Steinernema feltiae和Heterorhabditis megidis侵染前行为对其侵染力的影响

以末龄大腊螟幼虫为测试对象 ,采用Miller的一对一方法 ,研究了Steinernemafeltiae和Heterorhabditismegidis的Nictating行为、寄主刺激及活动能力对其侵染力的影响。实验证明 ,H megidis在泥炭基质上表现Nictation行为 ,但S feltiae不表现典型的Nictating行为 ,仅身体的一部分左右摇摆。H megidis表现Nictation行为或受昆虫寄主刺激线虫个体的侵染力显著高于无Nictation行为或未受昆虫寄主刺激线虫个体的侵染力 ,线虫的活动能力越强其侵染力越强 ;S feltiae线虫侵染前的身体摇摆行为和昆虫寄主的刺激对线虫的侵染力无显著影响 ;活动能力较强或活动能力较弱的线虫个体 ,侵染力要高于活动能力居中的线虫个体。     

药剂处理对重茬大棚草莓根际微生物的影响

在初果期、盛果期和采果末期3个时期,研究了3种处理（太阳能防治剂、无公害草莓重茬病防治剂、溴甲烷）对重茬大棚丰香草莓根际土壤微生物数量的影响,从根际土壤中分离筛选得到14个纯菌株并做了初步的菌属鉴定,试验结果表明：药剂处理后的土壤比对照真菌、放线菌数量减少,细菌数量增多,真菌与细菌的比值显著降低,并与果实产量有显著相关性;线虫数量的变化趋势为初果期多,盛果期、采果末期逐渐减少。     

东农L-10对大豆胞囊线虫3号生理小种的遗传模型分析

为明确非小种特异性抗病大豆种质东农L-10对大豆胞囊线虫3号生理小种的抗性遗传模式,以东农L-10为共同父本,分别以感病品种黑农37、绥农10号和绥农14为母本,构建了3个F_(2∶10)重组自交系群体,利用酸性品红染色法对3个群体进行SCN 3号生理小种的抗性鉴定,结果表明:亲本间雌虫指数均存在较大差异,群体雌虫指数符合连续正态分布,后代中抗病株系不存在显著的超亲效应。利用主基因+多基因混合遗传模型对抗性鉴定数据进行遗传模型解析,发现东农L-10对抗大豆胞囊线虫3号生理小种的抗性符合主基因+多基因遗传模型,在不同遗传背景条件下,均存在2~3个主基因控制3号生理小种的抗性,以上研究结果为挖掘东农L-10的主效抗病位点和分子辅助选育高抗SCN 3号生理小种的大豆品种提供理论依据。     

黑龙江省西部大豆胞囊线虫病发生动态及防治对策

大豆胞囊线虫病是世界大豆产区危害最重的病害之一,随着大豆重迎茬面积的增加,其发生面积也在逐年扩大,危害程度逐渐加重,使大豆产量显著降低,一般减产10%～20%,重者可达30%～50%,甚至绝产。重迎茬是导致黑龙江省西部地区孢囊线虫发病程度逐年加重的主要原因,通过合理轮作、应用抗线大豆品种、药剂防治、配方施肥等综合措施可有效地控制大豆胞囊线虫的危害。     

Effects of emission reduction surface seal treatments on pest control with shank-injected 1,3-dichloropropene and chloropicrin

The phase-out of methyl bromide for preplant soil fumigation has resulted in an increased reliance on combinations of 1,3-dichloropropene and chloropicrin in many annual and perennial cropping systems in California. However, these fumigants also can have negative environmental and human health consequences and considerable research has been conducted on methods to minimize emission of these products from the soil to the atmosphere. To ensure that pest control efficacy is not compromised by emission reduction techniques, this research was conducted to simultaneously evaluate the effects of several surface seal techniques on fumigant emissions and the efficacy of soil-borne pest control with a mixture of 1,3-dichloropropene + chloropicrin. Results indicated that the interaction between emission reduction techniques and pest control efficacy can be complicated. For example in the 2006 trial, some surviving nematodes were observed in plots with both high (manure plus high density polyethylene film) and intermediate (pre-irrigation) 1,3-D cumulative emissions which suggested that emission loses are not solely responsible for some pest control failures. Weed control tended to be better with plastic film treatments and worse with pre-fumigation soil moisture manipulations but was affected less than expected by intermittent water seals. Although pest control clearly was affected by surface seal techniques, especially in shallow soil layers, some differences in nematode and weed control could not be explained solely by surface seals. These results underline the complex interactions among soil moisture and other environmental factors, application techniques, and emission reducing surface seal treatments. As new techniques and technologies become available to reduce fumigant emissions, we recommend that research include pest control efficacy evaluations before any emerging techniques are required by regulators or implemented by growers.     

