银杏种子脱水敏感性的研究

【目的】研究银杏种子脱水敏感性及相关的生理生化变化,为银杏种子贮藏、种质资源的保存及苗木生产提供理论依据。【方法】银杏种子于25 ℃、湿度(25±2)%条件下脱水67 d,种子含水量每下降5%左右时随机取样测定相关生理生化指标。【结果】当种子含水量降至45.1%时,发芽率并未有明显变化,然而,当种子含水量降至40.1%时,发芽率从开始的92%下降至50%;相关性分析表明种子含水量与发芽率之间存在极显著的正相关(r=0.910)。银杏种子脱水过程中,其相对电导率不断上升。此外,SOD活性变化与POD活性的变化基本相似,均呈现出先下降,后升高至最大值,再下降的趋势,只是其POD活性的上升比SOD早,说明POD的反应比SOD更为敏感。种子含水量与硫代巴比妥酸反应产物(TBARS)含量(r=-0.619)、相对电导率(r=-0.745)之间存在极显著的负相关关系。【结论】银杏种子对脱水高度敏感,表现出顽拗型种子特点。严重脱水降低了银杏种子抗氧化酶活性,并加剧了膜脂过氧化作用,导致种子活力下降乃至完全丧失。     

贮藏方法对大米草(Spartina anglica Hubbard)种子萌发的影响

同一贮藏期的大米草种子,不论室温干藏或低温湿藏,在蒸馏水中的萌发速度均优于在海水中萌发速度。室温干藏的,随着采收后贮藏时间的延长,发芽率下降,贮藏两个月后完全丧失了发芽率。低温(5℃)湿藏的,随着贮藏时间的延长,种子发芽速度加快。低温(5℃)干藏的种子,发芽率明显下降。以100ppm、200ppm、400ppm和800ppm赤霉素溶液浸泡种子24小时,对种子萌发具有一定的影响。     

不同处理对赤苍藤种子萌发和幼苗生长的影响

为研究不同因素对药食两用植物赤苍藤(Erythropalum scandens Bl.)种子萌发和幼苗生长的影响,本研究以当年采收的赤苍藤种子为材料,探讨浸种时间(0 d、1 d、2 d、3 d、4 d、5 d)、基质含水量(70%、50%、30%)、播种深度(0 cm、1 cm、3 cm、5 cm)、光照条件(全黑、自然光)、基质(沙土、肥土、黄土、混合土)、赤霉素浸种处理及破壳处理(全破、少破、不破)下赤苍藤种子的发芽率及幼苗特性,为其规模化发展提供理论参考。结果表明,浸种时间、基质含水量、播种深度、赤霉素处理均对发芽率有极显著影响(P<0.01),基质和破壳处理对发芽率有显著影响(P<0.05),浸种5 d、50%和30%的基质含水量、播种深度1 cm、混合土基质、50 mg·L^-1赤霉素浸种12 h以及全破处理的发芽率在各对比的处理中均最高。浸种时间和基质含水量对幼苗叶长和枝高均有显著影响(P<0.05),其他处理对幼苗生长无显著影响。综上可知,赤苍藤种子育苗时,可先浸种5 d或用50 mg·L^-1赤霉素浸种12 h...     

不同含水量对荆芥种子活力的影响

以荆芥Schizonepeta tenuifolia(Benth.)Briq.种子为材料,探究不同含水量荆芥种子活力差异;经过人工老化处理,比较不同含水量荆芥种子之间抗老化劣变能力差异。结果表明荆芥种子由初始含水量10.04%降至7.11%～5.88%时,活力水平较高;经过人工老化处理后,含水量在7.11%～5.88%的荆芥种子,活力指和发芽率数较高,表现较强的抗老化劣变能力;含水量为5.88%的荆芥种子活力指数最高,发芽率最高,POD酶活性较高,种子浸出液以及MDA积累量较少。降低荆芥种子含水量至7.11%～5.88%,能使种子维持在较高活力水平,利于荆芥种子的利用和长时间贮存。     

陇蜀杜鹃种子发芽率的研究

对陇蜀杜鹃种子做了不同处理的发芽试验,结果表明;陇蜀杜鹃种子发芽的适宜温度为１０℃￣１５℃,用纯乙醚,９５％乙醇溶液及一定浓度的硫酸,盐酸,硝酸,氢氧化钠等处理种子后,均能显著地提高种子发芽率;不覆土播种较覆土３ｍｍ的发芽率高;种子贮藏１９个月后的发芽率较贮藏７个月后的发芽率高。     

