淹水胁迫下对烟草、油菜某些生理指标的比较研究

在淹水胁迫下,对烟草、油菜叶片光呼吸酶乙醇酸氧化酶（GO）,羟基丙酮酸还原酶（HPR）,过氧化氢酶（CAT）,呼吸速率,超氧化物歧化酶（SOD）及丙二醛（MDA）含量进行了研究,实验结果表明：淹水胁迫下,烟草,油菜叶片光呼吸途径中HPR,GO,CAT酶活性升高,呼吸作用加强,并且耐淹能力强的油菜品种中油821增加幅度大于耐淹能力弱的烟草品种SRI,淹水胁迫使植物体内SOD活性升高,但在淹水胁迫后期,油菜体内SOD活性开始下降,淹水胁迫下,烟草,油菜叶片中MDA含量升高。     

淹水胁迫下北美鹅掌楸无性系生理生化响应差异

北美鹅掌楸(Liriodendron tulipifera)是优良用材和绿化树种,但极不耐涝,阻碍了其广泛应用。本研究以前期试验筛选出的3个耐淹无性系(T4、T27和T37)和3个不耐淹无性系(S5、S9和S20)为实验材料,开展温室盆栽模拟淹水胁迫实验,通过比较丙二醛(MDA)含量、相对电导率(EL)、叶绿素含量,以及酶活性等生理生化指标的差异,探索不同无性系对淹水胁迫的响应和抗性差异。结果显示:北美鹅掌楸对淹水胁迫反应敏感,淹水4d时,耐淹无性系和敏感无性系均呈现下部老叶黄花,上部嫩叶、顶芽萎蔫现象,叶绿素含量减少,MDA、EL显著增加,超氧化物歧化酶(SOD)和过氧化物酶(POD)等酶活性极显著增加。淹水6 d后,敏感无性系受到的胁迫伤害进一步加剧,叶片萎蔫脱落,MDA、EL持续增加,叶绿素含量极显著降低,SOD和POD总体呈下降趋势;而耐淹无性系顶芽缓慢恢复,在叶片脱落后幼叶展开,叶绿素含量下降幅度较小,MDA和EL缓慢下降,SOD和POD持续升高,淹水20 d左右近水面的茎端形成不定根和大量膨大皮孔。研究表明:耐淹型北美鹅掌楸可通过形成不定根和肥大的皮孔、保持较高的抗氧化酶活性等方式增强其抗涝能力;EL、叶绿素含量、SOD活性可作为北美鹅掌楸耐淹无性系中期选育指标。     

外源调节剂对淹涝水稻幼苗株高及碳水化合物消耗的影响

为研究淹涝条件下水稻幼苗株高及碳水化合物消耗对不同外源生长调节剂的响应,本试验选用籼型常规稻IR64和导入耐淹涝基因Sub1的IR64-Sub1为试验材料,秧龄20 d时喷施1-氨基环丙烷-1-羧酸(ACC)、多效唑(PB)、赤霉素(GA)3种外源生长调节剂,以喷施清水为对照(CK).喷施处理2 d后进行0、4、8、12、16 d没顶淹涝胁迫,淹涝胁迫结束后常温恢复7 d,取样分析不同外源生长调节剂对水稻成活率、株高、叶绿素降解及恢复、地上部非结构性碳水化合物(NSC)消耗的影响.结果表明:淹涝导致水稻幼苗株高显著增长,叶片SPAD值快速下降,叶片可溶性糖迅速消耗,但耐淹涝品种IR64-Sub1淹水前茎鞘NSC含量明显高于IR64,淹涝中NSC消耗速率低于IR64,淹水结束后地上部淀粉含量高于IR64.外源PB处理显著抑制水稻幼苗株高增长、叶绿素降解及NSC消耗,提高存活率,且对IR64-Sub1效果更为显著.外源GA处理水稻幼苗叶绿素降解、株高增长和NSC消耗最快,植株恢复能力最低,耐淹涝能力最差,但与IR64相比,GA对IR64-Sub1淹涝耐性的抑制明显减弱.外源ACC促进伸长效果明显低于外源GA处理.淹水前喷施PB可有效抑制植株水下伸长,延缓叶绿素降解,减缓NSC消耗,保留更多NSC,为淹水胁迫解除后水稻快速恢复提供有利条件,这对于易涝地区减轻涝渍危害具有重要意义.     

