牲畜粪便与秸秆混合的厌氧发酵效果及影响因素分析

为进一步明确混合原料厌氧发酵效果及影响因素,以牛粪、鸡粪和麦秆为发酵原料,按总固体质量比分别设定了单一原料、两种及3种原料混合发酵组,分别在20℃和35℃下进行厌氧消化试验,研究了原料不同比例混合、温度、C/N比和pH值对厌氧发酵效果的影响。结果表明,原料混合发酵可显著提高总产气量、TS利用率和TS产气率;牛粪、鸡粪和麦秆3种原料混合后发酵效果显著好于单一原料以及牛粪与麦秆、鸡粪与麦秆两种原料混合的发酵效果。中温发酵效果显著好于低温发酵;牛粪、鸡粪与麦秆混合厌氧发酵的最适C/N比为25.64～27.54;混合原料发酵的pH值变化平稳且更容易维持在发酵适宜pH范围内。原料混合、温度、C/N比和pH值对厌氧发酵均有影响。     

棉花PEPC基因种子特异性ihpRNA表达载体的构建及鉴定

磷酸烯醇式丙酮酸羧化酶（phosphoenolpyruvate carboxylase,PEPC）是控制植物体中蛋白质和脂肪酸含量比例的关键酶。本研究从棉花中克隆得到船PC基因,长度为433bp,并将该基因的正反义片段分别和种子特异性启动子napin启动子（1123bp）、α球蛋白B基因启动子（1149bp）连接,插入到植物表达载体pCADS1341中。经酶切和PCR鉴定,成功的构建了PEPC基因的种子特异性ihpRNA表达载体pCADSNPSPA和pCADSBPSPA,为后期高含油量棉花材料的选育打下了基础。     

Identification of Quantitative Trait Loci for Phytic Acid Concentration in Maize Grain Under Two Nitrogen Conditions

Phytic acid(PA) is the main storage form of phosphorus(P) in seeds.It can form insoluble complexes with microelements,thereby reducing their bioavailability for animals.Identification of quantitative trait loci(QTLs) associated with grain PA concentration(PAC) is essential to improve this trait without affecting other aspects of grain nutrition such as protein content.Using a recombinant inbred line(RIL) population,we mapped QTL for grain PAC,as well as grain nitrogen concentration(NC) and P concentration(PC) in maize under two N conditions in 2 yr.We detected six QTLs for PAC.The QTL for PAC on chromosome 4(phi072-umc1276) was identified under both low-N and high-N treatments,and explained 13.2 and 15.4% of the phenotypic variance,respectively.We identified three QTLs for grain NC,none of which were in the same region as the QTLs for PAC.We identified two QTLs for PC in the low-N treatment,one of which(umc1710-umc2197) was in the same interval as the QTL for PAC under high-N conditions.These results suggested that grain PAC can be improved without affecting grain NC and inorganic PC.     

关于沙漠化概念的意见分歧及其成因浅析

科学概念对于学术交流和科学研究很重要。针对当前学术界关于沙漠化概念意见分歧很大的原因,本文查阅了大量文献,分析了学者们提出的不同沙漠化概念及其产生分歧的原因,研究结果表明：（1）沙漠化成因是沙漠化概念产生分歧的原因所在;（2）我国北方沙区曾经历过沙漠化正、逆过程的波动,其中有自然成因,也有人为成因,所以沙漠化概念不应局限在成因问题上;（3）沙漠化就是因风力而形成的沙质荒漠化。     

Effects of irrigation and nitrogen fertilization on the greenhouse gas emissions of a cropping system on a sandy soil in northeast Germany

Irrigation induces processes that may either decrease or increase greenhouse gas emissions from cropping systems. To estimate the net effect of irrigation on the greenhouse gas emissions, it is necessary to consider changes in the crop yields, the content of soil organic carbon and nitrous oxide emissions, as well as in emissions from the use and production of machinery and auxiliary materials. In this study the net greenhouse gas emissions of a cropping system on a sandy soil in northeast Germany were calculated based on a long-term field experiment coupled with two-year N₂O flux measurements on selected plots. The cropping system comprised a rotation of potato, winter wheat, winter oil seed rape, winter rye and cocksfoot each under three nitrogen (N) fertilization intensities with and without irrigation. Total greenhouse gas emissions ranged from 452 to 3503 kg CO_2-eq ha⁻¹ and 0.09 to 1.81 kg CO_2-eq kg⁻¹ yield. Application of an adequate amount of N fertilizer led to a decrease in greenhouse gas emissions compared to zero N fertilization whereas excessive N fertilization did not result in a further decrease. Under N fertilization there were no significant differences between irrigation and non-irrigation. Increases in greenhouse gas emissions from the operation, production and maintenance of irrigation equipment were mainly offset by increases in crop yield and soil organic carbon contents. Thus, on a sandy soil under climatic conditions of north-east Germany it is possible to produce higher yields under irrigation without an increase in the yield-related greenhouse gas emissions.     

