广西香蕉植物线虫病发生情况调查

作者于2009-2010年,对广西香蕉线虫病发生情况进行了实地调查,分别采集根际土壤和根系样本共253份,调查结果表明：广西香蕉主要有害线虫有根结线虫、矮化线虫、短体线虫、肾状线虫、螺旋线虫、滑刃线虫、纽带线虫、垫刃线虫和小环线虫,其中根结线虫发生最普遍也最严重,根结病指最高达60,土壤根结线虫虫口密度最高达307头/100 mL土。〖JP〗     

食线虫微生物防控病原线虫的研究

植物寄生线虫是世界范围内普遍发生的植物病害,其中尤以根结线虫、胞囊线虫最为严重。利用食线虫微生物资源开发生物杀线虫剂来防治植物病原线虫日益受到各国科研人员的重视。本文对近年来国内外食线虫微生物资源挖掘、食线虫微生物侵染线虫的机制和具杀线虫活性的次生代谢产物分离、纯化等的研究结果进行了综述,并总结分析了食线虫微生物防控植物病原线虫的成功实例。期盼为研发高效环保的植物线虫生防菌剂提供文献参考。     

广东省园林植物长针科和毛刺科线虫调查初报

2008～2010年,对广东省园林植物线虫进行调查,共采集324份样品,分离到长针科和毛刺科线虫4属10个种。其中长针科线虫7种:移去剑线虫(Xiphinema elongatum)、标明剑线虫(X.insigne)、湖南剑线虫(X.hunaniense)、巴西剑线虫(X.brasiliense)、短颈剑线虫(X.brevicollum)、荔枝长针线虫(Longi-dorus litchii)和河南长针线虫(L.henanus);毛刺科线虫3种:胼胝拟毛刺线虫(Paratrichodorus porosus)、肾形拟毛刺线虫(P.renifer)和雪松毛刺线虫(Trichodorus cedarus)。     

肾状线虫属种类鉴定和特征描述

本文记述了目前世界上认可的肾状线虫属Rotylenchulus sp.已知的10个种的重要鉴定特征、世界分布和寄主范围。这10个种包括越南肾状线虫R.anamictus,短管肾状线虫R.brevitubulus,北方贝肾状线虫R.borealis,短尾肾状线虫R.clavicaudatus,离异肾状线虫R.leptus,大囊肾状线虫R.macrodoratus,长肾状线虫R.macrosoma,微小肾状线虫R.parvus,肾形肾状线虫R.reniformis,甘蔗肾状线虫R.sacchari。     

福建省蝴蝶兰根部寄生线虫种类鉴定

为明确福建省蝴蝶兰线虫发生情况,利用改良贝尔曼漏斗法从蝴蝶兰根部及根际介质中进行分离,经形态学鉴定,共有6种植物寄生线虫双尾滑刃线虫(Aphelenchoides bicaudatus)、斯坦纳长尾线虫(Seinura steineri)、奥阿胡长尾线虫(S.oahuensis)、蘑菇滑刃线虫(A.composticola)、普通丝尾垫刃线虫(Filenchus vulgaris)和食菌茎线虫(Ditylenchus myceliophagus).优势种群是双尾滑刃线虫,其次是蘑菇滑刃线虫.     

植物抗线虫基因与抗性机理研究进展

植物寄生线虫是严重危害农业生产的一类重要病原生物,对全球作物产量造成重大损失.抗线虫基因在植物抗线虫反应中发挥重要作用,发掘抗线虫基因并培育抗线虫品种是防治线虫病害的一条有效途径.抗线虫基因的定位与克隆对解析植物抗线虫性的分子机理做出了巨大贡献,明确线虫与寄主植物之间的互作关系及抗线虫机制,可以为制定和采取更加有效的防控策略提供借鉴.     

