畜禽腹泻与空肠弯曲菌感染的相关性分析

对465只（头）健康和腹泻畜禽的直肠和泄殖腔拭子及108份腹泻死亡畜禽的脏器材料进行空肠弯曲菌培养,并分析畜禽腹泻与该菌感染的关系,腹泻死亡后备蛋鸡的带菌率（93．3％）明显高于腹泻后备蛋鸡（53．3％）（P＜0．005）,腹泻后备收鸡的带菌率又明显高于健康后备收鸡（22．0％）（P＜0．001）,表明后备蛋主其腹泻死亡与该菌感染相关,腹泻仔猪的带菌率很高（88．0％）也提示该菌感染与仔猪腹泻存在一定关系。在腹泻死亡畜禽肠道内,腔弯曲菌在大肠和小肠的检测出率分别为91．7％和39．0％,检出率差异极显著（P＜0．001）,即显示该菌主要感染部位可能为腹泻畜禽的大肠。351株不同动物来源空肠弯曲菌的生物学分型结果表明,分布在各种动物体的主为主（90．4％）,或其比例升高（48．1％）,健康鸡与腹泻鸡的生物型分布有差异（P＜0．05）,提示生物型Ⅱ在致畜腹泻中起一定作用,另外,同一动物体内可有该菌的2个生物型分布。     

褐飞虱不同生物型组成比例对水稻品种抗性的影响

应用二次通用旋转组合设计方法,研究了褐飞虱生物型Ⅱ和孟加拉型的不同组成比例对抗生物型Ⅱ品种IR36抗性的影响。结果表明,当孟加拉型密度比例占69.40%、生物型Ⅱ密度比例占30.04%~30.60%时会使IR36由抗虫变为感虫。     

东乡野生稻抗褐飞虱QTL分析

野生稻是水稻抗褐飞虱基因的重要种质资源。应用东乡野生稻与栽培稻协青早B构建的2套材料,开展水稻抗褐飞虱基因鉴定研究。先以协青早B//协青早B/东乡野生稻BC₁F₅群体为材料,应用褐飞虱田间种群进行抗虫鉴定,检测到2个抗褐飞虱QTL,其中,qBph2位于水稻第2染色体RM29–RG157区间,东乡野生稻等位基因可降低死苗率22.2%;qBph7位于第7染色体RM11–RM234区间,东乡野生稻等位基因可降低死苗率43.7%。进一步以协青早B为轮回亲本,构建了BC₃F₃群体,应用褐飞虱生物型I、II和III进行抗虫鉴定,QTL分析表明qBph2抗褐飞虱生物型I和II,qBph7抗褐飞虱生物型I和III。这2个QTL对培育抗褐飞虱水稻品种具有重要应用价值。     

褐飞虱不同生物型组成比例对水稻品种抗性的影响

应用二次通用旋转组合设计方法,研究了褐飞虱生物型Ⅱ和孟加拉型的不同组成比例对抗生物型Ⅱ品种IR36抗性的影响。结果表明,当孟加拉型密度比例占69.40%、生物型Ⅱ密度比例占30.04%～30.60%时会使IR36由抗虫变为感虫。     

合肥郊区番茄青枯病病原细菌致病力测定

根据细菌的形态、染色反应、生长适湿、培养性状、生理生化反应和致病性等性状的测定,将引致合肥地区番茄青枯病的病原细菌鉴定为青枯假单胞菌。并按照致病性和生理生化反应,将其定为致病性性强的小种１或生物型Ⅲ。     

The Limitations of Pulsed‐Field Gel Electrophoresis for Analysis of Yersinia enterocolitica Isolates

This study describes the analysis of 432 isolates of Yersinia enterocolitica by pulsed‐field gel electrophoresis (PFGE). PFGE had a high level of discrimination with biotype 1A isolates (Simpson's Diversity Index 0.997), but with the clinically important biotypes 2, 3 and 4, the discriminatory ability of PFGE was so low as to severely limit its usefulness (DI <0.6). For biotypes 2, 3 and 4, 79% or more of isolates of each biotype were of just three different PFGE profiles. Because of this, four known outbreaks of yersiniosis would not have been identified by PFGE analysis. However, a previously unrecognized potential outbreak of yersiniosis caused by biotype 4 isolates was identified on the basis of a rare PFGE genotype with spatial and temporal clustering. We conclude that PFGE has a very limited application to the genotyping of Y. enterocolitica biotypes 2, 3 and 4, and inferences based on finding indistinguishable PFGE profiles among cases or between cases and sources need to be substantiated using alternative typing tools, or strong epidemiological evidence.     

