干旱胁迫对大豆鼓粒期叶片光合能力和根系生长的影响

以晋大70(抗旱型)和晋豆26(敏感型)2个大豆品种为材料,采用盆栽方法,在鼓粒期设置充分供水、轻度干旱和重度干旱3种水分处理,研究了干旱胁迫对大豆鼓粒期叶片光合能力和根系生长的影响.结果表明： 随着干旱程度加剧,2个品种的叶面积、叶绿素含量、净光合速率、叶片气孔导度、蒸腾速率、胞间CO₂浓度、株质量、株高、籽粒产量和收获指数均降低;根长和根质量在轻度干旱胁迫下增加,在重度干旱胁迫下减少;根冠比随干旱程度加剧而升高.重度干旱胁迫下,抗旱型品种晋大70根冠比的增幅达到135.7%,大于敏感型品种晋豆26根冠比的增幅(116.7%),晋大70的叶面积和叶绿素含量分别为对照的69.3%和85.5%,均优于晋豆26,晋大70的气孔导度和净光合速率分别下降了67.9%和77.9%,降幅均小于晋豆26,晋大70的收获指数的降幅为43.8%,小于晋豆26 (78.8%).不同干旱处理下,2个品种的叶面积、叶绿素含量、净光合速率、气孔导度、蒸腾速率、胞间CO₂浓度两两之间均呈显著正相关;株质量、株高、根长、根质量、籽粒产量、收获指数两两之间均呈显著正相关;根冠比与根质量呈显著正相关,而与其他5个指标呈显著负相关.     

外源褪黑素对干旱胁迫下大豆结荚期光合及生理的影响

以"绥农26"为供试大豆品种,采用盆栽方式,研究外施100μmol·L~(-1)褪黑素对干旱胁迫下大豆结荚期光合及生理的影响。结果表明:与正常供水相比,随时间延长,干旱胁迫处理大豆植株生长受到抑制,结荚数量减少,并最终造成产量降低,光合作用和叶绿素荧光不断降低,抗氧化酶活性和渗透调节物质则呈先上升后下降趋势,而膜脂过氧化水平则不断升高;外源褪黑素提高了干旱胁迫下大豆结荚期地上部和地下部鲜干重、株高、叶面积和结荚数量并提高产量,缓解光合及叶绿素荧光下降,增加大豆叶片抗氧化酶(SOD、POD、CAT、APX)活性和渗透调节物质(可溶性糖、可溶性蛋白、脯氨酸)含量,调节膜脂过氧化平衡(MDA、H2O2和相对电导率);褪黑素处理提高了干旱胁迫下大豆叶片Pn、Tr、Gs,分别提高14.1%～30. 0%、7. 3%～19. 6%、12. 4%～20. 3%,Fv/Fo、Fv/Fm、ΦPSⅡ和ETR分别提高3.5%～15.5%、5.4%～9.4%、2.6%～5.9%、3.0～18.2%;褪黑素处理籽粒鲜重、籽粒干重、籽粒数量、结荚数量和株高较干旱胁迫处理分别提高37.5%～51.4%、35.2%～150.0%、23.4%～42.1%、6.6%～28.7%、2.6%～9.6%,褪黑素处理单株荚数、单株粒数、单株粒重和百粒重较干旱胁迫处理分别提高8.6%、7.1%、10.5%和6.5%。综上所述,外源褪黑素可以提高干旱胁迫条件下光合和抗氧化酶活性并能缓解生长抑制,增强了大豆抵御干旱的能力并提高其产量。     

高浓度臭氧对大豆生长发育及产量的影响

采用开顶式同化箱(open-top chambers,OTCs)装置,设置活性碳过滤大气(CF,［O₃］<10 μg·kg^-1)和高臭氧(O₃)浓度(HO,约为80 μg·kg^-1)两个处理,研究开花后高浓度O₃对大豆农艺性状、叶面积、叶绿素、抗氧化系统与产量的影响.结果表明： 与对照(CF)同期相比,HO处理植株的叶面积和叶绿素含量显著降低(P<0.05);过氧化物酶、过氧化氢酶和超氧化物歧化酶活性极显著增强(P<0.01),但随着处理时间的延长,其活性逐渐降低;HO处理下植株叶片中可溶性蛋白质和抗坏血酸(AsA)含量降低,丙二醛含量显著升高,表明膜脂过氧化进程加快;大豆的单株干物质量、有效结荚数、籽粒数、百粒重和产量都有所降低,其中产量降低了47%,差异达极显著水平(P<0.01).     