食线虫真菌蠕虫埃斯特菌对植物寄生线虫的侵染特性

为评价食线虫真菌蠕虫埃斯特菌Esteya vermicola菌株NKF 13222的生防应用价值,采用2%水琼脂培养基平板接种法测定了该菌株对7种植物寄生线虫的诱引、黏附和侵染能力,并比较了其对不同线虫的侵染特性.结果显示,该菌株的菌丝对松材线虫、拟松材线虫、腐烂茎线虫和水稻干尖线虫均有诱引作用,而对南方根结线虫、禾谷孢囊线虫和穿刺短体线虫无诱引作用;菌株的粘性分生孢子对有诱引现象的4种线虫都能黏附,接种24 h后的黏附率达到82%～99%,对无诱引现象的3种线虫不能黏附;粘性分生孢子黏附虫体后对不同线虫的侵染力存在差异,接种7 d后的松材线虫死亡率可达98%,而拟松材线虫、腐烂茎线虫和水稻干尖线虫死亡率分别为43%、35%和9%.表明蠕虫埃斯特菌不仅是松材线虫的强内寄生真菌,而且对其它重要植物寄生线虫也具有一定的应用潜力.     

连作年限对番茄根围土壤根结线虫二龄幼虫与自由生活线虫数量的影响

 保护地连作是根结线虫为害严重的主要原因,为评估连作年限对根结线虫数量及其与土壤线虫数量关系,选择典型的不同连作时间的保护地(种植番茄),研究番茄生长期间根围土壤不同土层的根结线虫二龄幼虫(second-stage juveniles,J2)与自由生活线虫数量的动态变化。结果表明:根结线虫J2数量随连作年限增加而增多,0和5-year土壤中根结线虫数量少,平均根结线虫数为1.1和2.1条/100g干土,8、10和12-year土壤中根结线虫数量平均值分别为154.9、68.3和861.8条/100g干土;在0~30cm土层,根结线虫J2数量随土层加深而增加,主要分布在20~30cm土层。土壤自由生活线虫数量随土层的增加而增多,连作对自由生活线虫数量无显著影响。0和5-year土壤中根结线虫群体占土壤线虫总数的比例小,属稀有类群,在土壤线虫中处于稳定的群落结构状态。连作8、10和12-year的土壤中根结线虫J2为优势类群,土壤中自由生活线虫数量与根结线虫数量呈现相反的趋势,根结线虫J2占土壤线虫总数的比例增加,自由生活线虫与根结线虫J2数量的比值显著降低(P<0.05)。     

Pleurotus ostreatus对线虫作用机理的研究

 本文详细地研究了粗皮侧耳(Pleurotus ostreatus)对线虫(Panagrellus redivivus)的致病过程、线虫感病症状及菌丝与线虫的相互作用。探明了粗皮侧耳对线虫致病的实质是杀主寄生,菌丝分泌的毒素首先将线虫击倒并杀死,然后菌丝从线虫体孔侵入,或靠酶和机械力的作用从表皮侵入,最后消解、吸收和利用线虫。一般菌丝与线虫接触1~5min线虫被击倒,20~30min卵和幼虫解体,4~6h成虫死亡,12h后菌丝侵入虫体营腐生生活。菌丝也可不侵染线虫,仅靠毒素将线虫杀死,在酶的协同作用下将线虫分解,直接吸收利用线虫。若菌丝分泌的毒素不足以杀死线虫,纵然菌丝与线虫充分接触也不能侵染活线虫。试验还表明,该菌平板培养产生的毒素,除去菌丝也能杀死线虫。     

离体时间及短期贮存对三种斯氏线虫侵入率及运动能力的影响

本文研究了小卷蛾线虫、拟双角斯氏线虫、古巴斯氏线虫用大蜡螟幼虫繁殖时其脱离寄主虫体时间和离体后短期贮存对线虫侵入率及运动能力的影响。结果表明：线虫离体时间对其侵入率有一定影响,第１天离体的线虫其侵入率均大于第７天离体的线虫,这在古巴斯氏线虫中异常显著。在３０天贮存期内,３种线虫随着贮存期的延长,其侵入率逐渐提高,小卷蛾线虫和拟双角斯氏线虫一般贮存７天,古巴斯氏线虫贮存１５天,其侵入率即达到高峰,以后基本趋于稳定;经短期贮存后,除古巴斯氏线虫的运动能力无显著提高外,其它两种线虫贮存１０天后其运动能力均高于刚离体的线虫。     

