD和SOD活性随胁迫时间的延长呈先升后降规律,40d时0．20％NaCl处理的POD活性最高,0．30％NaCl处理的SOD活性最高;游离脯氨酸和可溶性蛋白等渗透调节物质也呈先升后降规律,40d时0．30％及以上浓度的NaCl处理的可溶性蛋白和游离脯氨酸含量显著下降,0．20％及以下浓度的NaCl处理则继续上升。综合上述生理指标的反应,土壤含盐量0．30％及以上时不适合该竹种生长。     

Reliability of Analyses of Hg,Fe, Ca,K, P,pH, Alkalinity,Conductivity, Hardness and Colour from Lakes

The aim of this report has been to present results concerning analytical quality controls of Hg analysis of fish and sediment, analyses of Fe, Ca, total-P, K, pH, alkalinity, conductivity, colour and hardness (Ca + Mg) of lake water samples. Despite the fact that these are standard parameters in many regular water control programs, there are major differences in the reliability with which these parameters can be determined. The focus here is on an overall inter-laboratory comparison between the parameters. Six laboratories have been involved in the analysis. Selected results: pH gives the lowest (average) relative standard deviation (error), about 2 %; conductivity gives an error of about 5–7 %; alkalinity yields an average error of as much as 13–25 %, which is the largest among the parameters studied here; colour also gives a high error, 9–15 %; hardness gives a relative standard deviation of about 6–7 %. Of the other parameters (i. e., Hg, Fe, Ca and P), Hg gives the best reliability and Fe and P the lowest. To have knowledge of the reliability of the analytical data is of paramount importance in most control programs and research projects.     

Distribution of N,P, K,Ca, Mg,S, Zn,Fe, Mn and Cu in groundnut

Summary Concentration of N, P, K, Ca, Mg and S in summer groundnut crop was higher than in kharif while Zn, Fe, Mn and Cu contents were higher in summer crop. Kernel's N, P and Zn; Leaflet's Ca and Mn; Stem's K and Fe; Root's S and Cu and Petiole's Mg contents were highest. Shell's N, P, K, Mg, S, Zn and Cu; Kernel's Ca, Fe and Mn contents were the least. N, P, K, S, Zn and Cu concentrations decreased linearly as the crop grew. Ca, Mg, Fe and Mn concentrations did not display any distinct pattern. Ca concentration was positively correlated with pod yield in both the seasons.     

Uniform hypothesis of cell behavior--movement, contact inhibition of movement, adhesion, chemotaxis, phagocytosis, pinocytosis, division, contact inhibition of division, fusion.

The cell has been represented as a charged liquid drop. Contrary to the DLVO-theory, the effect of the surface potential upon the value of the interfacial tension of the cell membrane has also been taken into consideration. The cell membrane has visco-elastic properties and its constituents may move against each other. Cell movement is caused by the appearance of a small number of the electrically charged constituents of the cell membrane on the leading edge of the cell. This produces a local decrease in the surface tension and the cell membrane expansion. At the moment of contact between two cells proton transfers occur between the strongly negatively charged microvilli of one cell and the body of the other, analogous to a condenser breakdown. This, through the effect on the surface tension, causes contact inhibition of movement. The distribution of the proton dissociable groups modifies the interaction between the cells (differentiation) and between the cell and the substratum (adhesion). Adsorption of the charged compounds at the surface of the cell membrane, decreasing the surface potential and increasing the surface tension, causes the phenomena of chemotaxis, phagocytosis and pinocytosis. Cell division, considered in the terms of the surface energy, requires an adequate supply of considerable quantities of energy inversely proportional to the surface potential value. In case of a reduction of the distance between the cells, their surface potential and the energetic barrier of the cell division processes increases, and causes contact inhibition of cell division. Due to their high charge, division of neoplastic cells is inhibited much later than division of normal cells, or is completely ininhibited due to geometric conditions. Fusion of the cell membrane in the intra-cellular and intercellular processes is a reverse process in relation to the cell division.     

