番木瓜环斑病毒株系的分子生物学方法鉴定

 以PRSV株系特异性引物对PRSV的PRSV126(PRSV日本分离物)、Ys、Vb和Sm等株系进行RT-PCR方法鉴定,引物PR21/PR22能把Ys从Vb和Sm中鉴定出来,PR300/PR301则能把Vb从Ys、Sm和PRSV126中鉴定出来;用限制性内切酶Hae Ⅱ、Sau3A I和Hinf I对PRSV的PRSV126、Ys、Vb和Sm等株系进行单酶切RT-PCR-RFLP分析,Hinf I能把PRSV126与Ys、Vb和Sm鉴别开来,Sau3A I能把Ys与Vb和Sm鉴别开来,Hae Ⅱ则能把Ys与PRSV126、Vb和Sm鉴别开来;以P1/P2为引物,对Vb、Ys和Sm株系进行RT-PCR-RFLP-SSCP分析,结果能一次把三者较好地区别开来。     

Biological control of the millet head miner Heliocheilus albipunctella in the Sahelian region by augmentative releases of the parasitoid wasp Habrobracon hebetor: effectiveness and farmers’ perceptions

On-farm augmentative releases of the parasitoid Habrobracon hebetor (Say) for controlling the millet head miner (MHM) Heliocheilus albipunctella (de Joannis) were tested in Burkina Faso, Mali and Niger from 2007 to 2009. In addition, a survey of farmers’ perceptions of insect pests, with particular focus on MHM, and the biological control program (BCP) was carried out. There was a significant increase of MHM parasitization rate after the releases, with up to 97% mortality. The survey on farmers’ perceptions revealed a fair knowledge of the MHM and the ability of farmers to describe the pest and the damage it caused. Farmers claimed that the biocontrol agent H. hebetor is effective and perceived a significant gain in grain yield due to this control strategy. Implications of these findings for a large extension of the MHM biocontrol program are discussed.     

农业生产率及其影响因素的相关分析

采用典型相关分析方法，构建了农业生产率的典型相关模型，定量判别各影响因素的变动对农业生产率的作用程度，并对计算结果进行了经济分析。     

瓜类蔬菜子叶离体培养的研究进展

本文对瓜类蔬菜子叶离体培养的研究进行综述,包括再生途径、影响因素及应用等方面研究的进展,讨论了瓜类蔬菜子叶离体培养存在的问题和今后研究的重点。     

农艺措施对大豆籽粒蛋白质和脂肪含量的影响

探讨了栽培密度、撒可富专用肥、思德富多元长效肥等农艺措施对大豆籽粒蛋白质和脂肪含量的影响。结果表明 ,密度对蛋白质含量、脂肪含量和蛋白脂肪总含量的影响不大。在各种栽培密度中 ,品种九三 97- 6 0是在 30万株 /hm2 时籽粒的蛋白质含量、脂肪含量和蛋白脂肪总含量均达到最高值 ,而对于品种九三 96 - 12 7来说 ,是在 2 5万株 /hm2 时三者达到最高。并且 ,蛋白质含量、脂肪含量及蛋白脂肪总含量对栽培密度敏感程度因品种而异。撒可富专用肥和思德富多元长效肥均使蛋白质含量增加 ,使脂肪含量降低。施用撒可富专用肥后 ,蛋白脂肪总含量变化因处理而异。施用思德富后 ,蛋白脂肪总含量有所增加。     

六盘山叠叠沟小流域4种植被土壤层水文调节功能的综合评价

深入认识和定量评价植被土壤层的水文调节功能,是干旱半干旱区生态工程建设和流域水土资源管理的重要科学依据。文中在宁夏六盘山北侧半干旱区的叠叠沟小流域,分析了4种典型植被(华北落叶松林、白桦林、沙棘灌丛和草地)100cm土层的土壤容重、持水能力和渗透性等土壤水文物理性质,运用坐标综合评定法定量评价了其土壤水文调节功能。结果表明:土壤容重(g/cm3)以沙棘灌丛(1.17)最高,白桦林、华北落叶松林和天然草地较接近(1.05~1.07);土壤总孔隙度表现为华北落叶松林(54.41%)>白桦林(53.30%)>天然草地(51.91%)>沙棘灌丛(50.11%);华北落叶松林和白桦林的蓄水性能和渗透性能要优于沙棘灌丛和草地。综合评价结果显示:白桦林地的土壤水文调节功能最强(0.0008),华北落叶松林地(0.0148)和沙棘灌丛(0.0678)次之,草地的土壤水文调节功能最差(0.2418)。     

基于改进生态足迹模型的保定市土地利用的生态安全评价

为保定市土地资源的合理开发利用提供依据,运用生态足迹模型及生态压力指数模型,研究了保定市土地利用的生态安全。结果表明:1)2002-2012年保定市土地利用生态安全水平呈下降趋势,生态压力指数年平均增长率为3.57%,2002-2003年土地利用生态系统的生态安全等级处于很不安全状态,2004年以后处于极不安全状态。经对2012年保定市区及22个县(市)安全等级进行分区,由西部山区到东部平原区的生态安全等级依次为较安全→很不安全→极不安全→较不安全。     

Marine Pseudovibrio sp. as a Novel Source of Antimicrobials

Antibiotic resistance among pathogenic microorganisms is becoming ever more common. Unfortunately, the development of new antibiotics which may combat resistance has decreased. Recently, however the oceans and the marine animals that reside there have received increased attention as a potential source for natural product discovery. Many marine eukaryotes interact and form close associations with microorganisms that inhabit their surfaces, many of which can inhibit the attachment, growth or survival of competitor species. It is the bioactive compounds responsible for the inhibition that is of interest to researchers on the hunt for novel bioactives. The genus Pseudovibrio has been repeatedly identified from the bacterial communities isolated from marine surfaces. In addition, antimicrobial activity assays have demonstrated significant antimicrobial producing capabilities throughout the genus. This review will describe the potency, spectrum and possible novelty of the compounds produced by these bacteria, while highlighting the capacity for this genus to produce natural antimicrobial compounds which could be employed to control undesirable bacteria in the healthcare and food production sectors.     

Use of LOD score technology in mapping quantitative trait loci in plants

The use of LOD score analysis developed on the basis of the maximum likelihood method for establishing genetic linkage between loci determining the manifestation of quantitative traits and molecular markers in plant genetics is examined. Experimental data on the use of this approach for revealing LOD values in higher plants for the example of mapping Brassica rapa L. populations are given.     

棉花SSR-PCR过程中聚丙烯酰胺凝胶电泳操作常见问题的解决与优化

在大批量聚丙烯酰胺凝胶电泳过程中,难免会出现条带空白、弯曲或者拖尾等各种异常现象。本文以棉花DNA为例,综述了多年实验操作中遇到的突发情况及解决方法,为广大科研工作者提供参考。