植物线虫分子鉴定研究进展

植物线虫可危害农作物和林木,对它们的准确鉴定是防治植物线虫病害的基础。由于植物线虫很小,而且在形态上种间常有覆盖,而种内有较大的变异,仅依据形态特征很难鉴定。分子鉴定技术给植物线虫的检测和鉴定提供了快速、精确、可靠的方法。文章综述了植物线虫分子的DNA提取、分子鉴定靶标序列的选择及分子鉴定方法等方面的研究进展及现状,以促进对植物线虫分子鉴定更深入的研究。     

Interactions Among a Soil Organic Amendment, Nematodes, and the Nematode-Trapping Fungus Dactylellina candidum

ABSTRACT When alfalfa leaves (Medicago sativa) are added to soil, both the nematode-trapping fungus Dactylellina candidum and microbivorous nematodes increase. To determine whether the response of the fungus to alfalfa depends on consumption of bacterivorous and fungivorous nematodes, soil microcosm experiments were performed. D. candidum did not increase if alfalfa leaves were added to soil lacking nematodes, but did increase if nematodes were added to soil lacking alfalfa leaves. Although these results indicate that the response of D. candidum to alfalfa depends on nematodes, D. candidum and microbivorous nematodes did not exhibit classical predator-prey dynamics (i.e., D. candidum seldom reduced numbers of resident nematodes and, after initially increasing in alfalfa amended soil, numbers of D. candidum then decreased, whereas numbers of nematodes continued to increase). Fungivorous nematodes were abun dant in alfalfa-amended soil, and their potential to suppress trapping fungi requires more research.     

内蒙古赤峰市保护地蔬菜根结线虫种类鉴定

正根结线虫(Meloidogyne spp.)广泛分布于世界各地,是影响我国农业生产最大的一类植物病原线虫,寄主植物有3 000多种,可侵染几乎所有的蔬菜作物,其中,茄科(Solanaceae)、葫芦科(Cucurbitaceae)和十字花科(Brassicaceae)等蔬菜受害最重~([1])。常见的根结线虫种类有南方根结线虫     

甘肃酒泉甘草根际土壤线虫群落多样性研究

为明确甘肃酒泉地区甘草根际土壤线虫群落特征,于2014年7月和9月,采集甘草根际土壤,利用淘洗-过筛-蔗糖离心法分离线虫,根据线虫形态学特征进行鉴定。结果表明,从甘草根际土壤样品中共分离到植物寄生线虫1目4科5属,非植物寄生线虫4目7科16属。真滑刃属(Aphelenchus)和中杆属(Mesorhabditis)为甘草根际土壤线虫的优势属。与7月份相比,9月份甘草根际土壤线虫个体密度和类群数显著减少,多样性指数(H′)和丰富度指数(SR)降低,且丰富度指数(SR)降幅显著,均匀度指数(J′)显著高于7月份,月份间PPI/MI差异显著,表明外界环境及人类活动对甘草土壤线虫功能类群影响较大;瓦斯乐斯卡指标(WI)为6.55,且7月份显著大于9月份,表明酒泉地区土壤健康指数较高,土壤健康状况良好。     

植物寄生线虫滞育机制研究进展

植物寄生线虫防治困难与其在土壤中存活时间和抗逆能力有直接关系。休眠或滞育是其度过逆境条件或缺乏寄主时的主要策略。根据植物寄生线虫休眠或滞育的特点和规律可确定防治的关键时期。本文就植物寄生线虫休眠或滞育的影响因素和不同寄生线虫的滞育特点, 以及一些植物寄生线虫休眠或滞育生理生化机制的研究进展进行综述, 以期为植物寄生线虫的综合防治提供新的思路。     

