Three new multidimensional organic-inorganic hybrids based on polyoxometalates and copper coordination polymers with 4,4′-bipyridine ligands

Three new organic-inorganic hybrid materials with 4,4′-bipy ligands and copper cations as linkers, [Cu^II(H₂O)(4,4′-bipy)₂][Cu^II(H₂O)(4,4′-bpy)₂]₂H[Cu^IIP₈Mo₁₂O₆₂H₁₂] · 5H₂O (1), [Cu^I(4,4′-bipy)][Cu^II(4,4′-bipy)]₂ (BW₁₂O₄₀) · (4,4′-bipy) · 2H₂O (2) and [Cu^I (4,4′-bipy)]₃ (PMo₁₂O₄₀) · (pip) · 2H₂O (3) (pip = piperazine; 4,4′-bipy = 4,4′-bipyridine), have been hydrothermally synthesized. The single X-ray structural analysis reveals that the structure of 1 is constructed from [Cu(H₂O)(4,4′-bipy)₂] complexes into a novel, three-dimensional supermolecular network with 1-D channels in which Cu[P₄Mo₆]₂ dimer clusters reside. To the best of our knowledge, compound 1 is the first complex in which the [P₄Mo₆] clusters have been used as a non-coordinating anionic template for the construction of a novel, three-dimensional supermolecular network. Compound 2 is constructed from the six-supported [BW₁₂O₄₀]⁵⁻ polyoxoanions and [Cu^I(4,4′-bipy)] and [Cu^II(4,4′-bipy)] groups into a novel, 3-D network. Compound 3 exhibits unusual 3-D supramolecular frameworks, which are constructed from tetrasupporting [PMo₁₂O₄₀]³⁻ clusters and [Cu^I (4,4′-bipy)_n] coordination polymer chains. The electrochemical properties of 2 and 3 have been investigated in detail.     

国外豆科牧草生物技术研究进展——生物技术在豆科牧草遗传育种研究中的应用

豆科牧草具有重要的经济价值。本文主要从豆科牧草遗传资源鉴定、保存和利用及豆科牧草育种方法和育种策略两个大的方面阐述了生物技术在国外豆科牧草研究中的应用,并重点介绍了体细胞杂交、胚拯救和分子标记技术。     

留桩高度对培两优210再生稻产量和源库性状的影响

水稻主季稻留桩高度是影响再生稻高产的重要因素之一.以两系杂交稻组合培两优210为研究材料,在主季稻收割时设3个留桩高度处理(40 cm、20 cm和10 cm),研究主季稻留桩高度对再生稻产量及源库性状的影响.结果表明,随留桩高度的降低,(1) 培两优210再生稻生育期延长,株高、穗长与叶面积指数增加;(2) 灌浆期间叶片磷酸蔗糖合成酶活性衰减率减小,作物生长率增加,节间维管束数目和大小及枝梗过氧化氢酶活性增加;(3) 茎鞘非结构碳水化合物积累和输出速率增加,比叶重和粒叶比提高,穗总粒数增加,进而增加产量.两系杂交稻培两优210作中稻栽培时其适宜留低桩,留桩高度10 cm处理再生稻具有"源"足"流"畅"库"大的特点.     

栽培稻种子含氮量的基因型差异

采用田间试验研究了421个常规籼稻、63个常规粳稻和82个籼型杂交稻品种种子含氮量的基因型差异。结果表明,栽培稻种子含氮量变幅在0.85%~2.55%,平均为1.39%。种子平均含氮量最高的是籼型杂交稻,高达1.46%,显著高于常规粳稻(1.39%)和常规籼稻(1.37%)。不同类型的栽培稻种子含氮量呈正态分布,但频数分布最高的区间存在一定的差异。以50%品种的种子含氮量(累积百分数从25%~75%)为依据,常规籼稻、常规粳稻、籼型杂交稻分别集中在1.21%~1.52%、1.21%~1.51%、1.36%~1.53%。LSR测验表明,籼型杂交稻极差显著小于常规籼稻和常规粳稻,但常规粳稻与常规籼稻的差异未达显著水平,即籼型杂交稻种子含氮量比常规籼稻和常规粳稻的分布更加集中。不同类型栽培稻内的种子含氮量极差较大,可分为若干组,且各组间达极显著差异。     

利用酵母双杂交系统研究植物与病毒蛋白相互作用的进展

在长期进化中,植物形成了抵御病毒等病原微生物侵染的精细防御系统。在病毒侵染、复制和传播过程中,其编码的一些蛋白,如外壳蛋白、运动蛋白、复制酶类等能够与植物基因编码的蛋白发生相互作用。酵母双杂交系统是体外研究蛋白质间相互作用的有利工具,不但可以用于研究已知蛋白质的互作,还可以发现新蛋白,揭示特定蛋白互作网络与作用机制,在植物蛋白与病毒蛋白互作研究中已得到广泛的利用。本文主要综述利用酵母双杂交系统研究植物与病毒蛋白相互作用的国内外进展。     

