Genetic analyses of resistance of the wheat differential cultivars Carstens V and Spaldings Prolific to two races of Puccinia striiformis

Genetic analysis of resistance of wheat seedlings to two races of Puccinia striiformis was conducted on F₁, F₂ and F₃ generations from crosses Carstens V (CV) × Lee, Spaldings Prolific (SPA) × Lee and CV × SPA. F₂ generations from crosses of CV and SPA with Strubes Dickkopf (SD) were also studied. The plants were classified into six resistance classes and analysed by factorial correspondence analysis and nonhierarchical classification. The two P. striiformis isolates tested were a French isolate of race 43E138 and a Lebanese isolate of race 2E16, selected for the differences in their virulence spectra for the common differential cultivars Strubes Dickkopf and Nord Desprez. Resistance of CV and SPA was recessive and dominant to races 43E138 and 2E16, respectively. CV possessed three or four resistance genes, one of them being expressed with both races. Two genes of CV had a cumulative effect for resistance to 43E138 and two or three gave dominant resistance to 2E16. SPA had three resistance genes, all of which gave resistance to 2E16 and two of which also gave resistance to 43E138. SPA had one gene in common with CV for resistance to both races. Furthermore, the gene for resistance to race 2E16 in CV and SPA was allelic with a gene in SD, and was probably Yr25 .     

饶河县森林资源动态分析

用最新的调查数据对饶河县近年来的森林资源变化情况进行了分析,并且提出了未来森林经营过程中的一些建议和措施。     

2006年《情报科学》文献计量学分析

运用文献计量学的方法,对2006年《情报科学》的载文、作者及引文进行了统计分析,研究其载文特点、作者特点及引文特点。     

援非农业技术示范中心可持续发展途径思考

中国援非农业技术示范中心陆续完成技术合作阶段,并逐步进入可持续发展期。顺利完成这个过渡期,需要前期大量的准备工作,如:中心选址、项目内容确定、专家遴选、项目设计及认真的实施过程等。     

AN INTELLIGENT BACKTRACKING METHOD FOR SOLVING COMBINATORIAL PROBLEMS

This paper proposes an intelligent method for solving a kind of intractable combinatorial problems, investigates and analyzes several important problems of this kind Theoretical and experimental results show that this method is better than the classical backtracking method.     

快速环路分解遗传算法在配电网络重构中的应用

为了有效提高配电网络的收敛速度，避免不成熟收敛，在传统遗传算法的基础上，提出了一种快速环路分解遗传算法。提出用支路的开关状态(0或1)作为控制参数，避免繁琐的编码方法，缩短了染色体的长度，同时对交叉位置的选取和变异提出了独特的方案，并用于网络重构中，极大地提高了计算效率。     

加氢反应器接管补强部位的应力分析

以应力分析法和ANSYS有限元法分别对加氢反应器接管补强部位进行了应力分析,结果表明:最大应力出现在反应器上封头与接管的内壁交界处。通过分析得知,用ANSYS软件分析反应器接管补强部位的应力比传统应力分析法更直观方便,计算相对更精确省时。     

新疆干旱区土地盐渍化信息提取及实证分析

对提取干旱区盐渍化信息的若干方法进行了评述,并且选取位于干旱区地带的盐渍化典型区域——阿克苏地区的库车、新和、沙雅县以及和田地区的于田县作为研究区进行实证分析。并采用同一时相的ETM+数据,运用K-T变换、比值变换以及通过NDVI指数和分类来提取信息发现效果明显。通过实证分析发现:虽然研究区都地处塔里木盆地周边地区,一个是塔北绿洲,另一个是塔南绿洲。但由于水文(盐渍化形成的关键)、气候(形成盐渍化土壤的驱动力)、地形(盐渍化土壤分布及差异的主要因素)、人类活动(盐渍化土壤形成的重要因素)等因素差异的存在,导致了盐渍化情况的差异。     

7株解有机磷细菌的分离和鉴定

从土壤中分离筛选出7株解有机磷的微生物。对这7株解磷细菌进行了形态、生理生化性状测定及16SrDNA序列分析(GenBankaccessionNo:S2,AY651922;S3,AY661923;X1,AY651925;Y1,AY651924;H1,AY663435;H2,AY663436andHe,AY663436)。其中S2、S3、X1和He属于假单胞菌属(Pseudomonas),Y1属于芽孢杆菌属(Bacillus),H1属于不动杆菌属(Acinetobacter),H2属于寡养单胞菌属(Stenotrophomonas)。进一步通过G C含量和DNA-DNA杂交研究,结果表明,S2、S3和X1为产碱假单胞菌(Pseudomonasalcaligenes),Y1为蜡状芽孢杆菌(Bacilluscereus)。