全国口岸进境邮寄物中截获线虫的疫情分析

本文对全国口岸2003~2016年4月从邮寄物中截获的线虫进行了汇总与分析,归纳了邮寄物中截获寄生线虫的种类、来源等,结果表明,全国口岸从邮寄物中共计截获线虫42属、4 448批次,其中包括检疫性线虫11种、49批次,随着邮寄物品数量和种类的增加,邮检中线虫的截获率逐年增加。目前进境邮寄物中线虫的疫情十分复杂,应对进境苗木、植物产品、蔬菜水果等加强检疫监管,以防止线虫疫情进一步扩展。     

Profiling soil free-living nematodes in the Namib Desert,Namibia

Functional structure and diversity of soil free-living nematodes in a desert environment depend on plant gender and sampling site.The objective of this study was to compare the composition,abundance and tropic group of soil free-living nematodes in the upper 0–10 cm soil layer under the male and female Acanthosicyos horridus Welw.ex Hook.f.plants and in the inter-shrub open areas(control)in the Namib Desert,Namibia in April 2015.Soil moisture,organic matter(OM)and pH was also analyzed.Free-living nematodes were extracted from 100 g soil using the Baermann funnel procedure,and total number of nematodes was counted under a microscope.Community composition and diversity of soil free-living nematodes were analyzed using 18S rDNA sequences.Results indicated that a total of 67 groups,including 64 species,2 genera and 1 family were identified.Feeding behavior of 58 species were identified as follows:15 bacteria-feeding species,12 fungi-feeding species,10 plant-parasite species,5 omnivorous-predator species,8 animal-parasite species,5 invertebrate-parasite species and 3 non-free-living nematodes,known as marine species.Moreover,soil free-living nematodes were found to be affected by sampling locations and plant gender,and community composition and density of these nematodes were strongly influenced by soil OM content.Result confirmed that spatial location and plant cover were main factors influencing the diversity of soil free-living nematodes.Moreover,molecular tools were found to be very useful in defining the richness of soil non-free-living nematodes.In conclusion,the results elucidated the importance of biotic variables in determining the composition and abundance of soil free-living nematodes in the Namib Desert,Namibia.     

Influence of different fertilization regimes on plant-parasitic nematodes in the black soil region of Northeast China

Plant-parasitic nematodes can cause serious plant diseases and adversely affect crop production. We investigated the temporal and vertical dynamics of plant-parasitic nematodes in northeast China to determine if long-term fertilizer application suppresses the population of plant-parasitic nematodes and influences their vertical distribution in the black soil region. The long-term fertilizer application lasted for 14 years, and included three treatments: pig manure combined with chemical fertilizer (MCF), chemical fertilizer (urea and ammonium phosphate, CF), and no fertilizer (NF). A 3-year corn-wheat-soybean rotation was grown on the field site, soil samples were obtained in the corn phase and nematodes were extracted, identified and counted. Six plant-parasitic nematode genera with relative abundance over 0.1% were found in this study. Heterodera was the dominant genus in all three fertilizer treatments, and its relative abundance was highest in NF (45.4%) and lowest in MCF (32.8%). Fertilizer application had a significant effect on abundance of total soil nematodes but not on either plant-parasitic nematodes or Heterodera. Significant differences in the abundance of total soil nematodes, plant-parasitic nematodes and Heterodera were observed among soil depths and interaction of fertilizer × soil depth. Total soil nematodes were mainly distributed in the 0–20 cm soil layer, and plant-parasitic nematodes and Heterodera were mostly distributed in the 10–30 cm soil layer. Fertilizer application did not show a significant effect on plant-parasitic nematodes or Heterodera at any of the sampling depths from 0 to 80 cm. The results indicated that fertilizer has no effective control on plant-parasitic nematodes when dominant genera and their respective plant hosts exist in relatively high abundance.