NaCl胁迫下海滨锦葵种子萌发和幼苗生长过程的生理特性变化

以1／4 Hoagland溶液为基础培养液,研究了0．5％、1．0%、1．5％、2．0％和2．5％NaCl处理对海滨锦葵[Kostelezkya rirginica（L．）Presl．]种子萌发和幼苗生长的影响,发现随着培养液中NaCl浓度的增加,海滨锦葵种子萌发率逐渐降低;当NaCl浓度达2．5％时种子不萌发,但NaCl胁迫解除后,种子的萌发率水平与对照相当。幼苗在含0．5％～1．0%NaCl的培养液中生长状况良好,叶绿素含量和根系活力明显增高;但当NaCl浓度达1．5％-2．0％时,叶绿素含量和根系活力逐渐下降;与对照相比,NaCl胁迫下幼苗的MDA水平降低。结果表明,NaCl胁迫对海滨锦葵种子萌发和幼苗牛长有一定的影响,但海滨锦葵可通过种子休眠、增加根系活力、降低体内MDA水平来缓解一定的盐害效应．以适应盐胁迫的生长环境．     

外源多胺对盐胁迫下玉米叶绿体结合态多胺水平和光合作用的影响

在100 mm o l/L N aC l胁迫下,研究了外源多胺-腐胺(Pu t)、尸胺(C ad)、亚精胺(Spd)和精胺(Spm)对玉米幼苗生长、光合速率和PSⅡ光化学效率(Fv/Fm)、叶绿体结合多胺和叶片丙二醛(M DA)含量以及抗氧化酶活性的影响.结果表明,叶面喷施1 mm o l/L的Pu t、Spd和Spm可显著增加盐胁迫下玉米幼苗干物质重、叶绿体内结合态多胺的含量、叶片净光合速率和PSⅡ光化学效率(Fv/Fm),并降低了叶片中M DA含量.外源Spd和Spm明显增加盐胁迫下玉米幼苗的抗坏血酸过氧化物酶(APX)、过氧化物酶(POD)和过氧化氢酶(CAT)活性;外源Pu t可增强APX和POD活性,对CAT活性的影响不明显.这些结果表明多胺对玉米盐害的缓解作用可能是由于提高了叶绿体中结合态多胺的含量和叶片抗氧化酶的活性,从而增强了盐胁迫下的玉米光合能力.     

碱胁迫对菊芋幼苗生长及其光合作用和抗氧化作用的影响

采用砂培试验研究了碱胁迫(0、12.5、25.0、37.5和50.0 mm o l.L-1N a2CO3)对2种菊芋(H elianthustuberosus L.)南芋8号(H t 1)和南芋1号(H t 2)幼苗生长及其光合作用和抗氧化作用的影响。结果表明,2种菊芋耐碱的极限浓度为50.0 mm o l.L-1;碱胁迫,尤其是高浓度(37.5 mm o l.L-1)的胁迫,显著降低菊芋幼苗总鲜重、净光合速率(Pn)、气孔导度(G s)、蒸腾速率(T r)、水分利用效率(WUE)及叶绿素总量(Ch l a Ch l b)、类胡萝卜素(C aro)含量与叶片和根POD活性,而显著提高细胞间隙CO2浓度(C i)、叶片和根SOD活性以及丙二醛(M DA)含量。此外,H t 1叶绿素a/b(Ch l a/Ch l b)在碱胁迫下没有明显变化,而H t 2却明显降低。这些结果表明非气孔限制是碱胁迫下2种菊芋幼苗Pn降低的主要原因。菊芋品种H t 1幼苗耐碱能力大于菊芋品种H t 2,这可能与H t 1碱胁迫下维持了较高的Pn、G s、T r、WUE、Ch l a/Ch l b、C aro含量、SOD和POD活性和较低的M DA含量有关。     

发菜细胞培养物对盐胁迫的响应

用不同浓度(0、0.1、0.2、0.4 m o l.L-1)的N aC l处理BG 110培养的发菜细胞,结果显示,发菜光合速率与叶绿素荧光强度随N aC l浓度的升高先增加后降低,当N aC l浓度为0.1 m o l.L-1时光合速率与叶绿素荧光具有最大值,表明发菜细胞培养物能耐受一定浓度的盐胁迫.以BG 110+0.4 m o l.L-1N aC l为对照,在BG 11+0.4m o l.L-1N aC l的胁迫实验中,光合速率与叶绿素荧光强度下降较慢;丙二醛、脯氨酸含量较低;类胡萝卜素含量较高,表明在培养液中添加外源硝酸盐后可以缓解N aC l对发菜细胞培养物的生理胁迫效应,增强其抗盐性.     

