植物根际促生菌(PGPR)的研究与应用前景

植物土传病害难以防治 ,植物根际促生菌 (plantgrowth promotingrhizobacteria ,PGPR)的深入研究和发展为解决这一难题展现了诱人的前景 .PGPR能够高密度地在植物根际定殖 ,兼有抑制植物病原菌、根际有害微生物 ,以及促进植物生长并增加作物产量的作用 ,更重要的是有些PGPR能够诱导植物产生系统抗性 (inducedsystemicresistance ,ISR) ,从而提高植物整体的抗病能力 .近 2 0年来 ,国外这一领域的研究十分活跃 ,已有很多成功应用的PGPR产品 ,国内应大力加强基础与应用的研究 ,并推进其产业化的发展 .

中国东北地区的盐渍土资源

通过长期区域土壤考察,我国东北地区盐渍土资源的面积约为7 66×106hm2,其中松嫩平原的盐渍土面积占39 3%,西辽河沙丘平原占30 3%,辽河冲积平原占12 8%,呼伦贝尔盟高平原占9 3%,滨海平原占7 9%,三江平原仅占0 4%而已,20世纪80年代不同辖区所获的土壤普查结果与之相接近。在上述的盐渍土资源面积中,其潜在盐渍土的面积约占34%。在开发利用方面,盐渍土的耕地面积已由20世纪50年代的占其总耕地面积的21 4%,增加为80年代的37 8%,呈显著增长之势。水田灌区土壤普遍脱盐,作物高产稳产,已属新型的人工生态系统。在盐渍土旱作区,农作物亦已普遍持续增产,惟局部土壤的脱盐状况尚不甚稳定,其西部地区的盐渍化面积呈明显蔓延之势,主要原因在于大面积天然草场的土壤盐渍度加剧,生产力普遍下降。上述中国东北地区盐渍土资源的面积约占全国盐渍土面积的7.9%,战略地位重要,其实现农业可持续发展的开发利用任务仍然十分艰巨。

中国东北植被生态学研究中的焦点问题

中国东北植被经过半个多世纪的系统研究 ,但有关植被生态学一些争论性问题尚未统一 .本文仅就作者近年来研究工作涉及到的内容和关注的问题 ,提出一些看法 :1)中国东北植被地带性分布规律可用Kira的温暖指数 (WI)、寒冷指数 (CI)和作者的湿度指数 (HI)进行定量解释 .2 )大兴安岭北部山地 ,在海拔14 0 0m以上存在冻原植被 ,是作者于 196 3年首次发现的我国第三块冻原植被 ,其WI <15℃·月 .3)大小兴安岭植被分界线是我国植被区划中第一级分区界线 ,其位置在爱辉 -果松沟 -嫩江以南附近 ,WI为 4 5℃·月 .4 )大兴安岭植被地带性分异显著 ,南段、中段为典型草原地带和森林草原地带 ,北段为针叶林地带 ,HI值分别为 3 5～ 5 5、5 5～ 7 5、>7 5mm/℃·月 .大兴安岭东麓阔叶林是森林草原带上的森林植被类型 .5 )东北东部山地岳桦林是山地植被垂直带谱重要组成部分之一 ,是山地森林垂直分布林线 ,WI为 2 0～ 15℃·月为地带性植被类型 ,而WI>2 0℃·月为非地带性植被类型 .6 )内蒙古浑善达克沙地云杉林是陆地上非常罕见的森林生态系统类型 ,但这种云杉林究竟是哪一树种组成 ,在中国植物分类上一直是个争论性问题 ,作者通过核型分析和同工酶实验进一步证明是一个新种即沙地云杉Piceamongolica(H .Q .Wu)W .D .

中国苔类新记录种:附基缺萼苔(Gymnomitrionlaceratum(Steph.)Horik.

报道产于西藏的中国苔类植物缺萼苔科缺萼苔 1个新记录种 :附基缺萼苔 (Gymnomitrionlaceratum(Steph .)Horik .)。该种主要特征为植物体具残存但可辨别的腹叶 ,有别于该科其它种类。

近十年东部发达区农业地位与功能演变分析

文章应用近10年统计资料,并以东部发达地区为例,对中国农业生产的特点进行了分析。结果表明:第二、三产业的迅速发展使农业在GDP中的比重快速下降,但由于非农产业发展快而农业劳动力转移速度慢,农业比较劳动生产率比全国还要低且继续保持下降趋势;东部发达地区在整体上已经进入了农户以非农收入为主阶段,农业在总体上呈现停滞不前现象,工资性收入正在成为农村居民收入的主要来源;粮食作物播种面积和总产量迅速下降,东部发达区已经成为粮食短缺地区,并且粮食缺口还在加大。文章进而对这种变化规律的可能影响及相应对策进行了论述。

