不同温度下扶桑绵粉蚧试验种群生命表研究(英文)

[目的]揭示温度对扶桑绵粉蚧种群动态的影响,为该虫的防治提供帮助。[方法]建立试验种群,并用棉花饲养,观察记录种群的主要参数。[结果]组建了24、27、30℃下扶桑绵粉蚧试验种群特定年龄和繁殖力特征生命表,获得了该虫世代平均历期、各虫期/年龄存活率、寿命、产卵期、单雌产卵量、性比、净增值率、内禀增长率、周限增长率、种群增长趋势指数、存活率曲线类型、日产雌量曲线类型等10余个实验种群参数,揭示了温度对该粉蚧生长发育、寿命和生殖力的影响。[结论]在适宜温度条件下,扶桑绵粉蚧繁殖潜力大,种群增长速度快,易暴发成灾。该研究结果为扶桑绵粉蚧的种群动态调查、预测预报和综合治理等提供了科学依据。     

基于Titan Image软件的QuickBird影像融合

基于北京东方泰坦科技股份有限公司研发具有完全自主知识产权的Titan Image7.0遥感图像处理软件平台,对QuickBird标准组合(全色0.61 m+多光谱2.44m)影像进行像素级融合,探讨Titan Image7.0遥感图像处理平台在影像融合及评价方面的应用.结果表明:该软件以友好的全中文界面,在同一平台上以简单的操作过程即可完成影像的融合过程与质量评价指标的求算,不仅有效的避免了跨平台、语言差异等因素带来的操作不便与信息损失,而且丰富的融合算法和质量评价指标,可以完成多种影像数据的融合和质量评价;从QuickBird影像融合与质量评价结果来看,参与融合的4种算法中以Pansharp融合算法最好,其次为小波变换算法,IHS算法、PCA算法融合效果最差,这与前人的研究结果基本一致.因此,可以认为Titan Image7.0软件是一种非常好的遥感影像融合平台.     

9个香蕉栽培品种在广西的引种试验初报

为进一步调整和优化广西的香蕉品种结构,筛选出适宜广西栽培的具有优异性状的香蕉新品种。从广东省引进9个香蕉栽培品种,并与广西主栽品种威廉斯进行比较试验,分析其生物学特性、主要农艺性状、产量和果实品质等指标。结果表明:9个引进品种的综合表现均有各自的优异特性,其中W3假茎高达271.67 cm,单株产量略高于对照威廉斯,果实品质表现最佳;W14假茎最矮,生育期比对照早24 d,果实品质好,但单株产量低于对照4.82 kg;W2、W4、W8和W12产量高,果形好,果指长,色泽光亮;W7、W9和W10风味或口感均比对照好。引进的9个香蕉栽培品种在田间的初步表现良好,具有优于当地品种的特异性状或与对照品种性状相当,值得进一步在广西示范推广。     

Oxalate-degrading capacities of lactic acid bacteria in canine feces

In this study, lactic acid bacteria in canine feces were isolated and identified, and their oxalate-degrading capacities were evaluated. The oxalate-degrading capacities were determined for 24 of 47 (51.06%) lactic acid bacteria isolates. Of these, 8 isolates [Leuconostoc mesenteroides (RL75), Lactococcus garvieae (CD2), Lactococcus subsp. lactis (CS21), Enterococcus faecium (CL71 and CL72), and Enterococcus faecalis (CD14, CS62, and CD12)] degraded more than 5% of the oxalate present, while the others degraded less than 5% of the oxalate in vitro. Isolates that degraded more than 5% of the oxalate present were selected for further examination. The oxalate-degrading capacities of individual isolates, a mixture of Enterococcus, a mixture of Lactococcus, and a mixture of the eight isolates were evaluated in media containing different concentrations of glucose (sufficient, insufficient, or no glucose). In comparison with the control medium, all of the individual isolates and mixtures of isolates could degrade oxalate in all three groups (P<0.05). In most cases, the isolates growing in medium with 20 g/L of glucose had higher oxalate-degrading capacities than those growing in medium with 2.5 g/L of glucose or no glucose. The mixture of all isolates showed higher oxalate-degrading capacity than the individual isolates and other mixtures. The oxalate-degrading capacities of the isolates were isolate dependent.     