海滨锦葵萌发期和苗期盐胁迫反应及耐盐性鉴定指标筛选

选用海滨锦葵自然群体为研究材料,以Na Cl溶液为盐胁迫,研究海滨锦葵在不同浓度盐胁迫下萌发期和幼苗期生长状况的变化,并筛选萌发期和幼苗期耐盐鉴定指标。结果表明,Na Cl胁迫下海滨锦葵种子发芽率、发芽势、发芽指数、下胚轴长、胚根长、鲜重、活力指数及幼苗株高均降低,并且各指标的盐害系数随着盐胁迫浓度的升高而升高。较低Na Cl浓度(0.5%~1.5%)胁迫下的幼苗地上干重和地上鲜重高于未用Na Cl胁迫的幼苗,2.0%和2.5%浓度的Na Cl胁迫抑制了地上干重和地上鲜重。1.0%和2.0%的Na Cl浓度分别是萌发期和幼苗期鉴定海滨锦葵耐盐性的适宜浓度,发芽率、发芽势、发芽指数、下胚轴长、根长、鲜重以及活力指数可以作为萌发期耐盐性的鉴定指标,株高、地上鲜重和地上干重可以作为幼苗期耐盐性的鉴定指标。     

壳聚糖对黄瓜幼苗抗盐的协同生理作用研究

在200 mm o l.L-1N aC l胁迫条件下,采用根部注射结合叶面喷施的方法,研究了不同浓度(0、50、100、150、200、250 m g.L-1)壳聚糖(Ch itosan,CTS)对黄瓜(Cucum is sa tivus L.)幼苗抗盐的生理作用。结果表明:CTS能够显著促进黄瓜幼苗的生长,降低植株盐害指数,最高幅度达36.2%(P<0.01);显著提高幼苗叶片游离脯氨酸(P ro)含量、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)等抗氧化酶活性(P<0.01);有效降低叶片细胞脂质过氧化产物丙二醛(M DA)含量和电解质渗透率(P<0.01);筛选出CTS最佳处理浓度为150 m g.L-1,持效期8 d以上。研究表明适宜浓度的CTS具有增强活性氧清除能力、保护生物膜功能、提高黄瓜幼苗抗盐的协同生理作用。     

外源褪黑素对复合盐碱胁迫下黑果枸杞种子萌发和幼苗生长的缓解效应

以黑果枸杞种子为实验试材,将中性盐NaCl、Na₂SO₄和碱性盐NaHCO₃、Na₂CO₃按碱性盐占比由小到大模拟组成中性复合盐L(1∶1∶0∶0)、中度碱性复合盐M(1∶9∶9∶1)和重度碱性复合盐H(9∶1∶1∶9),采用纸上萌发法,研究外源褪黑素浓度(0.1、0.3、0.5、1.0 mmol/L)对不同盐碱组成(L、M、H)及其盐碱浓度(50、100、200 mmol/L)组合胁迫下黑果枸杞种子萌发和幼苗生长的影响。结果显示：(1)黑果枸杞幼苗的生长表型(长势)随盐碱浓度及碱性盐占比升高明显减弱;适当低中浓度外源褪黑素(0.1、0.3、0.5 mmol/L)能在一定程度上缓解盐碱胁迫对幼苗生长的伤害,过高浓度外源褪黑素(1.0 mmol/L)则使伤害加剧;施加外源褪黑素使黑果枸杞幼苗侧根数量明显增多。(2)黑果枸杞种子的萌发进程与盐碱组成、盐碱浓度及褪黑素浓度密切相关,随盐碱浓度和碱性盐占比升高,黑果枸杞种子萌发的起始时间延迟,萌发总时长缩短;施加适当浓度外源褪黑素能使盐碱胁迫下黑果枸杞种子萌发起始时间提前,并延长萌发总时长。(3)在L复合盐处理中,随盐碱胁迫浓度升高,黑果枸杞种子的发芽率(GR)、发芽势(GP)、发芽指数(GI)、活力指数(VI)、芽长(SL)、根长(RL)均先升后降,但在M和H复合盐碱处理中,各项萌发指标均随盐碱胁迫浓度升高呈逐渐下降趋势。(4) 外源褪黑素对黑果枸杞种子各项萌发指标具有明显“低促高抑”现象,L复合盐中,在3种盐碱浓度胁迫下,褪黑素浓度为0.1和0.3 mmol/L时对GP、GR、GI、VI、SL、RL有促进作用,并以0.1 mmol/L综合促进效果最佳,褪黑素浓度为0.5和1.0 mmol/L时对GP、GR、GI、VI产生抑制作用,褪黑素浓度为1.0 mmol/L对SL、RL有抑制作用;M和H复合盐中,在3种盐碱浓度胁迫下,褪黑素浓度为0.1、0.3、0.5 mmol/L时对各指标均有促进作用,并以0.3 mmol/L综合促进效果最佳,褪黑素浓度为1.0 mmol/L时则产生抑制。研究表明,低浓度中性复合盐处理对黑果枸杞种子萌发和幼苗生长有一定促进作用,高浓度中性复合盐及中度和重度碱性复合盐则产生抑制作用;外源褪黑素对盐碱胁迫下黑果枸杞种子萌发和幼苗生长的缓解具有明显剂量效应,0.1 mmol/L褪黑素对中性复合盐胁迫的综合促进效果更佳, 0.3 mmol/L褪黑素则对中度和重度碱性复合盐胁迫有最佳促进效果。     