岩黄连种子繁殖研究

于2003年4月至2004年4月在广西植物研究所实验场内进行岩黄连(Coryd a lis sax icola Bun ting)种子繁殖试验。试验种子分为东兰类型、贵州类型和马山类型。试验前先测定种子的基本情况,然后以东兰类型的种子分别进行不同着生部位、贮藏方法、贮藏时间、播种基质试验。试验结果是东兰类型的种子发芽率最高,为27.75%,贵州类型的最差,仅为16.13%。播种基质以火土加肥泥的最好,种子发芽率为21.25%。种子贮藏以纸袋密封置于低温贮藏最好,发芽率为25.75%。种子以着生在果穗中部的发芽率最高,为28.75%,岩黄连选种时应注重保留中部种子。岩黄连种子没有休眠期,采收后即可播种,最好的播种期是4~8月份。     

几种热带亚热带果树“顽拗型”种子的贮藏研究

顽拗型种子在自然干燥条件下极易丧失发芽力:荔枝经5天、龙眼6天、黄皮7天发芽力基本消失,其含水量分别从49％下降至30％、从37.6％下降至20.9％、从52.5％下降至29.2％。采用聚乙烯袋装保湿贮藏,可以明显延长种子寿命。荔枝种子在5℃下湿藏60天后发芽率仍达89.5％,100天后下降至36％;龙眼种子在5℃或30℃中湿藏,40天后发芽率均在90％以上,100天后,5℃中湿藏的下降至15.6％,而30℃中湿藏的仍保持87.5％;黄皮种子在5℃或30℃中湿藏100天,对发芽率没有影响,但在5℃下贮藏200天,下降至55％,而在30℃下贮藏350天,仍保持100％的发芽率。     

小麦种子超干燥储藏的研究

种子超干燥储存 ,又称超低含水量贮藏 ,是指将种子的水分降至 5 %以下 ,密封后置于常温条件下贮藏。通过降低水份 ,以干燥代替低温 ,在常温条件下 ,使种子具有低温贮藏的效应。早期的超干是指种子水分低于 5 % ,1994年提出的新的超干定义为种子干燥至 2 0℃ ,10 - 12 %的相对湿度下平衡所得的含水量。种子超干贮藏的原始研究 ,可以追溯到本世纪初 ,1918年 ,Harrington发现大麦、小麦的种子水份降至 1%时 ,生活力不受影响。之后 ,美国、加拿大等国相继出现了超干储藏的报道 ,他们多侧重于种子干燥脱水耐性的生理生化机理方面的研究 (1)。国…     

入侵植物粗毛牛膝菊种子形态及其萌发特性的研究

以入侵植物粗毛牛膝菊为材料,在观察其种子形态特征的基础上,研究其在不同埋种深度、不同温度条件下种子的萌发情况。结果表明:粗毛牛膝菊种子小,长仅为1.3～2.0 mm,具伞形冠毛,利于远距离传播扩散;重量轻,千粒重为0.228 6～0.230 3 g;含水量较低,为5.78%,利于储存。当埋种深度为0～2 cm时,发芽率较高、差异不显著(P0.05);当埋种深度为4～8 cm时,随着埋种深度的增加,发芽率逐渐降低,差异显著(P0.05),且种子的始见发芽时间和发芽持续时间也延长;当埋种深度为10 cm时,发芽率仅为13%,极显著的低于其他处理(P0.01)。10～35℃条件下,粗毛牛膝菊种子虽均可萌发,但在各温度下的发芽率、发芽势、发芽指数之间均存在差异,25℃是其种子萌发的最适温度,发芽率达97.33%,与15℃(90.67%)、20℃(93.33%)及30℃(96.67%)时发芽率差异不显著,而与10℃(12%)和35℃(52.7%)时差异极显著(P0.01),发芽势(90%)、发芽指数(32)与10℃(0; 0.65)、15℃(57.33%; 19.8)、35℃(34%; 10.82)时差异也显著(P0.05),说明低温与高温都会影响粗毛牛膝菊种子的萌发,同时也推迟其萌发时间且出苗不整齐。     

脱水前后七叶树种子发芽率及胚根细胞超微结构的变化

对不同脱水程度的七叶树种子发芽率及种子胚根细胞超微结构进行了测定。结果表明:七叶树种子成熟脱落时含水量(DW)高达1.46 g/g,当含水量(DW)降低到1.07 g/g时,继续脱水就会对发芽率造成严重影响。同时成熟的七叶树种子胚根细胞分化完全,未经脱水的种胚细胞结构完整、清晰,细胞核大、居中,核膜、线粒体内嵴外膜、内质网、高尔基体亦比较清晰,液泡较小;脱水5 d后的种胚细胞中出现呈同心圆膜状结构的内质网;脱水7 d后同心圆膜状内质网增多、面积增大且出现多泡体,回水不能使其恢复,与种子发芽率急剧下降相对应。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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