植物寄生线虫在我国的危害特点

早在1743年Needham第一次报道线虫能寄生小麦引起粒瘿病。1850年Hardy在野燕麦上发现有另一种寄生线虫。1859年Schacht报道了寄生甜菜的线虫,1871年Schmidt对这线虫进行描述,命名为甜菜孢囊线虫(Heterodera sckachtii)。后来又有许多学者继续报道了许多植物寄生线虫,才逐渐引起人们的注意。到1906年以后便形成一门专业学科,近三十年来更进一步得到飞速发展。迄今全世界共计发现并正式描述报道的植物寄生线虫已达140多属、2000多种。 我国的植物寄生线虫研究工作起步也早,最初是1916年章祖纯在北京发现小麦线虫引起粒瘿病。50年代便在河北、天津、北京、山东     

关于植物寄生线虫俗名特点和学名汉译的再思

《经济线虫学》是本关于植物寄生线虫的教学、研究参考书;中译本为笔者所译。全书52万字,内有各种线虫名称近300个。关于植物寄生线虫学名的汉译,该书“译者的话”中有所议论。最近接读者来信,要求就那个思路,把有关问题进一步说清楚。 (一)植物寄生线虫,和其他各类动物一样,通常有两种名称,即俗名(普通名称)和学名。俗名是约定俗成的,不受任何法规约束和保护可用任何文字书写。学名则不同,其命定、修订和使用,必须遵守《国际动物学命名法规》。依法规,学名必须用拉丁文书写。这种学名,     

福建鸟类寄生饰带类线虫三新种的记述

本文报道作者近年来在福建省福州地区进行鸟类寄生线虫调查时所采集的饰带类线虫的三新种。伪树莺针形线虫,新种Acuariapseudicettiaesp.nov.寄生于毛脚燕Delichonurbica的砂囊角质层小;鸥梳旋线虫,新种Pectinospiruralarisp.nov.寄生于灰背鸥La-russchislisagus的砂囊角质层中;福建裂饰线虫,新种Schistorophusfukienensissp.nov.采自金鸻Charadriusdominicusfulvus和黑腹滨鹬Calidrisalpinasakhlina的砂囊。所有模式标本均保存于河北师范大学生物系。     

植物寄生线虫效应蛋白功能分析方法的研究进展

植物寄生线虫在侵染寄主过程中分泌许多与寄生相关的蛋白,这一类蛋白称为效应蛋白,这些效应蛋白在植物细胞内发挥各种作用,从而有利于线虫侵染、寄生和生长发育。研究这些效应蛋白的功能对于掌握线虫侵染植物的分子机理非常重要,也是寻找新的植物线虫病害防治方法的理论基础。对目前应用于研究植物寄生线虫效应蛋白功能的主要方法进行了概述。     

索线虫寄生前期幼虫的分类研究

本文对六索属、罗索属和两索属3属6种索线虫的寄生前期幼虫进行了观察比较,对索线虫寄生前期幼虫作为索科线虫属、种鉴别的可能性、分类鉴别方法和主要鉴别特征值等问题作了初步研究。     

滇金丝猴肠道寄生线虫的生防捕食线虫真菌筛选

据报道,灵长类动物体内寄生线虫感染情况严重。我国特有珍稀灵长类动物——滇金丝猴Rhinopithecus bieti肠道也受到寄生线虫感染,其健康极受影响。滇金丝猴数量稀少,极需保护。捕食线虫真菌是线虫的天敌,具较高的生防动物寄生线虫的潜力。为提供应用捕食线虫真菌生防滇金丝猴肠道寄生线虫的科学依据,本研究从滇金丝猴粪便分离捕食线虫真菌,量化测定及比较不同捕食器官类型和来自不同生境的捕食线虫真菌的捕食率,从中筛选有较高捕食率的菌株。结果显示,从滇金丝猴粪便及其他不同生境共筛选到3株捕食率较高的捕食线虫真菌菌株:Dactylellina gephyropaga(331-1),Dac.drechsleri(84-1),Drechslerella dactyloides(342-2),其捕食率分别为:81.10%,76.17%,81.33%,其中331-1分离自滇金丝猴粪便,该菌株具有高效生防滇金丝猴肠道寄生线虫的潜力;来自不同生境或同一生境同种不同株的捕食线虫真菌的捕食率差异较大;产黏性菌网的捕食线虫真菌其捕食率普遍低于产收缩环、黏性分枝和黏性球的捕食线虫真菌;捕食线虫真菌的捕食率与捕食器官生成速度呈负相关关系。     

中国淡水鱼的寄生线虫1.