褐稻虱生物型的研究进展

褐稻虱生物型问题使抗虫品种的选育和利用变得十分复杂。研究生物型形成的规律,用以指导抗虫品种的选育和利用是国际上引人注目的问题。本文根据以前的研究成果,按褐稻虱生物型的发生概况、褐稻虱生物型的特异性、褐稻虱生物型的形成等3个方面进行综合整理。为今后开展这方面研究提供参考。     

武汉市攀援植物引种及应用研究

从武汉周边山野收集攀援植物野生种以及收集攀援植物栽培种共68种,对其生物学特性、生活习性等关键指标进行了观测研究。根据大田栽培观测结果,对参试攀援植物的生活型进行分类,总结了各种攀援植物的园林用途。     

Insecticide resistance in Bemisia tabaci biotype Q (Hemiptera: Aleyrodidae) from China

Dispersion of invasive biotypes of the tobacco whitefly, Bemisia tabaci, has led to protracted crop protection constraints in numerous countries over recent decades. These polyphagous, highly efficient vectors of plant viruses present an intractable problem as they frequently carry a diverse suite of insecticide resistance mechanisms. In many areas of China, native biotypes have been supplanted by the invasive and globally widespread biotype B since the 1990s. More recently, biotype Q has established, posing a new and more potent threat to agricultural production systems throughout the country. Insecticide resistance profiles for a range of Chinese B. tabaci strains covering biotypes B and Q were examined, to establish the potential for insecticides to play a pivotal role in biotype competition and ultimate displacement. Commonly used compounds including pyrethroids, neonicotinoids, abamectin and pyriproxyfen were targeted as widespread use is pre-requisite to drivers of population dynamics on a national scale.     

Differential reproductive maturity between geographically separated populations of Homalodisca vitripennis (Germar) in California

The glassy-winged sharpshooter, Homalodisca vitripennis (Germar), is native to the southeastern United States and northeastern Mexico. It was detected in southern California in the late 1980s and in the San Joaquin Valley in 1999, where it transmits the bacterium Xylella fastidiosa to grapevines and other crops. The reproductive success of hybrid and pure line H. vitripennis from two geographically separated populations in California (Riverside (RIV) and Bakersfield (BAK)) was evaluated under identical conditions. The RIV and BAK populations had different preoviposition periods that persisted through the second generation of each lineage. From adult molt, the preoviposition period in both female generations was significantly shorter for RIV (F₀ = 28.2 days and F₁ = 62.3 days) than BAK females (F₀ = 46.1 days and F₁ = 170.4 days). After a 21-day mating period, F₀ and F₁ females deposited on average 391 (range, 21–967) and 196 (range, 0–755) eggs, respectively, without significant differences in fecundity among the F₀ and F₁ mating pair treatments. Egg accumulation rates among F₁ treatments showed that females in the RIV groups rapidly deposited their eggs within the first 120 days after adult molt while BAK females maintained a steady accumulation rate during their life. The performance of both hybrid lines was intermediate between the pure lineages. The F₀ mating pairs: ♀RIV × ♂RIV, ♀RIV × ♂BAK, ♀BAK × ♂RIV, and ♀BAK × ♂BAK produced on average 185, 94, 79, and 0 viable eggs, respectively, which suggested a delayed sexual maturity of BAK males and females. The proportion of viable eggs deposited decreased gradually, which suggests that females completely exhausted sperm reserves. From a management perspective, delayed reproductive maturity and polyandry are weak links in H. vitripennis’ biology that may be exploited through mating disruption or insect sterilization strategies to reduce population growth and augment pressure by natural enemies.