不同因子对青稞类黄酮提取率的影响

采用乙醇的水溶液为溶剂,青稞粉为原料来浸提青稞类黄酮,研究了乙醇体积分数、提取温度、提取时间、料液比对青稞类黄酮提取率的影响,得出最佳提取条件为:乙醇体积分数为75%,料液比为1:15,浸提温度为40℃,浸提时间1h。     

水稻SUPERMAN类似基因ZOS11-11的表达分析及功能初探

SUPL(SUPERMAN-like)是一类单C2H2型锌指蛋白,SUPL基因在植物生长发育过程中起着重要的调控作用.利用生物信息学分析方法,我们从水稻中找到了一个SUPL基因ZOS11-11,它位于水稻第11号染色体上,编码245个氨基酸.序列分析结果表明,ZOS11-11具有与其它SUPL蛋白相同的功能结构域,包括...     

Molecular cloning and characterization of a porcine Fc gamma RIIb sub-isoform(FcγRIIb1)

Receptors for the Fc fragment of IgG (FcγRs) constitute one of the main effector mechanisms through which IgG immune complexes exert their action. Four FcγRs, FcγRI (CD64) with high affinity, FcγRI with intermediate affinity, FcγRII (CD32) and FcγRIII (CD16) with low affinity, have been identified. There are three FcγRII isoforms (activating FcγRIIa and FcγRIIc, and inhibiting FcγRIIb) existing in humans, one isoform in mice (inhibiting FcγRIIb), and two isoforms in cattle (inhibiting FcγRIIb, activating FcγRIIc). Two splice sub-isoforms of FcγRIIb, FcγRIIb1(b1) and FcγRIIb2(b2), have been identified in humans, mice and cattle, however, few of FcγRIIb sub-isoforms have been investigated in pig. In this study, we describe the molecular cloning, sequencing and characterization of a porcine FcγRIIb sub-isoform, FcγRIIb1. The cDNA encoding porcine FcγRIIb1 was isolated from peripheral blood leucocytes RNA with RT-PCR. The porcine FcγRIIb1 cDNA contains a 951bp open-reading frame, encoding a 316 amino acid transmembrane glycoprotein composed of two immunoglobulin (Ig)-like extracellular domains, a transmembrane region and a cytoplasmic tail with an immunoreceptor tyrosine-based inhibiting motif (ITIM). The porcine FcγRIIb1 shares 98.3% homology and has a 19 amino acid in-frame insertion in cytoplasmic tail when compared with amino acid sequence of DQ026064. Immunofluorescence analysis showed that the glycoprotein encoded by the porcine FcγRIIb1 cDNA was expressed in the stable transfected COS-7 cells, and an immunoglobulin-binding assay showed that it had binding activity for IgG immune complexes. Identification of the porcine FcγRIIb1 will help our understanding of the molecular basis of IgG-FcγR interaction in the porcine immune response.     

Differential effects of soil disturbance and plant residue retention on function of arbuscular mycorrhizal (AM) symbiosis are not reflected in colonization of roots or hyphal development in soil

The effects of soil disturbance and residue retention on the functionality of the symbiosis between medic (Medicago truncatula L.) and arbuscular mycorrhizal fungi (AMF) were assessed in a two-stage experiment simulating a crop rotation of wheat (Triticum aestivum L.) followed by medic. Plants were inoculated or not with the AMF, Glomus intraradices and Gigaspora margarita, separately or together. The contribution of the arbuscular mycorrhizal (AM) pathway for P uptake was determined using ³²P-labeled soil in a small hyphal compartment accessible only to hyphae of AMF. In general AM colonization was not affected by soil disturbance or residue application and disturbance did not affect hyphal length densities (HLDs) in soil. At 4 weeks disturbance had a negative effect on growth and phosphorus (P) uptake of plants inoculated with G. margarita, but not G. intraradices. By 7 weeks disturbance reduced growth of plants inoculated with G. margarita or AMF mix and total P uptake in all inoculated plants. With the exception of plants inoculated with G. margarita in disturbed soil at 4 weeks, the AM pathway made a significant contribution to P uptake in all AM plants at both harvests. Inoculation with both AMF together eliminated the negative effects of disturbance on AM P uptake and growth, showing that a fungus insensitive to disturbance can compensate for loss of contribution of a sensitive one. Application of residue increased growth and total P uptake of plants but decreased ³²P in plants inoculated with the AMF mix in disturbed soil, compared with plants receiving no residue. The AMF responded differently to disturbance and G. intraradices, which was insensitive to disturbance, compensated for lack of contribution by the sensitive G. margarita when they were inoculated together. Colonization of roots and HLDs in soil were not good predictors of the outcomes of AM symbioses on plant growth, P uptake or P delivery via the AM pathway.     