A genetic test for recruitment enhancement in Chesapeake Bay oysters, Crassostrea virginica, after population supplementation with a disease tolerant strain

Many of the methods currently employed to restore Chesapeake Bay populations of the eastern oyster, Crassostrea virginica, assume closed recruitment in certain sub-estuaries despite planktonic larval durations of 2–3 weeks. In addition, to combat parasitic disease, artificially selected disease tolerant oyster strains are being used for population supplementation. It has been impossible to fully evaluate these unconventional tactics because offspring from wild and selected broodstock are phenotypically indistinguishable. This study provides the first direct measurement of oyster recruitment enhancement by using genetic assignment tests to discriminate locally produced progeny of a selected oyster strain from progeny of wild parents. Artificially selected oysters (DEBY strain) were planted on a single reef in each of two Chesapeake Bay tributaries in 2002, but only in the Great Wicomico River (GWR) were they large enough to potentially reproduce the same year. Assignment tests based on eight microsatellite loci and mitochondrial DNA markers were applied to 1579 juvenile oysters collected throughout the GWR during the summer of 2002. Only one juvenile oyster was positively identified as an offspring of the 0.75 million DEBY oysters that were planted in the GWR, but 153 individuals (9.7%) had DEBY ×wild F1 multilocus genotypes. Because oyster recruitment was high across the region in 2002, the proportionately low enhancement measured in the GWR would not otherwise have been recognized. Possible causes for low enhancement success are discussed, each bearing on untested assumptions underlying the restoration methods, and all arguing for more intensive evaluation of each component of the restoration strategy.     

Identification of correct regions in protein models using structural, alignment, and consensus information

In this study we present two methods to predict the local quality of a protein model: ProQres and ProQprof. ProQres is based on structural features that can be calculated from a model, while ProQprof uses alignment information and can only be used if the model is created from an alignment. In addition, we also propose a simple approach based on local consensus, Pcons-local. We show that all these methods perform better than state-of-the-art methodologies and that, when applicable, the consensus approach is by far the best approach to predict local structure quality. It was also found that ProQprof performed better than other methods for models based on distant relationships, while ProQres performed best for models based on closer relationship, i.e., a model has to be reasonably good to make a structural evaluation useful. Finally, we show that a combination of ProQprof and ProQres (ProQlocal) performed better than any other nonconsensus method for both high- and low-quality models. Additional information and Web servers are available at: http://www.sbc.su.se/~bjorn/ProQ/.     

NaCl胁迫对杂交狗牙根品种‘苏植2号’和‘Tifgreen’生长及Na＋和K＋积累的影响

对0（对照）和20g·L-1NaCl胁迫条件下杂交狗牙根（Cynodondactylon×C.transvaalensis）品种‘苏植2号’（‘SuzhiNo.2’）和‘Tifgreen’不同部位的生长状况以及Na＋和K＋积累的差异进行了研究,并分析了2个品种间Na＋、K＋转运调控机制的差异。结果显示：在NaCl胁迫条件下,2个品种的叶片相对枯黄率、地下茎和根系的相对干质量、叶片和根系的Na＋含量和Na＋/K＋比以及钠钾选择性转运系数增加;修剪茎叶及冠层和地上部的相对干质量、植株相对总干质量以及叶片和根系的K＋含量均降低,但茎叶含水量无显著变化。NaCl胁迫条件下,不同土层中2个品种的根系相对干质量均不同程度增加,且20-40和40-60cm土层中根系干质量的增幅大于0-20cm土层;在0-20cm土层中2个品种根系的分配比例均有所降低,而在20-40和40-60cm土层中则不同程度提高。与‘Tifgreen’相比,NaCl胁迫条件下‘苏植2号’叶片相对枯黄率、Na＋含量和Na＋/K＋比更低,修剪茎叶及冠层和地上部的相对干质量、植株相对总干质量、叶片K＋含量和钠钾选择性转运系数更高;在20-40和40-60cm土层中‘苏植2号’根系相对干质量显著高于‘Tifgreen’,根系分配比例总体也高于‘Tifgreen’。综合比较结果表明：‘苏植2号’的抗盐性强于‘Tifgreen’,可能与其深层根系分配量更高和钠钾选择性转运能力较强有关。     

不同超级杂交稻组合期剑叶14C-同化物的转运及分配与早衰关系的研究

选取具有不同早衰特性的超级杂交稻组合两优培九、Y两优1号和培两优E32为供试材料,借助14C同位素示踪技术对其不同生育期剑叶14C同化物分配及转化进行了研究。结果表明:随着生育期的推进,剑叶(源)同化物向穗中(库)的转运比例逐渐增加,在供试组合中以两优培九分配效率最高,Y两优1号次之,培两优E32最低;剑叶14C-同化物在供试组合中的转运能力也有类似的趋势,在3个超级杂交稻组合中,以两优培九"源、库、流"的协调性最好,Y两优1号次之,培两优E32最差。