云南3种野生稻中抗白叶枯病基因的鉴定

白叶枯病是水稻生产上最重要的细菌性病害之一,培育抗病新品种是防治白叶枯病最经济有效的途径。然而,栽培稻来源的抗病基因数量有限,并且部分抗病基因的抗病谱窄。因此,从野生稻中发掘抗病基因,将有利于培育抗病谱广且抗病能力强的水稻新品种。本研究通过抗性鉴定和PCR分析,检测云南野生稻中的抗白叶枯病基因。结果表明,云南野生稻对2个代表性白叶枯病菌Y8和PXO99具有不同程度的抗性,疣粒野生稻甚至达到免疫的程度。功能标记检测结果显示,3种野生稻中均不含xa5、xa13和Xa21抗病基因,元江普通野生稻含Xa23和Xa3/Xa26基因或其同源基因,景洪普通野生稻中含Xa1、Xa3/Xa26和Xa27基因或同源基因,药用野生稻含Xa3/Xa26基因或同源基因,而疣粒野生稻含有Xa27抗性基因。本研究结果为进一步发掘和克隆云南野生稻中的抗白叶枯病新基因提供了理论参考。     

Self-Compatibility/Incompatibility in Some Orchids of the Subfamily Vandoideae

Self-pollination of 2f species of vandaceous orchids was followed by later embryo culture carried out to determine which species are self-compatible (SC) or incompatible (SI): 10 are SC, 1 are SI and the remaining:8 require further study. In the SI species, a few progeny could usually be recovered and these are interpreted as arising from mutation at the incompatibility locus (loci). The implications of the findings for current models of incompatibility are discussed.     

森林资源二类调查中MapInfo应用技巧探讨

MapInfo是一款著名的地理信息管理桌面系统,具有小巧灵活、使用简单、功能强大、价格适中的特点,非常适合森林资源二类调查中使用;通过合理定制工作流程、快捷键定义、快速配准、建立小班图层、MapBasic编程等技巧的应用,更能得心应手、简捷有效地处理小班信息。     

多效唑处理对蔓性千斤拔种子产量及质量的影响

目的:研究多效唑处理对蔓性千斤拔种子产量及质量的影响.方法:采用单因素随机区组试验,以多效唑喷施为因素,研究其对种子产量及质量的影响.结果:蔓性千斤拔种子产量排序为T2＞T3＞T1 ＞ck,分别较ck增加107.82％、78.52％、72.07％;而且经处理,其种子内在质量及幼苗潜在抗逆能力均高于ck.结论:适宜的多效唑处理浓度可提高蔓性千斤拔种子产量及种子质量.     

灯照控制菊花花期的问题

在生产栽培工作中,针对旧式的灯照控花方式存在的弊端,从理论上分析其科学的含量,着意从多方面去改善和革新现有的灯照控花方法,致力于提高菊花的花期控制技术.     

Bioethics. Financial conflicts get more scrutiny in clinical trials

At a national conference on clinical research last week, the incoming head of the federal government's new Office for Human Research Protections, Greg Koski, surprised his audience by suggesting that some conflicts should be avoided. His support for the idea that scientists should have no financial ties to companies whose products they are testing hints at an upcoming shift in government rules that govern the relationship between scientists and the pharmaceutical industry. But most of the discussion at the conference revolved around questions of how to "manage" conflicts rather than do away with them.     

醌氢醌的制备及其对作物生长及根系活力的影响

结果表明 :制备的醌氢醌产率达 88% ,纯度达 98% ;应用在作物上能促进花生、黄豆、小麦、甘薯以及水稻地上部和地下部的生长 ,提高其叶片叶绿素含量 ,增强根系活力 ,使豆科作物根瘤数目增加 ,有利作物生长 ;醌氢醌对作物的作用效果为 ,质量浓度为 10 mg· L-1的醌氢醌 >质量浓度为 5 mg· L-1的 >质量浓度为 0的 (CK) ;醌氢醌对水稻幼苗芽鞘生长以及根系生长的最佳质量浓度为 18- 30 mg· L-1.本文还简要探讨了醌氢醌影响作物生长的作用机理     

节灌技术在东莞市现代农业园区设计中的应用

阑述了喷灌、滴灌两种节灌技术在现代农业园区设计中的应用及其规划设计方案,并结合东莞市农业园区的实例进行介绍.     

不同水平发酵豆粕对肉鸡肠黏膜结构的影响

将1日龄艾维茵肉仔鸡240羽,随机分成4个处理,每组6个重复,每个重复10只。对照组饲喂玉米-豆粕型饲粮,试验Ⅰ、Ⅱ、Ⅲ组在饲粮中分别添加5%,10%,15%的发酵豆粕,试验共进行42d。试验结果:通过组织切片可看出,试验Ⅰ、Ⅱ、Ⅲ组的十二指肠绒毛长度和试验Ⅱ组的回肠绒毛长度与对照组比较差异显著(P<0.05);试验Ⅱ组十二指肠隐窝深度和试验Ⅰ、Ⅱ、Ⅲ组空肠隐窝深度与对照组比较差异显著(P<0.05);试验Ⅰ、Ⅱ、Ⅲ组十二指肠和试验Ⅱ、Ⅲ组回肠肠壁厚度与对照组比较差异显著;试验Ⅰ、Ⅱ、Ⅲ组的十二指肠,试验Ⅱ组的空肠,试验Ⅱ、Ⅲ组的回肠绒毛长度/隐窝深度(V/C)与对照组比较差异均显著(P<0.05)。     

Deformation on nearby faults induced by the 1999 Hector Mine earthquake

Interferometric Synthetic Aperture Radar observations of surface deformation due to the 1999 Hector Mine earthquake reveal motion on several nearby faults of the eastern California shear zone. We document both vertical and horizontal displacements of several millimeters to several centimeters across kilometer-wide zones centered on pre-existing faults. Portions of some faults experienced retrograde (that is, opposite to their long-term geologic slip) motion during or shortly after the earthquake. The observed deformation likely represents elastic response of compliant fault zones to the permanent co-seismic stress changes. The induced fault displacements imply decreases in the effective shear modulus within the kilometer-wide fault zones, indicating that the latter are mechanically distinct from the ambient crustal rocks.