金昌市杂交玉米制种产业现状及发展对策

金昌市于1995年引进杂交玉米制种技术,当年种植效益明显高于同类地区其他作物.随着农民群众认识水平的提高和生产技术及种业市场的不断成熟,2006年玉米制种面积达1万hm2,占甘肃省玉米制种面积的7.5%,产量达5.5万t,占全省杂交玉米种子产量的10.5%,实现产值1-3亿元,玉米制种已成为促进本市农业结构调整和部分乡镇农民增收的支柱性产业.     

基于单片机技术的温室自动控制系统的设计

随着我国农业科技的发展,温室自动控制技术越来越引起人们的关注,成为未来优质高效设施农业的发展趋势。为此,通过市场调研,采用单片机控制技术,进行了温室自动化控制系统的设计开发。通过性能测试实验,取得较好的效果,为将单片机技术引入到温室自动控制系统的后续研究提供了借鉴。     

某微型汽车的麦弗逊前悬架K&C特性仿真分析

利用多体动力学分析软件adams/car,建立了麦弗逊前悬架虚拟样机仿真模型.采用轮跳和静载侧向力加载的方法,对汽车在弯道行驶过程中的K&C特性及其对整车稳态转向特性的影响展开分析研究.仿真结果表明,模型具有较好的不足转向特性,为预测整车稳态转向特性提了仿真与理论依据.     

基于仙农熵的土壤多样性和土地利用多样性关联评价

以南京市为例,将多样性理论与方法应用于土壤和土地利用相关性评价中,对该市1986年和2003年的遥感数据进行了土地利用分类,计算了各土壤类型和各土地利用类型的构成组分多样性指数以及多网格尺度下的空间分布多样性指数,并提出一种用于评价土壤和土地利用相互关系的关联系数,求算了5 km网格尺度下南京市典型土种单元同9种土地利用类型之间的关联系数。研究结果表明,1986年至2003年这十余年间,南京市土地利用的构成组分变化明显,其中1986年的构成组分多样性为0.361,2003年为0.444。2003年南京市土地利用的空间分布离散性更高,5种主要土地利用类型的空间分布多样性均有明显增加。南京市典型土种与各土地利用类型关联系数的计算结果表明,多组关联系数的变化趋势相同,由此推断相比于1986年,2003年南京市土壤与土地利用之间的相互联系更为复杂多变。     

磷酸缓冲液提高菜豆幼苗耐冻力的生理效应

用不同浓度和pH的磷酸缓冲液喷施菜豆叶片,然后低温处理离体叶片,测定叶片的相对含水量、水势、渗透势和低温下的膜透性,以探讨磷酸缓冲液喷施菜豆叶片的适宜浓度,pH及其提高耐冻的生理效应。主要试验结果如下:1.0.1M、pH6.45的磷酸缓冲液可增加菜豆叶片的耐冻力。但这种增强效应是暂时性的。2.处理菜豆叶片24小时后,模拟霜冻处理幼苗的成活率比对照高29.0％。离体叶片在处理后24小时耐冻力最强,低温伤害的临界温度下降0.8℃左右。但随着处理后时间的延长,耐冻力减弱,到120小时,叶片质膜透性己恢复到对照水平。3.菜豆处理后,其叶片相对含水量下降,水势降低,渗透势升高;菜豆叶片脱水2—4％,可以增加叶片的耐冻力。     

Increasing yield potential of hybrid rice through molecular breedingIncreasing yield potential of hybrid rice through molecular breeding

Rice is the staple food for more than half of the world population. The utilization of the wild abortive cytoplasmic male sterility （CMS） in 1970s has significantly raised rice yield potential. But the world＇s annual rice production will have to increase 70 percent over the next 30 years, to keep up with the demends of the growing population.