深圳市观赏植物根际茎线虫的种类鉴定

在对深圳市观赏植物线虫进行调查监测的过程中,采集了长势不良的观赏植物的根和根际土壤样品,用改良贝曼漏斗法分离到植物线虫.其中从万年青(A glaonema modestum)、国王椰子(Ravenea rivularis)和袖珍椰子(Collinia elegans)的根际分离到的2种茎属线虫,经形态鉴定确认分别为食菌茎线虫(Ditylenchus myceliophagus Goodey,1958)和短小茎线虫(Ditylenchus nanus Siddiqi,1963),并对其形态和测量数值进行了详细记述.     

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.     

大豆根寄生线虫一新种

 本文描述了寄生大豆根部的一线虫新种柱尾沼泽垫刃线虫(Uliginotylenchus cylindri-caudatusn.sp.。本种线虫与U.bifascians (Andrassy) Siddiqi为近缘种,区别在于本种线虫(1)尾部无环纹;(2)口针较长(27.5μm);(3)虫体较长;(4)雄虫引带无指向背部的倒刺。这一新种是本属线虫在国内的首次报导。本文还对该属线虫的分类地位和新种与其他种的区别进行了讨论,附该属线虫分种检索表及形态特征比较表各一份。     

无锡口岸进境木质包装中截获的两种伞滑刃线虫的形态鉴定

松材线虫病是林业上的一种毁灭性病害.在进境木质包装检疫中,除该病的病原物松材线虫(Bursaphelenchus xylophilus(steiner et buhrer)Nickel)外,还常常截获同属于伞滑刃线虫属(Bursaphelenchus spp.)的多种与之形态非常相似的线虫.本研究对进境木质包装检疫中截获的两种伞滑刃属线虫--B. rainulfi和B.conicaudatus进行了形态描述和鉴定.     

草莓线虫病研究Ⅰ.江苏草莓上发生的夏矮线虫病

1986年至1987年,多次对从江苏南京和句客不同地块内采集的草莓矮缩病株地上部(大鸡冠300株,宝交早生200株和美国6号30株)进行分离,都获得同一种滑刃属线虫。经研究,这种线虫与Christie(1942)原始报道的Apbelenchoides besseyi以及从水稻干尖线虫病病种上分到的A.besseyi在形态特征上完全相同或相似,因此将其鉴定为Apbelcnchoides besseyi Cbristie,1942。对分自江苏草莓和稻种的A.bessezi进行人工培养,然后交互接种草莓和水稻,在两种线虫处理中都出现了典型的草莓矮缩和水稻干尖症状,并从有关病株内分离到与接种相同的线虫,由此证实江苏草莓夏矮病的发生。     

四种短体线虫的形态和分子生物学鉴定

采用形态学和分子生物学方法对来自荷兰的藏橐吾和铃兰、泰国的高山榕、缅甸的香蕉等种苗(球)分别鉴定出玻利维亚短体线虫Pratylenchus bolivianus、铃兰短体线虫P.convallariae、咖啡短体线虫P.coffeae和斯佩奇短体线虫P.speijeri。对这4种线虫的形态特征进行较为详细的描述后,认为头环、口针、侧区、生殖系统和尾形等形态特征是种类鉴定的重要依据;进一步利用引物28S-D2A/28S-D3Br扩增测序得到上述4种线虫的28S rRNA基因D2/D3区序列,序列分析发现玻利维亚短体线虫从欧洲到美洲的不同种群之间的遗传距离变异较小,仅为0～0.007;铃兰短体线虫同一种群不同个体之间的遗传变异较大,为0.006～0.029;咖啡短体线虫不同种群之间的平均遗传距离为0.013;斯佩奇短体线虫不同种群之间的平均遗传距离为0.010;咖啡短体线虫P.coffeae和斯佩奇短体线虫P.speijeri亲缘关系很近,二者种间平均遗传距离仅为0.026。本研究再次证明线虫28S rRNA基因D2/D3区基因序列可作为短体线虫种间鉴定的依据。     