小麦禾谷孢囊线虫病危害损失研究

为了研究小麦孢囊线虫病经济阈值,制定防治对策。采用室内盆栽试验和田间试验的方法,测定了小麦孢囊线虫(cereal cyst nematode,CCN)在不同群体密度下对小麦的危害损失,建立了CCN群体密度与产量损失的回归方程。结果表明：小麦孢囊线虫为害小麦根部,影响小麦根系发育、株高、分蘖、穗粒数、千粒重等农艺性状;每克土壤中CCN卵量≤(15±2.5)时,各项指标下降不显著,产量损失＜10%;每克土壤中CCN卵量≥(30±5)时,各项指标下降显著,产量损失高达15.52%~55.01%。因此,CCN群体密度大于30卵/g土的地区,应加强防治。     

宁波地区主要出口盆景及盆栽线虫种类调查及防控对策

[目的]摸清宁波地区盆景线虫种类,以有针对性地进行线虫防控。[方法]2005～2008年,对宁波市3家主要盆景出口企业及周边的29种主要出口盆景及盆栽植物的根际土壤、栽培介质和根组织进行线虫种类调查,共采集样品142份。[结果]分离并鉴定线虫12属,发现了剑线虫属（Xiphinema sp.）、长针属（Longidorus sp.）、短体属（Pratylenehus sp.）、毛刺属（Trichodorus sp.）和拟毛刺属（Paratri-chodorus sp.）等检疫性线虫,未发现根结线虫属。提出了线虫防控措施。[结论]宁波盆景线虫种类较多,盆景出口前需要综合治理,以确保顺利出口。     

佳木斯地区土地利用方式对土壤线虫群落组成的影响

[目的]对佳木斯地区5种土地利用类型的土壤线虫群落组成进行研究。[方法]采用5点取样法取样,采用淘洗-过筛-蔗糖离心法分离线虫,同时对线虫进行科属鉴定。[结果]土壤线虫25科36属,植物寄生线虫比例较高,共有优势属为盘旋属和野外垫刃属。土壤线虫总数、植物寄生线虫和食细菌线虫数量在土地利用类型间差异在0.05水平显著,赤小豆地和玉米地线虫数量多于林地和林边湿地;盘旋属集中分布于赤小豆地和玉米地;林地和林边湿地土壤生态系统的多样性和稳定性高于玉米地。[结论]土地利用方式对土壤线虫群落组成有一定影响。     

Host-parasite soil communities and environmental constraints: Modelling of soil functions involved in interactions between plant-parasitic nematodes and Pasteuria penetrans

Nematodes belonging to the genus Meloidogyne are the most ubiquitous and widespread plant-parasitic nematodes. They occur worldwide, are polyphagous and can parasitize most cultivated plants leading to reduced crop yields. They are especially harmful in developing countries because of the lack of suitable and feasible management strategies. Among all the control practices (chemicals, physical techniques, cultural practices, resistance), the use of natural enemies as biological control agents is the most recently developed. Pasteuria penetrans which is an obligate Gram-positive, endospore-forming bacterium, is perhaps the most promising plant-parasitic nematode biocontrol agent. Despite much research conducted on prey-predator interactions (host-parasite specificity, mechanisms of attachment, field efficacy), the influence of the soil environment on host-parasite interactions is poorly understood even when the soil appears to be the key factor. Beyond common studies on the influence of climatic conditions on the attachment of endospores of P. penetrans to nematodes, more knowledge about the systemic interactions between plants, soil water dynamics, soil texture and structure, and other biota on the parasitism of nematodes by P. penetrans would improve their utilization as biological control agents. The aim of this review is to analyze the literature dealing with the influence of the soil on nematode - P. penetrans interactions in order to suggest a helpful conceptual model based on partitioning the Pasteuria population in sub-populations according to their soil habitat (dispersible and non-dispersible aggregates, microporosity, macroporosity), not all of them being available for attachment and infection on nematodes. Such concerns should be taken into account by epidemiologists for improving biological management strategies based on the use of this bacterium.     

Pharmaceutical treatments of gastrointestinal nematode infections of sheep-Future of anthelmintic drugs

Various interacting factors have been identified to explain why health plans for nematode parasite control, based on conventional epidemiological knowledge and involving pharmaceutical treatments of their sheep hosts have become unsustainable. Of these, the emergence of anthelmintic resistance has had a major impact on the economics of sheep farming, necessitating fundamental managemental changes. This review focusses on the use of anthelmintic drugs for the control of gastrointestinal nematode infections in sheep, emphasising the need to develop sustainable strategies in the face of inevitable parasite evolution in response to exposure to anthelmintic drugs and other noxious stimuli, or favourable opportunities resulting from changing animal management and climatic factors.