鱇白鱼的池塘人工驯养方法

本发明涉及一种鱇白鱼的池塘人工驯养方法，属鱼产品养殖技术领域。鱇白鱼的池塘人工驯养方法为先用消毒剂对池塘进行清塘，随后放入清水，其水深为0.8米，此时将鱼苗放入池中，驯养期间水温在8-25℃，鱼苗投喂时间为每日二次，投喂的饲料分别为：一个月前喂蛋黄或轮虫，随后喂蛋黄、豆浆和混合饲料，5个月后投喂混合饲料，饲料的喂量为蛋黄每次5个，豆浆每天0.5公斤黄豆研磨成浆，混合饲料早期每次1公斤，随着鱼体长大酌情增量。采用本鱇白鱼的池塘人工驯养方法，具有操作简便，成本低廉，鱼苗成活率高，并将在自然状况下，生长到5厘米左右时便进入40-50米的深水区生长发育，直到性成熟后才洄游到浅水区的砾石砂滩和溶洞出水口处产卵的抚仙湖特有鱼类——鱇白鱼驯化成为一种池塘人工养殖品种等优点。

鱇白鱼饵料的人工培育方法

本发明涉及一种鱇白鱼饵料的人工培育方法，属鱼产品养殖技术领域。鱇白鱼饵料的人工培育方法经繁殖藻类、接种轮虫、生长枝角类和桡足类过程完成；其中：繁殖藻类过程为在饵料池的水中放入蒿草，蒿草在20-24℃下浸泡5天后藻类生长繁殖达高峰；接种轮虫过程为在第6天挖取长年养殖鲤鱼池的底泥，加入生石灰搅拌成浆后放入饵料培育池，接种轮虫后辅以豆浆肥水和菌体促进轮虫的生长繁殖，在20-24℃的温度下经6天轮虫生长繁殖达高峰；生长枝角类和桡足类过程为在20-24℃的温度下再经7天枝角类和桡足类生长繁殖达高峰。本发明具有简单易行、成本低、使鱇白鱼的驯养顺利实现了食性的转化，避免了死亡。同时为野生虑食性经济鱼类的人工养殖解决饵料来源。

Large scale, templateless, surfactantless route to rapid synthesis of uniform poly(o-phenylenediamine) nanobelts

We reported the interesting finding that large scale uniform poly(o-phenylenediamine) nanobelts with several hundred micrometers in length, several hundred nanometers in width, and several ten nanometers in height can be rapidly yielded from an o-phenylenediamine-HAuCl4 aqueous solution without the additional introduction of other templates or surfactants at room temperature.

四种电化学分析仪器的研制

本报告介绍我们实验室以原有研究工作为基础，结合国家十五科技攻关课题，适应市场需要，研发的生化需氧量(BOD)快速监测仪、溶氧(DO)在线检测仪、毛细管电泳电化学发光检测仪(CE/ECL)、USB插头式超微型电化学研究系统(uECS)等四种电化学分析仪器。BOD、DO仪采用纳米、自组装等技术制作电化学探头，可实现对水体中的BOD、DO的快速、灵敏的检测，所得结果与使用传统的方法相一致，而所需时间很短，可以实时、在线监测;CE/ECL仪系结合了毛细管电泳的高分离能力和电化学发光的高灵敏度的特点开发出的整体仪器;uECS突破了原有电化学分析仪器的概念，结合了先进的USB2.0技术，整个系统体积小巧(如U盘)，通过计算机的USB接口提供电源并进行高速数据传输，具有一般研究型电化学仪的各项功能，并且具有较强的可扩展性。

Robust core-shell supramolecular assemblies based on cationic vesicles and ring-shaped {Mo-154} polyoxomolybdate nanoclusters: Template-directed synthesis and characterizations

Substantial progress has been made recently in extending the supramolecular assembly of biomimetic structures to vesicle-based sophisticated nanocomposites and mesostructures. We report herein the successful preparation of unilamellar surfactant vesicles coated with a monolayer of ring-shaped {Mo-154} polyoxometalate (POM) nanoclusters, (NH4)(28)[Mo-154 (NO)(14)O(448)Hi(4)(H2O)(70)].approximate to 350H(2)O, by coulomb attractions using preformed didodecyldimethylammonium bromide (DDAB) surfactant vesicles as templates. The resultant vesicle-templated supramolecular assemblies are robust (they do not disintegrate upon dehydration) both at room-temperature ambient and vacuum conditions, as characterized by conventional transmission electron microscopy (TEM) and atomic force microscopy (AFM). The flexibility of the complex soft assemblies was also revealed by AFM measurements. The effect of POM-vesicle coulomb attractions on the dimensions of the templating vesicles was also investigated by using dynamic light scattering (DLS).Although origins of the structure stability of the as-prepared supramolecular assemblies are not clear yet, the nanometer scale cavities and the related properties of macroions of the POM clusters may play an important role in it.