草莓线虫病研究Ⅰ.江苏草莓上发生的夏矮线虫病

 1986年至1987年,多次对从江苏南京和句客不同地块内采集的草莓矮缩病株地上部(大鸡冠300株,宝交早生200株和美国6号30株)进行分离,都获得同一种滑刃属线虫。经研究,这种线虫与Christie (1942)原始报道的Apbelenchoides besseyi以及从水稻干尖线虫病病种上分到的A.besseyi在形态特征上完全相同或相似,因此将其鉴定为Apbelcnchoides besseyi Cbristie,1942。
对分自江苏草莓和稻种的A.bessezi进行人工培养,然后交互接种草莓和水稻,在两种线虫处理中都出现了典型的草莓矮缩和水稻干尖症状,并从有关病株内分离到与接种相同的线虫,由此证实江苏草莓夏矮病的发生。     

一种锥尾伞滑刃线虫形态和RFLP图谱变化研究

宁波口岸植检实验室在来自台湾的榕属木质包装中截获一种伞滑刃线虫,经形态学观察、测量,ITS-RFLP图谱比对及序列分析,鉴定为锥尾伞滑刃线虫(Bursaphelenchus conicaudatus Kanzaki,Tsuda&Futai,2000)。该线虫属松材线虫组,与鲍嘉伞滑刃线虫最近似。本文着重对该线虫与近似种的形态特征区别及ITS-RFLP图谱种内变化进行讨论。     

四种短体线虫的形态和分子生物学鉴定

 采用形态学和分子生物学方法对来自荷兰的藏橐吾和铃兰、泰国的高山榕、缅甸的香蕉等种苗(球)分别鉴定出玻利维亚短体线虫Pratylenchus bolivianus、铃兰短体线虫P. convallariae、咖啡短体线虫P. coffeae和斯佩奇短体线虫 P. speijeri。对这4种线虫的形态特征进行较为详细的描述后,认为头环、口针、侧区、生殖系统和尾形等形态特征是种类鉴定的重要依据;进一步利用引物28S-D2A/28S-D3Br扩增测序得到上述4种线虫的28S rRNA基因D2/D3区序列,序列分析发现玻利维亚短体线虫从欧洲到美洲的不同种群之间的遗传距离变异较小,仅为0~0.007;铃兰短体线虫同一种群不同个体之间的遗传变异较大,为0.006~0.029;咖啡短体线虫不同种群之间的平均遗传距离为0.013;斯佩奇短体线虫不同种群之间的平均遗传距离为0.010;咖啡短体线虫P. coffeae和斯佩奇短体线虫P. speijeri亲缘关系很近,二者种间平均遗传距离仅为0.026。本研究再次证明线虫28S rRNA基因D2/D3区基因序列可作为短体线虫种间鉴定的依据。     

海南岛反季节蔬菜根际寄生线虫种类记述

从海南岛反季节蔬菜根际土壤中分离鉴定出9属12种寄生线虫,分别为肾形肾状线虫(Rotylenchulus reniformis LinfordOliverira,1940)、双宫螺旋线虫[Helicotylenchus dihystera(Cobb,1893)Sher,1961]、刻尾螺旋线虫(H.crenacauda Sher,1966)、咖啡短体线虫[Pratylenchus coffeae(Zimmermann,1898)FilipjevSchuurmans Stekhoven,1941]、穿刺短体线虫[P.penetrans(Cobb,1917)Chitwood,Oteifa,1952]、尖突潜根线虫[Hirschmanniella mucronata(Das,1960)LucGoodey,1963]、异头丝尾垫刃线虫(Filenchus heterocephalus XieFeng,1996)、塞氏纽带线虫(Hoplolaimus seinhorsti Luc,1958)、燕麦真滑刃线虫(Aphelenchus avenae Bastian,1865)、类双尾滑刃线虫(Aphelenchoides parabicaudatus Shavrov,1967)、内卷滑刃线虫(A.involutus Minagawa,1992)和较小拟毛刺线虫[Paratrichodorus minor(Colbran,1956)Siddiqi,1974]。其中,异头丝尾垫刃线虫和内卷滑刃线虫为海南岛新纪录种。     

应用昆虫病原线虫防治小菜蛾的研究

小菜蛾Ｐｌｕｔｅｌｌａ ｘｙｌｏｓｔｅｌｌａ,ＤＢＭ是十字花科的重要害虫。本文应用昆虫病原线虫斯氏线虫的六个种和异小杆线虫的一个种对小菜蛾四龄幼虫进行室内测定,筛选出斯氏线虫Ｓｔｅｉｎｅｒｎｅｍａ ｃａｒｐｏｃａｐｓａｅ Ａ２４和异小杆线虫Ｈｅｔｅｒｏｒｈａｂｄｉｔｉｓ ｂａｃｔｅｒｉｏｐｈｏｒａ ８４０６为防治小菜蛾的较理想线虫种,田间小区试验也主宰了这点。     

