山西马身猪及其杂交后代H-FABP基因的PCR-RFLP检测

运用PCR-RFLP法检测马身猪及其杂交后代H-FABP基因多态性。结果表明,马身猪在Hinf Ⅰ-RFLP位点上有HH和Hh两种基因型,在HaeⅢ-RFLP位点上只有DD基因型,在HinfⅠ*-RFLP位点上有BB和Bb两种基因型,等位基因以h、D、B占优势,其频率分别为0．958、1．000和0．968。其杂交后代在HaeⅢ-RFLP位点上只检测到两种基因型DD和Dd。     

不同光强对入侵种三裂叶豚草表型可塑性的影响

通过人工遮光,研究了不同光照强度下入侵植物三裂叶豚草的形态、生物量分配以及光合特性的表型可塑性.结果表明:与对照相比,遮光条件下,三裂叶豚草的株高、冠宽、单株叶面积、比叶面积和叶生物量比重显著增加,总生物量、单位叶面积生物量和根冠比减小;在全光照条件下,其冠宽和单株叶面积较小,根冠比较大,有利于高温强光下减少水分散失,表现出对不同光强较强的形态和生物量可塑性.遮光使三裂叶豚草叶片的日均净光合速率、蒸腾速率和气孔导度下降,胞间CO2浓度上升.正午光照最强时,低遮光处理植株的净光合速率、蒸腾速率和气孔导度最大.中遮光和高遮光条件下,其叶绿素含量显著增加,叶绿素a/b显著减小,有利于提高三裂叶豚草的光能利用效率,以适应弱光环境.     

The expression,function and regulation of mitochondrial alternative oxidase under biotic stresses

To survive, plants possess elaborate defence mechanisms to protect themselves against virus or pathogen invasion. Recent studies have suggested that plant mitochondria may play an important role in host defence responses to biotic stresses. In contrast with animal mitochondria, plant mitochondria possess a unique respiratory pathway, the cyanide‐insensitive alternative pathway, which is catalysed by the alternative oxidase (AOX). Much work has revealed that the genes encoding AOX, AOX protein and the alternative respiratory pathway are frequently induced during plant–pathogen (or virus) interaction. This raises the possibility that AOX is involved in host defence responses to biotic stresses. Thus, a key to the understanding of the role of mitochondrial respiration under biotic stresses is to learn the function and regulation of AOX. In this article, we focus on the theoretical and experimental progress made in the current understanding of the function and regulation of AOX under biotic stresses. We also address some speculative aspects to aid further research in this area.     

Increased temperature and precipitation interact to affect root production,mortality, and turnover in a temperate steppe: implications for ecosystem C cycling

Fine root production and turnover play important roles in regulating carbon (C) cycling in terrestrial ecosystems. In order to examine effects of climate change on root production and turnover, a field experiment with increased temperature and precipitation had been conducted in a semiarid temperate steppe in northern China since April 2005. Experimental warming decreased annual root production, mortality, and mean standing crop by 10.3%, 12.1%, 7.0%, respectively, while root turnover was not affected in 2006 and 2007 by the warming. Annual root production and turnover was 5.9% and 10.3% greater in the elevated than ambient precipitation plots. Changes in root production and mortality in response to increased temperature and precipitation could be largely attributed to the changes in gross ecosystem productivity (GEP) and belowground/aboveground C allocation. There were significant interactive effects of warming and increased precipitation on root productivity, mortality, and standing crop. Experimental warming had positive and negative effects on the three root variables (root production, mortality, standing crop) under ambient and increased precipitation, respectively. Increased precipitation stimulated and suppressed the three root variables in the unwarmed and warmed subplots, respectively. The positive dependence of soil respiration and ecosystem respiration upon root productivity and mortality highlights the important role of root dynamics in ecosystem C cycling. The nonadditive effects of increased temperature and precipitation on root productivity, mortality, and standing crop observed in this study are critical for model projections of climate–ecosystem feedbacks. These findings indicate that carbon allocation is a focal point for future research and that results from single factor experiments should be treated with caution because of factor interactions.     

有丝分裂细胞死亡

细胞死亡有坏死、凋亡、裂亡、自体吞噬等多种方式。细胞裂亡指细胞经过一次有丝分裂后才开始死亡的现象。本文综述了对于细胞裂亡这种新型细胞死亡方式的初步认识。     

植物叶片衰老与氧化胁迫

叶片衰老是叶片生长发育进程中的最后阶段,与活性氧伤害有着密切的关系。介绍了植物叶片衰老过程中活性氧产生及清除系统的变化,讨论了对水分胁迫与氧化胁迫的交叉抗性,并对下一步的研究作出了展望。     

人干扰素α-2b基因在烟草中的表达研究

应用PCR的技术从质粒pAIFN中扩增人干扰素α-2b(Human interferon α-2b,HuIFN α-2b)编码基因,将其连接到pBI121双元载体构建植物真核表达载体pBIFN;用冻融法将该载体转染根癌农杆菌LBA4404;并用叶盘浸染法转化烟草叶片,经转化的烟草叶片的组织培养,诱导愈伤获得再生植株。通过应用PCR,RT-PCR,Wes-tern blot和WISH/VSV方法检测获得的烟草再生植株,结果表明HuIFN α-2b基因已成功整合进烟草核基因组并表达出具有活性的HuIFN α-2b蛋白。本文对HuIFN α-2b基因在烟草核系统中的表达进行了研究,为进一步在烟草叶绿体系统中该基因的表达研究奠定了基础。     

美常安治疗老年人抗生素相关性腹泻的疗效观察

目的:观察美常安治疗老年人抗生素相关性腹泻的疗效.方法:将79例老年人抗生素相关性腹泻患者随机分为2组,对照组为常规治疗,治疗组在常规治疗的基础上加用美常安治疗.结果:治疗组患者的总有效率明显高于对照组,2组有显著差异(P＜0.05).结论:美常安治疗老年人抗生素相关性腹泻疗效显著.     

不同光强对吴茱萸生长动态和光合日变化的影响

报道了不同生长光强(透光率分别为15%、30%、50%、100%)对吴茱萸的生长和光合日变化的影响。结果表明:生长环境光强对吴茱萸苗期株高、地径和冠面积的影响较大,100%RI下的株高、地径和冠面积明显小于各遮荫处理,其中30%RI下吴茱萸的株高、地径和冠面积最大,这表明苗期强光不利于吴茱萸的生长。随着光强的减弱,吴茱萸增大冠面积与株高有利于截获更多光能。10月下旬,100%RI下吴茱萸净光合速率(Pn)日变化曲线呈"双峰型",11:30～14:30,吴茱萸的Pn、胞间二氧化碳浓度与气孔导度均下降,表明此时的光合午休现象是由气孔部分关闭造成的。各遮荫处理下,吴茱萸的Pn日变化均呈"单峰型",并无第二峰的出现,可能与遮荫条件下,下午光强较弱,环境温度较高,空气相对湿度较低有关。     

Research and Analysis of Microorganisms in Returning the Corn Straw to Field

以玉米秸秆中木质纤维素的基本结构与组成和降解木质纤维素的微生物与酶类为依据,以解决秸秆还田过程定向快速腐熟关键技术为主,通过对微生物腐熟剂在秸秆腐解过程中定殖能力和腐解率的研究,确立了微生物腐熟剂在玉米秸秆还田中的作用,观察测试了人工加入的微生物菌群对土壤微生物种群数量及土壤酶活性的影响,对其研究测试结果进行了分析。