The effect of malathion,diazinon, and various concentrations of zinc,copper, nickel,lead, iron,and mercury on fish

Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive to diazinon. Long-term exposure to pesticides modified morphology and behavior. The LC50-96 values for Cu, Hg, and Pb were 0.3, 0.16, and 0.44, respectively, for smaller fish and 1.0, 0.77, and 1.33, respectively, for larger fish. Replicate LC50 values for Zn, Ni, and Fe were somewhat variable, and for these metals, the size of the fish seemed to affect response because LC50 values increased as fish size increased. Cooper, Pb, Zn, and Fe residues following exposure to sublethal concentrations of these metals for 15 d were significantly greater in whole juvenile common carp than in controls.     

The Effect of Age and Gender on Al, B, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Na, P, S, Sr, V, and Zn Contents in Rib Bone of Healthy Humans

The effect of age and gender on major, minor, and trace element contents in the intact rib bone of 80 relatively healthy 15–55-year-old women and men was investigated. Contents or upper limit of contents of 16 chemical elements in the rib bone were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Mean values (M?±?SΕΜ) for the mass fraction of Ba, Ca, Cu, Fe, K, Li, Mg, Na, P, S, Sr, and Zn (milligram per kilogram of dry bone) were as follows: 2.54?±?0.16, 171,400?±?4,050, 1.35?±?0.22, 140?±?11, 1,874?±?71, 0.049?±?0.011, 2,139?±?38, 5,378?±?88, 75,140?±?1,660, 1,881?±?51, 291?±?20, and 92.8?±?1.5, respectively. The upper limits of contents of Al, B, Mn, and V were <7.20, <0.65, <0.36, and <0.03, respectively. Statistically significant tendency for the Ca, Mg, and P content to decrease with age was found in the human rib bone, regardless of gender. The mass fraction of Fe in the male rib bone increases with age. It was shown that higher Ca, Mg, Na, P, and Sr mass fractions as well as lower Fe content were typical of female ribs as compared to those in male ribs.     

Further studies of the sieve-element plastids of theCaryophyllales includingBarbeuia,Corrigiola, Lyallia,Microtea, Sarcobatus,andTelephium

The sieve-element plastids of 69 species of theCaryophyllales were investigated by transmission electron microscopy. All contained the specific subtype-P3 plastids characterized by a peripheral ring of protein filaments. The presence or absence of an additional central protein crystal and their shape being either polygonal or globular as well as the average sizes of the sieve-element plastids are useful features in the characterization of some families.—Barbeuia contains sieve-element plastids that confirm its placement within thePhytolaccaceae. Lyallia differs fromHectorella by including small starch grains in their sieve-element plastids, which otherwise by their globular crystals negate a closer connection to theCaryophyllaceae. The lack of a central protein crystal in its form-P3fs plastids placesMicrotea best within theChenopodiaceae. Sarcobatus, a so far uncontested member of theChenopodiaceae, contains form-P3cf plastids, i.e., including a central crystal not found elsewhere in this family.Telephium andCorrigiola, shifted back and forth betweenMolluginaceae andCaryophyllaceae, have form-P3cf(s) plastids with a polygonal crystal which favor their placement within theCaryophyllaceae.     

Translocation of radionuclides of Co, Zn, Se, Rb, Y, Tc, and Re into organs of tomato plant via roots

The translocation of the radionuclides of Co, Zn, Se, Rb, Y, Tc, and Re into red and green fruits, flesh, seeds, rind, calyxes, flower, leaves, and stems via the root of the tomato plant at two different growth stages was studied by a multitracer technique. The contents (%/g) of Co, Zn, Se, and Y in the roots were the highest among the organs, but only small amounts of them were translocated into the aerial parts after 5 d cultivation with a multitracer. In contrast, Rb, Tc, and Re showed rapid translocation into the stems and leaves from the root. In the plants cultivated for 95 d with a multitracer, Zn, Se, and Rb distributed in all of the organs, Co in the organs except for flowers, and Y, Tc, and Re in the limited organs. The translocation ratio of the elements for the edible part of the plants cultivated for 95 d decreased in the order of Rb>Zn>Co≈Se>Tc≈Y>Re. The transfer factor of the elements for tomato fruit was determined to be in the range of 10⁻⁵–10⁻². The characteristic translocation behavior of the elements gives us fundamental information on the assessment of pollutant uptake by the tomato plant.