固相反应法合成Pt/MoO_3及其电催化作用

采用固相合成的方法制得直接甲醇燃料电池催化甲醇氧化的Pt/MoO3.XRD分析、循环伏安测试表明,Pt/MoO3对甲醇的氧化具有较好的催化作用,氧化峰电位出现在0.63V(vs.SCE),峰电流密度可达78.1mA·cm-2.

Enriched accumulation and biotransformation of selenium in the edible seaweed Laminaria japonica

Accumulations of selenium in kelp Laminaria japonica cultured in seawater was achieved by adding selenite (Na2SeO3) with or without N-P (NaNO3 + NaH2PO4) nutrients at different concentrations. Biotransformation of selenium in the kelp was investigated through measuring the selenium of biological samples and different biochemical fractionations. The results showed that the optimal selenite-enrichment concentration is 200 mg L-1, which can allow the kelp to accumulate a total selenium content from 0.51 +/- 0.15 to 26.23 +/- 3.12 mug g(-1) of fresh weight (fw). Selenium composition analysis of kelp (control group) showed that selenium is present as organic selenium, which is up to 86.22% of the total selenium, whereas inorganic selenium is barely 4.85%. When L. japonica was exposed for 56 h in seawater containing 200 mg L-1 Na2SeO3, the organic selenium was 16.70 mug g(-1) of fw (68.23%) and inorganic selenium was 4.71 mug g(-1) of fw (19.26%). The capability of accumulation of selenium was further enhanced by adding N-P nutrients to the selenite-enriched medium. Total selenium is increased to be 33.65 mug g(-1) of fw at optimal concentration of N-P nutrient (150 mg L-1 NaNO3 and 25 mg L-1 NaH2PO4), whereas the inorganic selenium was not increased and remained at 4.597 mug g(-1) of fw (13.36%), and the increased part of selenium was organic selenium. This implied that kelp L. japonica could effectively transform inorganic selenium into organic selenium through metabolism.

Characterization of the main light-harvesting chlorophyll a/b-protein complex of green alga, Bryopsis corticulans

The main light-harvesting chlorophyll a/b -protein complex (LHC II) has been isolated directly from thylakoid membranes of shiphonous green alga, Bryopsis corticulans Setch. by using two consecutive runs of anion exchange and gel-filtration chromatography. Monomeric and trimeric subcomplexes of LHC 11 were obtained by using sucrose gradient ultracentrifugation. Pigment analysis by reversed-phase high performance liquid chromatography showed that chlorophyll a (Chl a), chlorophyll b (Chl b), neoxanthin, violaxanthin and siphonaxanthin were involved in LHC 11 from B. corticulans. The properties of electronic transition of monomeric LHC II showed similarities to those of trimeric LHC II. Circular dichroism spectroscopy showed that strong intramolecular interaction of excitonic dipoles between Chl a and between Chl b exist in one LHC II apoprotein, while the intermolecular interaction of these dipoles can be intensified in the trimeric structure. The monomer has high efficient energy transfer from Chl b and siphonaxanthin to Chl a similarly to that of the trimer. Our results suggest that in B. corticulans, LHC II monomer has high ordered pigment organization that play effective physiological function as the trimer, and thus it might be also a functional organization existing in thylakoid membrane of B. corticulans.

Product monitoring and quantitation of oligosaccharides composition in agar hydrolysates by precolumn labeling HPLC

Since the discovery of multiple bioactivities for agarobiose oligomers, a quantitative method has been in great need to monitor the agarobiose oligomers. This report demonstrates that agarobiose oligomers can be separated with high resolution in HPLC after introducing a-naphthylamine into compounds. Agarobiose oligomers ranged from biose to decaose were isolated by Sephadex column. HPLC analysis indicated that each oliomer could be quantified with good linearity and a low detection limit of 0.1-4 mug/ml. The chromatographic profiles of agaro-oligosaccharides with different hydrolysis modes (hydrochloride, citric acid, solid acid, and hydroxyl radical degradation) showed that agarobiose could be obtained more than 57.8% using solid acid mediated hydrolysis, while hydrochloride acid could degrade agar into a series of agaro-oligosaccharides from biose to decaose. The yield of oligosaccharides was low if hydrolyzed by citric acid. The Fenton degradation can increase the speed of hydrolysis, but the product was complex. (C) 2004 Elsevier B.V. All rights reserved.