西瓜PME基因生物信息学分析及克隆

研究从拟南芥(Arabidopsis thaliana)4个果胶甲酯酶基因和2个来自东北农业大学西甜瓜分子育种课题组西瓜转录组数据分析的果胶甲酯酶基因入手,通过BLAST比对方法在葫芦科数据库中鉴定甜瓜(Cucumis melo L.)、西瓜(Citrullus lanatus)果胶甲酯酶同源基因,预测分析其生物信息学...     

山橙内生真菌的抑菌活性初步研究

[目的]从山橙(Melodinus suaveolens Champ.ex Benth)中分离对植物病原真菌具有拮抗活性的内生真菌,为研发新型高效生物农药提供理论依据.[方法]采用组织培养法对山橙进行内生真菌的分离与纯化,结合菌种形态学和18S rDNA序列比对对其内生真菌进行鉴定;采用平板对峙法和菌丝生长速率法测定内生真菌对香蕉枯萎病4号小种、香蕉炭疽病菌和火龙果溃疡病菌等13株供试植物病原真菌的抑菌活性.[结果]从山橙的根、枝和叶中分别分离得到4、5和11株共20株内生真菌,平板对峙测定结果显示其中的菌株M4对白腐盾壳霉菌、向日葵霜霉病菌、禾谷镰刀菌、茄子黄萎病菌、水稻稻瘟病菌和火龙果溃疡病菌等6株植物病原真菌的抑制率均在30.00%以上,表现出较好的抗菌活性.结合形态特征与18S rDNA序列分析鉴定,确定菌株M4为Phanerochaete sp.,其菌株发酵液在20 mg/mL浓度下对马铃薯黄萎病大丽轮枝菌、马铃薯黑白轮枝菌、禾谷镰刀菌、茄子黄萎病菌、西瓜枯萎病菌、马铃薯立枯丝核菌和香蕉枯萎病4号小种等7株病菌均具有一定的抑制作用,其中对禾谷镰刀菌的抑制效果最佳,抑制率为40.92%,显著高于对其他病原菌的抑制率(P<0.05).[结论]山橙内生真菌富含抑菌活性菌株,蕴藏着潜在的抑菌活性物质,具有良好的应用前景.     

小豆矮秆窄叶突变基因对农艺性状的影响

【目的】研究小豆矮秆窄叶突变体(nld)的遗传行为及观察矮秆窄叶突变基因控制的农艺性状的变化。【方法】选用高秆小豆种质资源GM904与nld进行杂交,对亲本和F2、F3、F4各世代分离群体中个体形态进行调查统计,对株高、茎粗、主茎节数、第1至5节间长、前10节间长、单株粒数、百粒重、单株产量、荚长、荚宽、单株荚数等15个农艺性状进行调查分析。【结果】遗传分析结果表明,突变体中矮秆窄叶性状由一对隐性单基因控制。各性状间存在一定的显著或极显著差异,其中株高、茎粗、主茎节数、前10节间长、荚长、单株荚数的广义遗传力达到0.9以上,可作为小豆杂交育种的选择指标。【结论】矮秆窄叶突变基因导致株高变矮,叶变窄,茎变细,主茎节数减少,各节间长缩短,荚变小,产量显著降低。     

建鲤组织蛋白酶L 的原核表达、纯化鉴定及多克隆抗体的制备

对原核表达的重组建鲤组织蛋白酶L(Cathepsin L,CAT L)蛋白进行尿素洗涤和Ni-NTA亲和层析纯化,该目的蛋白经300 mmol/L咪唑洗脱为单一峰,SDS-PAGE结合TSK-GEL G2000SWxl凝胶过滤高效液相色谱分析表明重组CAT L获得了高度纯化,分子量约28 k D,纯度超过95%。Z-Phe-Arg-MCA底物测活法显示该重组CAT L表现为半胱氨酸蛋白酶活性,能与其内源抑制因子Cystatin以1︰1的摩尔比结合,具有生物学活性。以纯化的重组CAT L蛋白免疫Balb/C小鼠获得抗血清,经ELISA法检测获得的CAT L抗血清效价高于1︰512000;Western blotting鉴定结果表明该抗体具有良好的特异性,能够识别原核表达的重组CAT L蛋白。免疫组织化学分析结果表明,该抗体还能识别建鲤小肠、肝胰脏、脾、背肌和心肌组织表达的内源性CAT L蛋白。因此可利用该抗体从蛋白水平检测CAT L在鱼类不同组织中的表达和分布情况。     