臭氧浓度升高对香樟叶片光合色素及抗过氧化的影响及其氮素响应

为阐明氮(N)沉降条件下我国亚热带典型常绿树种香樟(Cinnamomum camphora)的臭氧(O3)胁迫响应特征,以1年生幼苗为试验对象,采用开顶气室(OTC)进行模拟研究。O3处理设大气O3(AA)、大气O3+60 nmol/mol(AA+60)、大气O3+120nmol/mol(AA+120)3个水平;N素以硝酸铵(NH4NO3)溶液形式施加,施N量设0(N0)、30(N30)、60(N60)(kg.hm-.2a-1)3个水平。主要考察了叶片膜质过氧化、光合色素、胞质抗坏血酸含量及总抗氧化能力的胁迫响应特征。结果表明:一个生长季(2009年5月15日—2009年9月10日)高浓度O3处理导致试验幼苗叶肉细胞膜脂过氧化程度显著加剧,叶绿素a、叶绿素b、类胡萝卜素含量显著降低;N素施加显著提高了叶绿素含量,但未改变细胞膜脂过氧化水平。叶片总抗氧化能力在AA+120处理下显著提高,但未受N施加影响。还原型抗坏血酸含量在N0处理下随O3浓度升高而降低;在N30及N60处理下随O3浓度升高而增高。施N可通过提高叶片抗坏血酸含量来增强香樟对O3升高的适应能力。研究结论可为O3与N复合污染下,我国亚热带地区典型常绿树种的保护提供科学参考。     

干旱胁迫下硅对玉米光合作用和保护酶的影响

利用盆栽试验研究了施硅（K₂SiO₃）对玉米植株抗旱能力的影响.结果表明：与对照相比,干旱胁迫下施硅提高了玉米植株的生物量积累,轻度和重度水分胁迫处理分别提高了31.1％～33.3％和23.7％～40.5％;施硅提高了玉米植株的净光合速率（10.9%～28.8%）和叶绿素含量（4.0%～11.9%）;施硅使干旱胁迫下玉米植株的POD、SOD和CAT活性分别提高6.4%～26.4%、17.8%～26.8%和3.2%～33.5%,抑制了干旱胁迫下叶片细胞膜透性的增加和丙二醛含量的升高.相关分析表明,干旱胁迫下玉米干生物量积累与日光合积累呈显著相关（r=0.9357,P<0.05）,说明光合作用的提高是干旱胁迫下硅对生物量积累影响的主要因素.较高的保护酶活性减轻了自由基的伤害作用,是硅增强植株抗旱性的另一重要因素.     

尾巨桉DH3229幼苗对硝普钠-酸铝互作的响应

该研究以广西林业科学研究院提供的尾巨桉DH3229幼苗为材料,以分析纯AlCl3·6H2O为铝(Al)的供体,以硝普钠(SNP)为一氧化氮(NO)的供体,设置3个SNP浓度(0、10、500μmol·L~(-1))和2个Al水平(0、5 mmol·L~(-1)),每5 d浇一次含不同浓度Al和SNP的营养液,持续20周,分析Al胁迫对幼苗生长生理特性的影响,并探讨不同浓度外源SNP施加对植物Al毒害有无缓解作用及其缓解机理。结果表明:Al施加能显著降低尾巨桉DH3229幼苗的生物量、叶片叶绿素a、总叶绿素含量、叶绿素a/b值和可溶性糖含量;Al胁迫显著增加幼苗相对电导率、MDA、SOD、游离脯氨酸含量。外源施加适量(10μmol·L~(-1))的SNP能使Al胁迫下桉树幼苗根和叶等生物量、叶片叶绿素含量以及Chl a/b显著提高,同时降低其相对电导率、MDA含量和游离脯氨酸含量。可见,SNP具有双重性,适量SNP施加可有效缓解Al对桉树生长的胁迫,高浓度(500μmol·L~(-1)) SNP则产生硝化胁迫从而抑制桉树的生长。     