关于鱼类寄生线虫的研究,在国外已有很多人做过,尤其在苏联还有特设的专门机构,进行这方面的研究,其重要性于此可以想见。我国淡水鱼的种类有五百多种,多数都是有经济价值的食用鱼,但有关寄生线虫的研究,以前虽也有不少数学者做过一些,可是与其他国家比起来则显得非常贫乏了。     

植物内生菌防治植物寄生线虫的研究进展

植物内生菌作为生物防治中的天然资源菌,已引起越来越多研究者的关注。从植物内生菌的分布和种类、分离培养、活性筛选、活性物质成分以及防治植物寄生线虫的作用机理几方面内容进行综述,并对植物内生菌防治植物寄生线虫的相关问题及发展趋势进行探讨,以期为今后深入开展相关研究提供参考。     

升金湖和菜子湖越冬白额雁肠道寄生线虫多样性研究

肠道寄生虫是鸟类中常见的病原体之一,可以传播给人类及其他动物,引起严重的人禽共患病。通过采集菜子湖和升金湖60份越冬白额雁粪便样本,以肠道寄生线虫特异引物作为标记基因进行高通量测序,分析两个湖泊越冬白额雁的肠道寄生线虫感染种类、多样性及其群落组成结构。将3299430条reads归属为肠道寄生线虫门,共定义3249个肠道寄生线虫的OTUs,鉴定到4个目,91属和191种;4个目分别为小杆目(Rhabditida)(62.12%)、垫刃目(Tylenchida)(32.20%)、疏毛目(Araeolaimida)(3.40%)和单宫目(Monhysterida)(2.27%),其中小杆目为优势物种。Shannon-wiener指数和Simpson指数显示,菜子湖越冬白额雁的肠道寄生线虫alpha多样性高于升金湖越冬白额雁,而差异性不显著, PCA聚类分析表明,两个湖泊中越冬白额雁肠道寄生线虫群落的组成结构相似。系统发育关系显示,样品与湖泊匹配度不高,部分样品分布不均匀。升金湖和菜子湖越冬白额雁的肠道寄生线虫群落群落结构相似,可能是由于食物来源相似、食性相似、栖息地环境类似等因素引起寄生虫...     

定位试验地耕层土壤植物寄生线虫空间分布特征

采用经典统计学与地统计学相结合的方法,对中国科学院沈阳生态实验站定位试验地耕层土壤中植物寄生线虫的空间分布特征进行研究。结果表明,在田间尺度下螺旋属（Helicotylenchus）、垫刃属（Tylenchus）是上下两层土壤中植物寄生线虫的优势属,矮化属（Tylenchorchychus）为下层土壤中的优势属,这3个属线虫数量占植物寄生线虫总数的92％。除下层矮化属线虫外,上下两层土壤中植物寄生线虫空间变异为48％-100％,其空间自相关范围为35～91m。克里格插值分析表明,上层土壤中植物寄生线虫总数与螺旋属线虫数量、上下层土壤中垫刃属线虫数量呈现出相似的空间分布格局。这些结果反映了不同属的植物寄生线虫沿水平和垂直方向活动性上的差异;由此可以进一步推测垫刃属和矮化属线虫向下迁移能力强于螺旋属线虫。     

Reproduction of Criconemoides simile, Helicotylenchus pseudorobustus,and Paratylenchus projectus on Soybean

Reproduction of Criconernoides simile, Paratylenchus projectus, and Helicotylenchus pseudorobustus, alone and in certain combinations, was characterized during 50 days on the soybean cultivars Custer and Hood. Custer was the more suitable host for all three nematodes and C. simile was the most vigorous parasite on both cultivars. C. simile and H. pseudorobustus reproduced as well in combination as they did alone; addition of P. projectus to this combination did not alter results. Reproduction by P. projectus was repressed on both cultivars when it was combined with C. simile and H. pseudorobustus. The relative importance of time was assessed, as it relates both to the establishment of parasitism by applied nematodes and to the rate of development of larvae in the various host-parasite combinations. The necessity of characterizing as well as enumerating populations when evaluating population development of ectoparasitic nematodes was demonstrated.     

Behavior of Tethered Meloidogyne incognita

The tethered-nematode technique was adapted for use with second-stage juveniles of Meloidogyne incognita. The data demonstrate that M. incognita exhibits the same patterns of behavior as adults of the free-living nematode, Caenorhabditis elegans. The principal differences are that M. incognita is slower and less regular in its behavior than C. elegans. The frequency of normal waves is about 0.2 Hz; that of reversal waves is about 0.06 Hz. Reversal bouts last about 1 minute. In response to a change in NaCl concentration, M. incognita modulates the probability of initiating a reversal bout in the same manner as C. elegans except that it responds more slowly and is repelled instead of attracted.     