1B Specific LMW-GS Primers Cloned a 1D Located Gene from Wheat Cultivar Xiaoyan 22

In the present study, one unique low-molecular-weight glutenin subunit （LMW-GS） gene. LMWXY22-2 （GenBank no. FJ028810）, was isolated from wheat cultivar Xiaoyan 22 （Triticum aestivum L.） by a pair of genomic specific PCR primers for 1B chromosome. Sequence analysis revealed that LMWXY22-2 was composed of 1 364 bp nucleotides, including a 317 bp promotion region and a 1 047 bp coding region which could be translated into a mature protein of 349 amino acids. In spite of a few minor mutations, the sequence of 5＇ untranslated region （UTR）, the coding region, the deduced N- and Cterminus comparisons indicated that LMWXY22-2 belonged to the reported subunits of LMW-m type and type lII group 5, respectively. Inner gene markers for 1D chromosome together with the phylogenetic analysis revealed that this gene was classified into Glu-D3, which was not in agreement with the I B locus-specific primers for LMW genes completely.     

小麦种质N9436抗白粉病的特异基因表达谱分析

为了解白粉菌诱导下抗白粉病小麦的抗病机制, 构建了白粉菌接种初期小麦抗性种质N9436的抑制性消减杂交文库。从文库中随机挑取140个阳性克隆, 测序结果表明, 冗余重复序列占32.86%, 其中谷胱甘肽转移酶表达频率最高, 其次为参与能量代谢的二磷酸核酮糖大小亚基。去除冗余序列和重复序列后, 得到94条EST, 利用NCBI的BLAST在线序列比对工具对GenBank的核酸和蛋白质数据库进行同源性比对和功能分析。BlastX比对结果表明, 有49条EST与已知功能蛋白同源性较高, 主要涉及抗病与防御(包括生物及非生物胁迫)、能量代谢、细胞结构、蛋白质合成及加工、转运及信号转导等过程的相关蛋白。BlastN比对NCBI的非冗余核酸数据库, 其中69条序列与EST数据库中的Unigene具有较高的同源性, 20条与EST数据库中的同源性较高, 另外5条序列找不到同源序列。通过对核酸和蛋白质同源性的比较和功能分析发现, 比对结果一致的序列有33条, 涉及白粉病抗性的相关蛋白22个, 其中与抗病信号传导相关的蛋白6个, 过敏性坏死反应(HR)体系表达蛋白2个, 系统获得性抗性(SAR)体系病程相关蛋白4个, SAR体系诱导防卫蛋白10个。     

