高温诱导黄瓜抗霜霉病机理

研究了高温对黄瓜霜霉病菌致病力的影响以及高温控制霜霉病发生的效果.结果表明,40 ℃高温处理2 h和45 ℃处理1 h对黄瓜霜霉病的诱导抗病性作用最明显,其在接种后4 d时的防效分别为58.40%和45.81%,到接种后6 d时,防效分别下降为39.35%和37.65%.经高温诱导后,过氧化物酶（POD）、苯丙氨酸解氨酶(PAL)、几丁质酶（Cht）、β-1,3-葡聚糖酶（Glu）活性均显著高于对照,与未诱导植株相比,高温诱导后叶片组织的细胞壁表面有大量木质素沉积,表明高温处理后黄瓜表现出对霜霉病的抗病性.     

黄瓜霜霉病菌侵染若干因子的研究

研究了温、湿度条件对黄瓜霜霉病菌致病性的影响,结果表明,25～35℃最适宜黄瓜霜霉病的发生,15/35℃的交替温度变化最有利于霜霉病菌的侵染,但35℃以上的高温对霜霉病菌具有杀伤作用;2 h的湿度条件就足以引起侵染,一旦侵入寄主,环境湿度条件对病害的发展影响不大.-20℃低温冷冻保存10个月和干燥放置7 d的霜霉菌种仍具致病力.发病的黄瓜叶片可以连续产生孢子囊,但随着发病时间的延长产生孢子囊量逐渐减少.活体叶片单位面积上产生的孢子囊量比离体叶片大,且显症天数与叶片单位面积产生孢囊量呈抛物线型关系.     

高温处理防治黄瓜霜霉病的生理生化机制

以黄瓜感病品种‘长春密刺’为试材,通过室内盆栽试验研究高温对已感染霜霉病菌的黄瓜幼苗生理生化特征的影响.结果显示:(1)在黄瓜幼苗接种霜霉菌后8h,用45℃高温处理90min防治效果最明显.(2)与只接种霜霉病菌的黄瓜幼苗相比,接种霜霉菌后进行高温处理可显著提高叶片叶绿素含量,降低丙二醛含量;与对照相比,接种霜霉菌后进行高温处理可显著提高叶片几丁质酶活性,Western blotting验证了几丁质酶的活性变化.(3)SDS-PAGE结果表明,霜霉菌侵染可诱导一种28kD蛋白表达,高温处理后28kD蛋白的表达量降低.研究结果表明高温处理可能在杀死病原菌的同时,还诱导黄瓜幼苗对霜霉病产生了部分抗性.     

番茄高温高湿胁迫后的补偿生长

为了解高温高湿复合胁迫对番茄的影响,以番茄品种"金冠五号"(Jinguan 5)为对象,设计温度、相对湿度和处理天数三因素正交试验,温度设置4个水平(昼温/夜温),即32℃/22℃、35℃/25℃、38℃/28℃、41℃/31℃,相对湿度设置3个水平,为50%±5%、70%±5%、90%±5%,持续时间设为4个水平,为3、6、9、12 d。以28/18℃、50%～55%环境下处理的番茄幼苗为对照组(CK)。分别在高温高湿胁迫后及恢复生长的7、14、21、28 d进行取样,测定生长指标、抗氧化酶活性及叶绿素含量。结果表明:高温胁迫后,35、38、41℃处理下番茄干重显著降低,叶面积显著增加,41℃番茄干重较CK降低12.89%,高温处理后叶绿素a、叶绿素b、类胡萝卜素含量低于CK,SOD、POD、CAT酶活性均高于CK,且随温度升高,酶活性呈先上升后下降的趋势,38℃处理SOD、POD、CAT酶活性最高,分别较CK增加121.14%、35.41%、55.13%;从湿度来看,相同高温条件下,RH70%处理番茄的生长最好,RH70%处理番茄SOD、POD、CAT酶活性、叶绿素含量显著高于RH50%和RH90%湿度处理;适当的高温能够促进番茄的生长,增加抗氧化酶活性,32℃以下番茄生长呈超补偿;38℃及其以上番茄生长严重受阻;高温条件下,增加湿度能够一定程度上缓解高温对植株的胁迫,但这种作用也是有限的,并不能够完全抵消高温胁迫的伤害。     