Ionophore and Anthelmintic Activity of PF 1022A,a Cyclooctadepsipeptide,Are Not Related

PF 1022A, a 24-membered cyclooctadepsipeptide and a potent anthelmintic drug, is active against nematodes but not against arthropods. Muscle cells of Ascaris suum generate autorhythmic spikes in electrophysiological control experiments. Exposure of the worm to PF 1022A leads to flaccid paralysis and in parallel to the disappearance of these spike events. Results of such experiments in vitro were compared with those from experiments using planar lipid bilayer membranes incorporating PF 1022A, a related linear octadepsipeptide and other cyclodepsipeptides. Whereas PF 1022A acts both as an ionophore in lipid bilayers, similar to other cyclodepsipeptides like valinomycin and enniatin A, and as a paralysing drug in worms, some of the series of depsipeptides examined have only an ion carrier function, while others exhibit only nematocidal activity. It is concluded that the ion carrier property of PF 1022A is not responsible for its paralyzing effect on nematodes and that there is a specific binding site for PF 1022A in nematodes. Binding may trigger the lethal reaction cascade, which is responsible for anthelmintic activity.     

Bacterial black spot caused by <Emphasis Type="Italic">Burkholderia andropogonis</Emphasis> on <Emphasis Type="Italic">Odontoglossum</Emphasis> and intergeneric hybrid orchids

A new bacterial black spot disease was observed on Odontoglossum, Odontioda, Odontocidium, and Vuylstekeara orchids in Japan. Typical symptoms on the leaves were dark or black spots (or both) with a yellow halo. The causal agent was identified as Burkholderia andropogonis (Smith 1911) Gillis, Van Van, Bardin, Goor, Hebbar, Willems, Segers, Kersters, Heulin and Fernandez 1995. The isolates were pathogenic on four original host orchids, Phalaenopsis orchid, and tulip; they were not pathogenic on white clover or corn after needle stab inoculation. An antibiotic bactericide (oxytetracycline/streptomycin mixture WP) was most effective for controlling the disease.     

Putative new species of the genus Dickeya as major soft rot pathogens in Phalaenopsis orchid production

Bacterial soft rots are a serious limitation to the production of orchids and other horticultural plants. Here, the characterization of causative bacteria isolated from Phalaenopsis orchids showing symptoms, from a commercial production site, is reported. The most commonly isolated bacteria were identified as Dickeya spp. Partial sequencing of 16S rDNA, fliC and dnaX showed diversity among the isolates and divided the isolates into two groups, with greatest similarity to previously reported undefined Dickeya lineages from orchids (UDL‐3 and UDL‐4). Two isolates (B16, S1) were sequenced using next‐generation sequencing, which has provided draft genomes of these two isolates for further studies (Ali? et al., 2015 ). Newly developed fliC‐based lineage‐specific quantitative real‐time PCR assays were used to distinguish among the lineages and to assess their relative abundances in diseased tissues. Virulence and aggressiveness comparison tests in vivo on Phalaenopsis orchids, potato plants and witloof chicory leaves indicated high virulence and extreme maceration potential of these novel Dickeya isolates, compared to a reference panel of other Dickeya spp. Pantoea cypripedii (formerly Pectobacterium cypripedii), which has previously been reported as a soft rot pathogen of orchids, was not detected, and isolates obtained from culture collections did not cause symptoms on artificially infected Phalaenopsis orchids.     

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。     

警惕检疫性有害生物马铃薯孢囊线虫(Globodera rostochiensis和G. pallida)入侵我国

马铃薯孢囊线虫包括马铃薯金线虫Globodera rostochiensis和马铃薯白线虫G. pallida, 是马铃薯生产上危害最为严重的植物寄生线虫, 一般造成30%的产量损失, 在热带发病严重地区, 产量损失高达80%~90%, 甚至绝收?由于其危害严重性, 包括我国在内的100多个国家将其列为重要检疫性有害生物?我国目前尚无马铃薯金线虫和白线虫的发生报道, 但随着贸易全球化, 马铃薯孢囊线虫传入我国的风险日趋增高?本文主要对马铃薯孢囊线虫的发生分布?危害症状?经济损失?生物学特性?传入我国的潜在风险和预防控制措施进行综述, 旨在为防止马铃薯孢囊线虫入侵我国提供参考?     