水稻的耐淹性状及其Sub1基因

近4年来, 水稻(Oryza sativa L.)耐淹性状及其分子机理的研究取得了长足的进展。水稻植株的耐淹性状主要由Submergence-1 (Sub1) 基因控制。Sub1通过调节乙烯和赤霉素介导的反应, 抑制淹水期间的伸长生长和减缓碳水化合物消耗来控制耐淹性状。文章介绍了水稻应对淹涝胁迫的两种策略, 影响耐淹性状的主要生理因素, Sub1基因定位以及它控制耐淹性状的机理; 阐述了Sub1基因在我国杂交水稻生产方面的应用前景。     

拔节期淹涝胁迫对水稻形态和产量构成因素的影响

以常规稻湘早籼45为供试材料,在拔节期设计不同淹水深度(2/3淹和全淹)及淹水持续时间(3、5、7和9 d)的淹涝胁迫试验,分析不同淹涝胁迫处理对水稻绿叶数、卷叶长度、叶鞘长度、高位分蘖等形态因子以及产量构成因子的影响。结果表明:不同淹水深度处理,绿叶数与淹水持续时间呈负相关,且2/3淹较全淹更明显;全淹处理,茎变化明显;2/3淹处理,叶变化明显;高位分蘖率与淹水持续时间呈正相关;卷叶长度变化,在2/3淹时,与淹水持续时间呈负相关,全淹时,两者呈正相关;叶鞘的变化,不同处理之间差异不大,均表现为伸长生长。不同淹涝胁迫处理对产量构成因子的影响均表现为空壳率高、穗结实粒数低和千粒重低,2/3淹持续9 d处理的影响最大,结实粒数最低,仅有34粒。探讨了不同淹涝胁迫环境,水稻茎、叶等形态特征变化的适应机制和可能原因。研究结果可为长江中下游地区水稻洪涝灾害防灾减灾以及抗灾品种选育提供科学依据。     

淹涝胁迫对鹅掌楸属植物叶片部分生理指标的影响

研究了淹涝胁迫对不同种源鹅掌楸[Liriodendron chinense（Hemsl．）Sarg．]和杂种鹅掌楸（L．chinense xL．tulipifera）幼苗部分生理指标的影响。结果表明：在淹水处理24h后,杂种鹅掌楸幼苗叶片的净光合速率变化不明显,鹅掌楸幼苗叶片的净光合速率则有一定程度的下降;在淹水处理48h后,净光合速率均大幅度下降。在淹涝胁迫下及胁迫解除后,幼苗叶片叶绿素含量持续缓慢下降;而脯氨酸含量总体上呈现上升的趋势;与鹅掌楸相比,杂种鹅掌楸幼苗的超氧化物歧化酶（SOD）和过氧化物酶（POD）活性变化不明显,但SOD活性最高,POD活性最低。结果表明,杂种鹅掌楸具有较强的耐淹涝胁迫的能力。     