盐胁迫及外源钙处理对盐肤木种子萌发的影响

为研究盐肤木种子萌发的盐胁迫机制和外源钙对盐胁迫下种子萌发的影响,实施不同浓度的NaCl、Na_2SO_4、CaCl_2+NaCl、CaCl_2+Na_2SO_4溶液胁迫处理盐肤木(Rhus chinensis)种子的萌发试验,分析其发芽指标、活力参数和幼苗生长的变化。结果表明:随着盐胁迫溶液NaCl和Na_2SO_4浓度的升高,盐肤木种子的发芽率、发芽势、发芽指数、活力指数和幼苗胚芽及胚根长均表现为不同程度减少的趋势,其中100 mmol/L NaCl、75 mmol/L Na_2SO_4胁迫对盐肤木种子的萌发及幼苗的生长有显著的抑制作用;同胁迫溶液NaCl相比,盐肤木种子萌发过程中对Na_2SO_4危害敏感的浓度范围较小。不同浓度的CaCl_2浸种处理时,盐肤木的盐害缓解作用呈现先升高后降低的趋势,30 mmol/L CaCl_2+100 mmol/L Na Cl和15 mmol/L CaCl_2+75 mmol/L Na_2SO_4浓度下盐胁迫处理的缓解能力最强。该研究结果有利于缓解盐胁迫对于盐肤木种子萌发的盐害。     

NaCl胁迫对黄瓜幼苗植株生长和光合特性的影响

采用营养液水培法,选用耐盐性不同的2个黄瓜品种,研究了不同浓度N aC l处理对黄瓜幼苗植株生长及叶片光合特性的影响。结果表明,在盐胁迫下,净光合速率(Pn)呈下降趋势,气孔导度(G s)变化趋势与Pn相一致;气孔限制值(L s)在处理的前4 d显著升高,随处理时间延长而下降;细胞间隙CO2浓度(C i)的变化趋势与L s相反;光合碳同化的量子效率(Φc)明显下降。耐盐性较弱的‘津春2号’各项光合参数变化幅度明显大于耐盐性较强的‘长春密刺’。短期N aC l处理,Pn下降以气孔限制因素为主,较长期N aC l处理,Pn下降转向非气孔限制因素。     

CdCl2对豌豆种子萌发和幼苗生长的影响

以豌豆为实验材料,采用水培方法研究了Cd2 单盐胁迫对豌豆种子萌发与生长的影响。结果显示:(1)Cd2 质量浓度≤1 mg/L时,促进种子萌发,Cd2 质量浓度达到5 mg/L时抑制种子的萌发。(2)随Cd2 质量浓度的增加Cd2 对幼苗根生长的抑制作用逐渐增强;Cd2 质量浓度≤5 mg/L时,促进茎的生长,≥10 mg/L时,抑制茎的生长;且Cd2 对幼苗根生长的抑制作用大于茎。(3)低浓度Cd2 能促进幼苗叶绿素合成,当Cd2 质量浓度高于1 mg/L时,则对幼苗叶绿素合成有抑制作用,且随Cd2 质量浓度增加叶绿素含量逐渐下降。(4)Cd2 诱发的胚根细胞核、染色体畸变率随着Cd2 质量浓度增加而增大。(5)过氧化物酶(POD)同工酶的活性随着Cd2 质量浓度升高而明显增强,Cd2 质量浓度为1 mg/L时POD活性最强,但当Cd2 质量浓度达10 mg/L时,POD的灰度值明显下降。     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

The effects of glutamine of the maintenance of embryogenic cultures of Cryptomeria japonica

Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l⁻¹ glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l⁻¹) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.     

Specificity of action of piperidylcholine derivatives as substrates of cholinesterases of various origin

The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.