Development of Researching the Synthetical Application of Compound Microorganisms

This article summarized that compound microorganisms had many advantages compared with single strain such as symbiosis, co prosperity co culture, so it can cut down the cost, unchain the feedback repression in fermentation and improve the efficiency of production. It described the resources, constitutes and physiological characteristics of compound microorganisms with examples, which displayed its superiority farther. It is showed that the application of compound microorganisms to the agriculture,industry,medicine and environment variable analyzed etc. The problems lying in the application of the compound microorganisms technology and some views on solving these problems. Compound microorganisms are expected to serve all the fields more and achieve more economic and social efficiency.     

Prevalence and risk factors of Coxiella burnetii seropositivity in Danish beef and dairy cattle at slaughter adjusted for test uncertainty

Antibodies to Coxiella burnetii have been found in the Danish dairy cattle population with high levels of herd and within herd seroprevalences. However, the prevalence of antibodies to C. burnetii in Danish beef cattle remains unknown. The objectives of this study were to (1) estimate the prevalence and (2) identify risk factors associated with C. burnetii seropositivity in Danish beef and dairy cattle based on sampling at slaughter.     

Labile, recalcitrant, and microbial carbon and nitrogen pools of a tallgrass prairie soil in the US Great Plains subjected to experimental warming and clipping

Carbon (C) and nitrogen (N) fluxes are largely controlled by the small but highly bio-reactive, labile pools of these elements in terrestrial soils, while long-term C and N storage is determined by the long-lived recalcitrant fractions. Changes in the size of these pools and redistribution among them in response to global warming may considerably affect the long-term terrestrial C and N storage. However, such changes have not been carefully examined in field warming experiments. This study used sulfuric acid hydrolysis to quantify changes in labile and recalcitrant C and N fractions of soil in a tallgrass prairie ecosystem that had been continuously warmed with or without clipping for about 2.5 years. Warming significantly increased labile C and N fractions in the unclipped plots, resulting in increments of 373 mg C kg⁻¹ dry soil and 15 mg N kg⁻¹ dry soil, over this period whilst clipping significantly decreased such concentrations in the warmed plots. Warming also significantly increased soil microbial biomass C and N in the unclipped plots, and increased ratios of soil microbial/labile C and N, indicating an increase in microbial C- and N-use efficiency. Recalcitrant and total C and N contents were not significantly affected by warming. For all measured pools, only labile and microbial biomass C fractions showed significant interactions between warming and clipping, indicating the dependence of the warming effects on clipping. Our results suggest that increased soil labile and microbial C and N fractions likely resulted indirectly from warming increases in plant biomass input, which may be larger than warming-enhanced decomposition of labile organic compounds.     

生物质微米燃料富氧燃烧特性分析

采用热重分析法对生物质微米燃料在不同体积分数氧条件下的燃烧特性进行研究,结果表明:随着氧体积分数的增加,生物质微米燃料的挥发分初析出温度、着火温度和燃尽温度不断降低,可燃性增强;平均和最大质量损失速率呈增加趋势,提高了燃烧强度.燃烧特性指数随着氧体积分数的增加而变大,当氧体积分数达到60%后,改善趋势变缓.     

生物复合菌肥“地霸”的菌群分离鉴定及生物学特性的初步研究

对生物复合菌肥进行菌群的分离鉴定、含菌量的测定和比较以及菌株生物学特性的初步研究.该生物复合菌肥中含有活性较高的固氮菌(维氏固氮菌)、钾细菌和无机磷细菌,每克菌肥中细菌总数达到2.0亿～2.5亿.固氮菌在修改的Dobereiner无氮培养基上生长良好,固氮活性较强,该菌生长最适温度在20～32℃之间,生长的pH值范围是5.5～8.5,最适pH值是7.5.