水稻耐淹涝性状的遗传分析和SSR标记的研究

淹涝胁迫对水稻生产造成了严重影响, 发掘可应用于耐淹涝辅助选择的分子标记(MAS), 将有助于水稻耐淹涝性状的遗传改良。应用耐淹涝材料FR13A和淹涝敏感材料IR39595-503-2-1-2为亲本做正反交获得F₁和F₂代群体。对正反交的F₁群体的耐淹涝性状进行遗传分析, 发现正反交的F₁代群体在耐淹涝性状上没有显著差异, 说明耐淹涝性状是核基因控制。从两次淹涝处理中F₂代群体的分离情况来看, 来源于FR13A的耐淹特性表现出数量-质量性状遗传的特点。当淹涝胁迫压力比较轻时表现为数量性状遗传, 具有微效多基因的作用。当淹涝胁迫压力增大时, 表现为主效基因控制的质量性状。在SSR分析中, 187对SSR引物中有73对引物在两亲本间有明显的差异, 差异率为39%。用这73对差异引物, 对F2群体进行多态筛选, 结果筛选到一个与耐淹涝性状连锁的标记RM219, 验证了耐淹涝性状确实由主效基因Sub1控制, 因此, RM219在水稻耐淹涝育种中具有利用价值。     

淹涝胁迫对水稻叶鞘和叶片中淀粉粒分布的影响

淹涝是世界上当前所面临的最严重自然灾害之一,尤其是近几年来,淹涝给我国的农业生产带来了巨大损失,全国平均每年受涝面积814万hm2,其中成灾面积448万hm2,损失粮食约28亿kg〔1〕。水稻是我国的主要粮食作物,并且分布于淹涝易发生的南方多雨潮湿地区和北方低洼地带,淹涝对水稻产量影响极大,因此,研究淹涝胁迫对水稻的伤害及水稻的耐淹机制越来越受到人们的重视〔2〕。淹涝对植物的伤害并非是因为水分过多而造成的直接伤害,而是由于淹涝造成的次生胁迫,其中最严重的是缺氧。在缺氧条件下,细胞中的碳水化合物代谢途径改变,对植物的生长和发育…     

不同水稻品种对稻纵卷叶螟生长发育、存活、生殖及飞行能力的影响

系统研究了稻纵卷叶螟在6种不同水稻品种(常规粳稻武育粳3号,杂交粳稻宁粳1号,常规籼稻TN1,杂交籼稻汕优63,超级杂交籼稻两优培九,超级杂交籼粳稻甬优9号)上取食后的发育历期、存活率、卵巢发育进度、繁殖力和飞行能力.结果表明,武育粳3号和宁粳1号能显著延长稻纵卷叶螟未成熟期的发育历期,降低其存活率,延缓卵巢发育进度,降低成虫繁殖率,并提高成虫的飞行能力;不同水稻品种间的影响存在显著差异,其影响从大到小排列为杂交粳稻＞常规粳稻＞常规籼稻＞杂交籼稻＞超级杂交稻.这说明,幼虫期营养对稻纵卷叶螟的生长发育、存活、生殖和飞行能力具有显著影响.     

不同花生品种对旱涝胁迫的响应及生理机制

为评价花生对旱、涝胁迫的响应,本试验以4个旱、涝耐性差异明显的花生品种为材料,运用温室防雨盆栽方法,在苗期、花针期分别进行正常灌溉(对照)、干旱(7d,叶片萎蔫)、根部淹涝(土面水深2 cm,时间1d、3d、7d)和整株淹涝(水深至苗顶,时间1d、3d、7d)的处理,测定地上部及根系生物量、根冠比、根系活力、叶片超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量。结果表明,苗期、花针期干旱均抑制地上部生长,提高根冠比;苗期干旱降低根系生物量,而花针期增加。2个时期淹涝均促进地上部生长、抑制根系生长、降低根冠比,并随淹水加深、延时而加重。旱、涝条件下根系活力均降低,SOD、MDA呈上升趋势。遭受相同时间(7d)的水分胁迫后,危害程度以干旱重于淹涝,花针期重于苗期。基于生物量、生理指标变化的综合分析进一步表明,4个花生品种的旱、涝耐性差异很大,湘花55号耐旱性强、耐涝性弱,豫花15号耐旱性弱、耐涝性强,中花4号耐旱、涝性均最弱,中花8号耐旱、涝性均最强。     

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.     

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.     

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。     

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.     

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.     

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.