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.     

一种对桃小食心虫高毒力的斯氏线虫Steinernema sp.(CB-2Y)

本研究在室内用“沙埋法”比较了两种斯氏属昆虫病原线虫Steinernema sp.(CB-2Y)和S.feltiae Agriotos对桃小食心虫的侵染力,结果表明CB-2Y线虫对桃小食心虫幼虫和冬茧的侵染力都高于Agriotos线虫。接线虫笫7天桃小食心虫LD50,CB-2Y组为49条线虫,而Agriotos组为158条;冬茧的LD50分别为1330条和24046条。在桃小冬茧开始活动期(6月15日)分别施用两种线虫,一个月后检查桃小食心虫成虫羽化率,CB-2Y线虫的控制效果明显优于Agriotos,在1024条线虫/桃小食心虫冬茧时(75条/cm~2),越冬代桃小食心虫的羽化率分别为8.2％和29.2％。     

Characterization of Fusarium diseases on commercially grown orchids in Hawaii

A decline of unknown aetiology has become a major problem for commercial orchid production in Hawaii, one of the primary orchid‐producing states in the USA. The major symptoms of decline include root degradation, foliar blight, pseudobulb rot and sheath rot. It was unclear whether all these symptoms are caused by the same or different pathogens, but preliminary research indicated that Fusarium species may be involved. In this study, the incidence of Fusarium species was examined across 186 plants, from 29 orchid genera and intergeneric hybrids across three islands in the state of Hawaii. The main five species associated with diseased orchids were F. proliferatum (38% of samples), F. solani (16%), F. oxysporum (16%) and two previously undescribed species (8% for both species combined). The two undescribed species were similar in appearance to F. subglutinans, and were designated FS‐A and FS‐B. Pathogenicity tests established that both F. proliferatum and FS‐B caused foliar spots, foliar blight and pseudostem rot on Dendrobium orchids, and that F. proliferatum isolates from diseased tissue of several genera could also induce symptoms on Dendrobium orchids. Although orchids have increasing importance in floriculture, relatively little is known about orchid pathogens, and previous studies focused primarily on Cymbidium and Phalaenopsis. This study provides new information concerning Dendrobium orchid pathogens and suggests a much wider host range than previously recognized for the five Fusarium species recovered from tissue with symptoms. These findings can contribute to better management of Fusarium diseases, which represent a significant challenge to orchid production in Hawaii.     

<Emphasis Type="Italic">Odontoglossum ringspot virus</Emphasis> causing flower crinkle in <Emphasis Type="Italic">Phalaenopsis</Emphasis> hybrids

A new disorder exhibiting flower crinkle on Phalaenopsis orchids bearing white flowers has been observed in Taiwan, China and Japan for several years. This disorder decreased the flower longevity and was considered as a physiological syndrome. The objective of this study was to identify and characterize the real causal agent of this new Phalaenopsis disorder. Five plants of Phalaenopsis hybrids “V3” (Phal. Yukimai × Phal. Taisuco Kochdian) with flower crinkle symptoms were collected and tested by enzyme-linked immunosorbent assay with antisera against 18 viruses. The extract of leaves and flowers from one diseased plant (96-Ph-16) reacted positively only to antiserum against Odontoglossum ringspot virus (ORSV), while those from the other four plants (96-Ph-7, 96-Ph-17, 96-Ph-18 and 96-Ph-19) reacted positively to the antisera against ORSV and Cymbidium mosaic virus (CymMV). Five ORSV isolates, one each from flowers of those five diseased Phalaenopsis orchids, were established in Chenopodium quinoa. A CymMV culture was isolated from the flowers of one of the ORSV/CymMV mix-infected Phalaenopsis orchids (96-Ph-19). To determine the causal agent of the flower crinkle disease, healthy Phalaenopsis seedlings were singly or doubly inoculated with the isolated ORSV and/or CymMV. Results of back inoculation indicated that ORSV is the sole causal agent of the crinkle symptom on petals of Phalaenopsis orchid. The CP gene of the ORSV isolates from this study shared 97.3–100% nucleotide identity and 96.2–100% amino acid identity with those of 41 ORSV isolates available in GenBank. This is the first report demonstrating ORSV as the sole virus causing flower crinkle disease on Phalaenopsis orchids.