A pig–human comparative RH map comprising 20 genes on pig chromosome 13q41 that harbours the ETEC F4ac receptor locus

The enterotoxigenic Escherichia coli (ETEC) F4ac is a major cause of diarrhoea in newborn and young pigs. The locus for the intestinal ETEC F4ac receptor (F4acR) has been mapped to pig chromosome (SSC) 13q41 with known homology to human chromosome (HSA) 3q21 and q29. However, the causative gene and mutation(s) remain unknown. The aim of this study was to characterize gene-derived markers on SSC13q41 for fine mapping of the F4acR locus, and construct a high-resolution pig–human comparative map to select positional candidate genes for F4acR. Pig-specific sequence-tagged site markers were developed for 20 genes that are located in a 6.8-Mb region on HSA3q21 and q29, and a total of 34 single-nucleotide polymorphisms (SNPs) were identified in 14 of 20 markers developed. Eighteen markers were mapped to SSC13q41, while the other two markers ( PLXNA1 and KLF15 ) were assigned to SSC13q32 and SSC7q13, respectively, by radiation hybrid mapping. This result showed that there was a small conserved segment on SSC7 corresponding to HSA3q21. A framework map comprising 18 markers on SSC13q41 was established, refining the synteny breakpoint on SSC13q41 to a region of 12.3 centiRay. The comparative radiation hybrid (RH) map revealed three interesting candidate genes for F4acR from the human genome, viz. MUC4 , MUC13 and MUC20 . Linkage analysis with six marker polymorphisms revealed that MUC4 had the most significant linkage with the F4acR locus.     

饲用油腊的加工技术及应用

本文介绍了近几年在饲料工业生产中不同饲用油脂添加技术应用及研究,重点对常规喷涂技术、真空喷涂技术和固态油脂喷雾干燥技术进行综述、分析,并对饲料中应用的固态油脂生产加工和应用技术进行了展望。     

基于信息熵的天山山区降水时空变化特征

降水是山区气候中最重要的气象要素之一,其大小及变化直接关系到干旱山区中、下游的生态环境与经济社会的发展,但是,由于技术和地理条件的限制,是难以精确观测的气象要素。本研究采用天山山区31个台站和1960-2008年间的实测降水资料,应用信息熵方法对天山山区年、季和月的降水变化特征进行分析。结果表明,天山山区降水在时间和空间上均存在变异性,时间变异性表现为信息熵的无序指数(DI)年际变化小于季节变化,季节变化小于月变化。DI多年变化特征呈现下降趋势;冬季DI变化最为显著,夏季最小;冬季北坡降水随高程的增加DI变化呈显著增加趋势(P0.05),春、夏和秋季南坡降水随高程的增加DI变化呈显著减少趋势(P0.05)。山区月降水4-9月逐渐增加,10月至次年3月降水逐渐减少,月降水DI的变化与降水变化呈反相特征。在空间上DI变化与降水的分布相反,表现为南强北弱,东强西弱,伊犁河谷降水DI变化最小。结果证明,DI方法能够有效地分析山区降水的时空变化特征,为合理开发山区的水资源提供科学依据。     

Rapid identification and differentiation of Theileria sergenti and Theileria sinensis using a loop-mediated isothermal amplification (LAMP) assay

The present study developed and validated a species-specific loop-mediated isothermal amplification (LAMP) assay for the rapid detection and discrimination of two benign bovine Theileria species – T. sergenti and T. sinensis. The LAMP assay is inexpensive and easy to perform and involves a rapid reaction-the amplification can be performed in 55 min or 50 min under isothermal conditions of 61 °C or 63 °C, respectively, by employing a set of four species-specific primer mixtures. The results can be checked using agarose gels. The optimal assay conditions, under which the assay exhibited with no cross-reaction with other closely related tick-borne parasites (T. annulata, Babesia bovis, B. bigemina, B. major, B. ovata, B. U. sp., Anaplasma marginale) or between the two Theileria species of interest, was established. The assay is approximately 10-fold more sensitive than the conventional specific PCR assay. The LAMP assay was validated using DNA from 6 standard stocks in the laboratory and was evaluated for its diagnostic utility using blood samples collected from experimentally and naturally infection cattle or yaks in China. These findings indicate that this Theileria species-specific LAMP assay may have potential clinical applications for the detection and differentiation of two benign bovine Theileria species – T. sergenti and T. sinensis, especially in endemic countries.     

菜粉蝶绒茧蜂种群空间分布型及其应用

本文应用频次分布x~2检验法,Iwao法,Taylor幂法则以及其它聚集指标等方法,分析研究了菜粉蝶绒茧蜂种群(茧块)的空间分布型。结果表明:菜粉蝶绒茧蜂茧块在甘蓝上呈聚集分布,分布的基本成分是以个体群形式存在,个体群之间是随机的,茧块的聚集是由寄主等环境因素引起的。此外,利用分布型参数确定了理论抽样数及序贯抽样。     

除草剂在作物间的选择性

自1946年开始使用2，4-D以来，化学除草以其高效、经济、快速等优点而广泛应用于现代农业生产中。不同除草剂对不同作物具有杀伤性，只有了解除草剂对作物及杂草间选择性的决定因素，才能正确使用除草剂，达到“苗活草死”的效果。除草剂在不同植物间的选择性是由多种因素决定的，其表现方式也多种多样，本文概述了其选择性的主要决定因素。