镉胁迫对紫花苜蓿幼苗生理特性和镉富集的影响

以"甘农三号"紫花苜蓿幼苗为材料,在水培条件下,探究了在10 d内不同浓度(0～2.0 mmol·L^-1)镉(Cd)胁迫对其根长、茎长、生物量、叶绿素和丙二醛(MDA)含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、Cd富集及其亚细胞分布的影响。结果表明:低浓度(0.125 mmol·L^-1) Cd能促进幼苗根和茎的生长,增加叶片叶绿素含量,较高浓度(0.5～2.0 mmol·L^-1) Cd显著抑制幼苗根和茎的生长,叶绿素及生物量显著降低; Cd胁迫使MDA含量显著增加,而SOD和POD活性显著增强,其中Cd胁迫浓度为0.5mmol·L^-1时,SOD和POD活性达到最大值,这可能是植物对环境胁迫的一种应激保护反应; Cd在各亚细胞组分中的含量依次为细胞壁>细胞质>线粒体>叶绿体,且均随Cd胁迫浓度的升高而增加。当Cd胁迫浓度为0.125 mmol·L^-1时,水培10 d的紫花苜蓿幼苗单株地上部对Cd的净化率最高可达0.214%,而整盆植株在单位体积内对Cd的净化率最高可达15.5%;当Cd胁迫浓度为2.0 mmol·L^-1时,紫花苜蓿幼苗地上部Cd含量达89.36μg·g-1。这些结果表明紫花苜蓿对Cd具有很强的富集能力,虽未达到Cd超富集植物的临界标准,但从植株生物量、耐Cd能力、富集Cd量及对Cd的净化率等方面综合考虑,紫花苜蓿在Cd污染土壤的植物修复中具备良好的应用价值。     

O3浓度升高和UV-B辐射增强对大豆叶片叶绿素含量和活性氧代谢的影响

以大豆栽培品种铁丰29为试验材料,利用开顶式气室研究O₃浓度升高和UV B辐射增强复合胁迫对大豆叶片叶绿素(Chl)含量、膜脂过氧化程度、活性氧产生速率、抗氧化酶活性和籽粒产量的影响.结果表明： 在大豆整个生育期内,与对照相比,O₃和UV-B单一胁迫及其复合胁迫下的大豆叶片Chl(a+b)、Chl a和Chl b含量均呈下降趋势;相对电导率、丙二醛含量增大,活性氧产生速率和H₂O₂含量增加,超氧化物歧化酶、过氧化物酶和过氧化氢酶活性下降,产量降低.O₃和UV-B复合胁迫加剧了大豆叶片膜脂过氧化程度,促进大豆体内活性氧自由基的产生,使大豆抗氧化能力减弱,叶绿素含量降低,对大豆表现为协同效应.O₃胁迫对大豆叶片的影响与复合胁迫更相近,其原因可能是在复合胁迫中臭氧起主要作用.     

硅对铬胁迫下小白菜生理指标的影响

通过土培试验,研究了施硅对铬胁迫下小白菜(Brassica parichinensis)产量、叶绿素含量以及过氧化氢酶(CAT)和过氧化物酶(POD)的影响.结果表明:当土壤中未加铬(cr6 )时,随着硅浓度的增加,小白菜产量逐渐增加,叶绿素含量减少;在不同铬(Cr6 )处理的土壤中,施加0.5 g·kg-1 Na2SiO3可显著增加小白菜产量(P＜0.05);1.0 g·kg-1的硅可显著降低铬对小白菜叶片CAT和POD的活性,抑制铬对小白菜的毒害作用;硅浓度继续增加,其抑制效果开始降低.     

硅对受土壤中镉污染的白菜生长和抗胁迫能力的影响

在土培盆栽条件下,硅可提高白菜的地上部鲜重和茎鲜重,但根鲜重下降,叶鲜重略有下降。硅可抑制白菜吸收镉,在0.3、0.6、1.2mg·kg~(-1)镉水平下,施硅可显著降低白菜地上部的镉含量,并在一定程度上提高叶中过氧化物酶(POD)活性,但降低超氧化物歧化酶(SOD)活性。0.5、1.0 g·kg~(-1)硅可提高白菜的叶绿素含量和过氧化氢酶(CAT)活性,降低叶细胞膜透性,从而提高其对镉胁迫的耐受力。较高的硅浓度对植物有一定的毒性,叶绿素含量和CAT活性都下降,细胞膜透性也增加。     

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.     

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.     

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。     

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.     

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.     

医疗机构合理用药评价模型的构建研究

目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。     

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.