谷子转录因子基因SibZIP42在拟南芥中对高盐和ABA的响应

【目的】分析谷子抗逆相关转录因子基因Sib ZIP42的特性和生物学功能,探讨Sib ZIP42提高植物耐盐性的调控途径,为作物抗逆分子育种提供新的候选基因。【方法】利用生物信息学方法分析谷子Sib ZIP42的特性:使用Clustal X 2.0和MEGA 5.05软件对谷子Sib ZIP42蛋白序列及其同源序列进行多序列比对,并构建系统进化树;从数据库Phytozome获取谷子Sib ZIP42上游2 000 bp作为启动子序列,在PLACE数据库对Sib ZIP42启动子顺式作用元件进行分析;使用Net Phos 2.0 Server数据库预测Sib ZIP42蛋白磷酸化位点;利用实时荧光定量PCR检测Sib ZIP42在不同胁迫条件下的表达模式;将Sib ZIP42与绿色荧光蛋白GFP融合表达,检测Sib ZIP42蛋白的亚细胞定位情况;构建植物表达载体p BI121-Sib ZIP42,转化拟南芥并检测转Sib ZIP42拟南芥的耐盐性及对ABA处理的敏感性。分析转Sib ZIP42拟南芥中ABA及脱水响应相关基因表达变化,分析Sib ZIP42调控植物耐盐性的作用机制。【结果】谷子Sib ZIP42全长546 bp,编码由181个氨基酸组成的亲水性蛋白,分子量约为20.3k D,基因编码区包含1个外显子;系统进化树分析表明该基因位于b ZIP基因家族的S亚组;Sib ZIP42与拟南芥Atb ZIP42序列同源性最高;启动子元件分析表明,Sib ZIP42包含ABRE、MYB、MYC等多种逆境胁迫应答相关元件;磷酸化位点分析结果显示Sib ZIP42含有14个丝氨酸、4个酪氨酸和1个苏氨酸磷酸化位点;实时荧光定量PCR结果显示,Sib ZIP42对多种非生物胁迫均有不同程度的响应,在高盐、干旱(PEG)和ABA处理条件下表达量明显上升,Sib ZIP42在根部的表达量显著高于在茎及叶子中的表达;亚细胞定位结果表明,Sib ZIP42蛋白定位于细胞核中;基因功能分析结果显示,在正常MS培养基上,野生型拟南芥WT和Sib ZIP42转基因拟南芥的萌发率基本一致,在Na Cl浓度为90、120和150 mmol·L~(-1)的MS培养基上,转基因拟南芥萌发率显著高于WT,在90 mmol·L~(-1) Na Cl处理条件下,转基因拟南芥的绿化率显著高于WT;在ABA浓度为0.5、1和2μmol·L~(-1)的MS培养基上,转基因拟南芥的绿化率显著低于WT;下游基因检测结果表明,HIS1-3、RD29B和RAB18等ABA胁迫响应相关基因以及脱水响应相关基因At PIP2A在转基因植株中表达量显著高于在WT中的表达,表明Sib ZIP42可能通过ABA信号途径提高植物对高盐胁迫的耐性。【结论】与WT相比,Sib ZIP42转基因拟南芥株系在种子萌发时期耐盐性显著提高。同时,在种子萌发后期Sib ZIP42转基因株系相比于WT对ABA处理的敏感性增强,Sib ZIP42可能通过ABA信号途径正向调控植物的耐盐性。     

Wnafstu棉花雄性不育系遗传类型研究

 以中棉所41、陕7359（系）、陕2089（系）、陕2234、陕024（系）5个陆地棉种质和8046-1、8046-2、8046-3三个与不育系具相同遗传背景的可育种质为测试父本,采用连续多代和多父本分别株对株测交,对西北农林科技大学发现的暂定名Wnafstu的雄性不育系进行研究。结果表明,5个陆地棉种质父本与不育系测交后,子代均为100%不育株;3个与不育株具相同遗传背景的可育株分别与不育株测交后,子代有不育和可育株两种类型,分离没有规律。据此认为,该不育系属细胞质雄性不育类型。一般陆地棉种质与其杂交,都可保持其不育性。与其具相同遗传背景的可育种质对不育系育性有恢复功能。提出了对该不育系下一步研究的方向。     

小麦抗白粉病SSH-cDNA文库中差异基因的表达模式

为了解白粉菌诱导下抗白粉病小麦的抗病机制,构建了白粉菌接种初期的抑制性消减杂交cDNA(SSH-cDNA)文库。从中随机挑取140个阳性克隆进行测序,去除冗余序列和重复序列后,得到94条EST,利用NCBI的BLAST在线序列比对工具对GenBank的蛋白质数据库进行同源性比对及功能分类。结果表明,49个EST与已知功能蛋白同源性较高,主要涉及初级代谢(2%)、能量代谢(24%)、细胞结构(2%)、转录(2%)、蛋白质合成加工与储藏(16%)、转运(4%)、信号转导(4%)和抗病与防御(30%)。经文库比较,筛选出与病程相关蛋白基因同源的EST(Z25-1)和与谷胱甘肽硫转移酶同源的EST(Z440-1),GenBank登录号为EX567369和EX567360。以其EST序列为依据设计引物,通过RT-PCR分析它们在白粉菌诱导下的表达模式,结果该2基因表达存在明显差异。其中,Z25-1在未接种白粉菌时具有一定的表达量,白粉菌侵染后表达量开始上升,侵染72 h时表达量最高,然后下降;Z440-1在未接种时也具有一定的表达量,但在接种初期表达微弱,甚至不表达,24 h后表达开始上升,到72 h时达最高,然后下降。本研究表明,病程相关蛋白和谷胱甘肽硫转移酶属于诱导型表达基因,且参与白粉病抗病反应,在白粉菌诱导72 h时表达量最高。