Pathogenicity of Pratylenchus coffeae,Scutellonema bradys,Meloidogyne incognita,and Rotylenchus reniformis on Dioscorea rotundata

Low populations (200 specimens per plant) of Pratylenchus cofl''eae, Scutellonema bradys, Meloidogyne incognita, and Rotylenchulus reniformis stimulated the development of tops, roots, and tubers of Dioscorea rotundata "Guinea" yam. We demonstrated experimentally that P. coffeae was responsible for the deterioration in quality of the yam tuber in Puerto Rico, a condition known as a dry rot of yam. Initial populations of 600 P. coffeae, S. bradys, or M. incognita, and populations of 1,000 P. coffeae or S. bradys per plant were high enough to induce dry rot of the yam tubers. P. coffeae and S. bradys were pathogenic to yam cultivar Guinea, but M. incognita and R. reniformis did not cause necrosis or cracking of the tuber cortex in our experiments.     

Association of Macroposthonia xenoplax and Scutellonema brachyurum with the Peach Tree Short Life Syndrome

High populations of both Scutellonema brachyurum and Macroposthonia xenoplax were detected in the root zones of peach trees growing at sites where peach tree short life occurred. Both nematodes responded to changes in tree health, with the highest numbers detected under the most vigorous trees; both populations declined as tree vigor declined. Few of either species were detected 6 months after trees died. The nematode populations were inversely correlated with each other. More M. xenoplax were recovered during cool, wet weather, but moisture seems more important than temperature in influencing population levels. Most S. brachyurum were recovered during hot, dry weather.     

Population Development of Pratylenchus hexincisus in Eight Corn Inbreds

Of eight corn inbreds tested in the greenhouse and field, three (H60, H95, and H84) supported lower populations of Pratylenchus hexincisus than other inbreds included in this study. No apparent differences existed among inbreds in nematode invasion or development in the roots, or in population structure. Differences in population were therefore attributed to differential reproduction.     

Effect of Age of Alfalfa Root on Penetration by Pratylenchus penetrans

Penetration by all migratory life stages of Pratylenchus penetrans into roots of alfalfa (Medicago sativa L. cv. Du Puits) was inversely proportional to tissue age. Two-day-old tissue in the root hair zone was penetrated twice as much as 10- or 20-day-old sections of the tap root. Age-related differences were also observed in branch roots; these differences were not affected by increasing the number of nematodes from 1 to 10 per inoculation site, nor by increasing the length of the incubation period from 6 to 96 h. Age-related differences were only significant with 3-wk-old plants, not with 2- and 1-wk-old seedlings. Nematodes entered roots at temperatures from 5 to 30 C with maximum entry at 20 C and minimum at 5 C. At all temperatures, except 5 C, penetration into young tissue (2 days) was significantly greater than into medium (10 days) and old (20 days) tissue. Females and third-stage larvae entered the different-aged root sections 122% and 83%, respectively, more than did males. Two-day-old seedlings of the alfalfa cultivars Vernal, Saranac, and Du Puits were penetrated equally by P. penetrans. Perhaps the inverse relationship between penetration and age of root is, in part, responsible for the increasing resistance or tolerance of plants to nematode damage as they grow older.     

Interaction of Four Soybean Cultivars with Subsoiling and a Nematicide

Yields of four soybean, Glycine max, cultivars were increased with subsoiling under the row and application of the nematicide, DBCP i 1,2-dibromo-3-chloropropane) in Tiflon sandy loam heavily infested with the root-knot nematode Meloidogyne incognita. These cultivars represent four maturity groups: very early (V), "Essex'', early (VI), "Davis'': medium (VII), ''Ransom''; and late (VIII), '' Hutton ''. The average increase for the four cullivars was about the same for subsoiling or DBCP. When the treatmcnts were used together, the increase was greater than when either was used alone, but the effects were not additive. Increased yields were obtained with subsoiling and DBCP for the most nematode resistant cultivar, Hutton, as well as for the most susccptiblc, Davis. Subsoiling reduced root-knot galling in nonfumigated plots but did not affect it in fumigated plots. On 12 September, M. incognita larvae were most numerous at the 0- to 20 cm depth, intermediate at 20 to 33 cm depth and least numerous at 33 to 46 cm depth, Subsoiling did not affect larval populations at the three levels.     

Scanning Electron Micrographs of the Anterior Region of Some Species of Tylenchoidea (Tylenchida: Nematoda)

Micrographs of the anterior region of 42 species in 36 genera of Tylenchoidea obtained with a scanning electron microscope are presented. Greater detail, depth of focus, and structures not previously seen with the light microscope have been obtained in this study. Some of the implications of the morphology of the face view on the classification of the rlylenchoidca are discussed.     

The Effects of Soil Salinity and Meloidogyne javanica on Tomato

A non-sodic, non-saline sandy loam soil was salinized to anion-cation ratios similar to those naturally occurring in Iraq and California. The interactions of saline soils (conductivities 4, 8, 12 and 16 mmhos/cm) with a moderately salt-tolerant plant (Lycopersicon esculentum ''Marimond'') and a plant parasitic nematode (Meloidogyne javanica) were investigated. Plant parasitic nematodes were shown to be an important modifying influence within the plant environment, either accentuating or ameliorating salinity stress effects.