飞虱虫疠霉继发性感染对桃蚜数量增长的控制作用

用飞虱虫疠霉（Pandora delphaics)“孢子浴”接种的桃蚜(Myzus persicae)无翅成蚜在离体甘蓝菜叶片（65cm^2)上建立蚜群,在不同温度（10－30℃）和湿度（74％－100％RH）的组合条件下任其繁衍,发病和交互感染,以评价该菌的控蚜效果。在25个温,湿度组合处理（8次重复,每重复含3头接种成蚜)中,蚜群均不同程度的发病死亡,在历时30d的观察中,以高温（20－30℃）,高湿（95％RH）组合条件下的蚜群发病快且死亡率高,蚜尸上产生的孢子有效地引起若蚜继发性感染。与相同温度下不带菌的对照蚜群相比,次于30℃下,各湿度除个别例外,第8d的控蚜率达30％以上,第20d达80％以上。在10℃和15℃下,控蚜效果一般不如上述较高温度下,且与湿度的关联程度相对较低,但最大控蚜效果均发生在100％RH处理中。结果表明,飞虱虫疠霉用于蚜虫防治的潜力很大,值得深入研究和开发利用。     

不同温湿条件下贮藏的3种禾本科植物花粉的一些生理变化

测定了水稻、玉米和狼尾草花粉在低温(4℃),低湿(RH45％),低温(4℃)高湿(RH90％),高温(35℃),低湿(RH45％)和高温(35℃),高湿(RH90％)4种贮藏条件下的蛋白酶活性,蛋白质含量,游离氨基酸含量的变化,结果表明：在低温高湿条件下,蛋白质降解和游离氨基酸含量上升慢;在高温条件下蛋白质降解快,游离氨基酸含量迅速上升。3种植物花粉中,水稻花粉蛋白酶活性强,在贮藏过程中蛋白质降解速率和游离氨基酸含量上升快：狼尾草花粉蛋白酶活性低,在贮藏过程中蛋白质降解速率和游离氨基酸含量上升慢;玉米花粉的蛋白酶活性、蛋白质降解速率和游离氨基酸含量上升速率居两者之间。     

亚精胺诱导黄瓜幼苗对白粉病抗性的研究

以黄瓜品种‘长春密刺’幼苗为材料,研究了亚精氨(Spd)诱导黄瓜幼苗对白粉病的抗性,并测定Spd处理和白粉菌接种对黄瓜叶片4种防御酶活性及3种防卫基因表达的影响。结果显示:(1)0.2～1.0mmol.L-1 Spd对黄瓜幼苗白粉病抗性均有不同程度的诱抗效果,并以0.8mmol.L-1 Spd处理效果最明显,诱导效率可达55.3%。(2)喷施Spd或接种白粉菌均可提高黄瓜叶片过氧化物酶(POD)、苯丙氨酸解氨酶(PAL)、几丁质酶和β-1,3-葡聚糖酶的活性,且诱导并接种处理的植株叶片上述酶活性均比只诱导不接种处理的上升速度更快;同时,Spd处理和接种白粉菌可以提高植株叶片中POX、PAL、PR-1a基因的表达量。研究表明,Spd处理可以诱导防卫基因表达的增强,提高防御酶活性,显著降低病情指数,增强黄瓜幼苗对白粉病的抗性。     

大棚黄瓜霜霉病生态防治方法研究——温度控制试验研究初报

黄瓜霜霉病是对黄瓜生长发育危害最大的世界性病害。通过两年共10个处理的田间对比试验发现,大棚黄瓜霜霉病的发生发展与环境温度条件存在着十分密切的关系,在一定温度范围内(15℃—48℃),棚内日最高气温越高,发病期越晚,病越轻,产量越高。控制方法是:在大棚内日最低气温稳定大于10℃后,每隔一天对大棚进行一次40—47℃、并维持2小时左右的高温处理(其中大于42℃持续1.5小时左右,大于45℃持续1小时左右),然后大面积通风换气。方法简便易行、效果很好。     

苗期高温处理对黄瓜衰老和性别分化及激素含量的影响

黄瓜品系新泰密刺、EP－6、XC-1苗期高温处理后植株衰老进程加,给花分化受抑,3个品系中EP－6雌花分化对高温不敏感,XC－1高温下较抗衰老。茎中精胺含量较低和乙烯释放量较高的植株衰老进程加速,腐胺和GA3含量较高的植株雄花分化加快。     

高温对粘虫Leucania separata Walker发育与生殖的作用——Ⅰ.卵的发育与孵化

本文报导了几种相对湿度下25—46℃高温对粘虫卵发育与孵化的作用。卵发育及孵化的适温上限为31.0-32.5℃,其致死高温限为32.0-33.5℃。在25.0—32.0℃间,孵化率不因温度而有显著变化,发育速率则随温度升高而加快:湿度仅在大幅度下降时才对孵化率有显著影响,但对发育速率的影响则随温度增高而加大,在接近适温上限时湿度又成为决定卵发育与孵化的主要因素。高温的致死作用,因温度强度、处理时间及相对湿度而异。温度越高,忍受时间越短,41℃以上高温处理2小时,即使绝大部分卵死亡。高温下饱和湿度,对卵的发育与孵化不利。受精卵处于第一步分裂前期,抗高温能力较差。温度驯化略可提高卵的耐高温能力。文中还讨论了高温致死的原因及湿度的作用。     

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.