Physiological Variation in the Genus Meloidogyne as Determined by Differential Hosts

Four species of root-knot nematodes, namely Meloidogyne incognita (Kofoid et White) Chitwood, M. javanica (Treub) Chitwood, M. arenaria (Neal) Chitwood, and M. hapla Chitwood have a wide host-range and are widely distributed throughout the world. For each of the species there are certain non-hosts and these are different for each species, thus making it possible, through the use of differential hosts, to identify the species as well as detect pathogenic variations within a species. A knowledge of the nature and extent of this variation is needed for the development of varieties which possess a broad base for resistance.     

新疆粟罂属的研究

罂粟属(Papaver L.)植物是著名的观赏植物,花大,色泽艳丽,姿态优美,是高山植物中引人注目的花卉。本属的许多种早已被引种栽培。同时它在医药上也占有重要的地位,可从中提取多种生物碱。罂粟属是罂粟科的一个大属,属于温带分布属。全世界共有100余种。欧洲有26种;小亚细亚、苏联和西伯利亚约有六七十种;北美有十余种。罂粟属在我国主要分布于东北、华     

山药根结线虫病的发生与综合防治研究

调查研究结果表明,山药根结线虫病病原是根结线虫属(Meloidogyne)的多种根结线虫的混合群体,主要为花生根结线虫(M.arenaria)、南方根结线虫(M.incognita)和爪哇根结线虫(M.jauanica)。发病情况与山药品种、土壤质地、种植年限、山药栽子带病情况等因素有关。防治应采取综合防治的方法。     

Meloidogyne chitwoodi and Meloidogyne fallax in France: initial management experiences

Since 2008, the French NPPO has been controlling two outbreaks of Meloidogyne chitwoodi and Meloidogyne fallax, in Picardie (open fields) and in Bretagne (glasshouses). Intensive investigations have been undertaken to delimit these outbreaks and to help formulate the best control management strategy to adopt in these two very different situations. In open fields, eradication measures have been implemented, with bare fallow in infested fields being adopted as the main measure, despite the impact on affected growers and high financial cost. Recently, soil analyses in fields after 2 years of bare fallow showed that neither M. chitwoodi nor M. fallax was detected in 99% of cases, and measures have now been reduced: crops such as cereals are now allowed in these fields, but no tubers or root crops can be grown. Under glasshouses, eradication was not considered feasible and so a containment strategy was followed. An extensive national survey of susceptible crops has also been carried out for early detection of possible new outbreaks.     

我国麻黄属的分类问题

本文对我国麻黄属植物进行了分类整理,计有2组15种2变种1变型。其中增补了国内原有12种4变种的记载,同时对易于混淆的种进行了讨论。     

The Present Position in the Systematics of Meloidogyne

The genus Meloidogyne includes 32 species. The main character used for differentiation is the posterior cuticular pattern of the female. This is difficult to define and often variable but in most species it is characteristic. The body length and length and shape of the tails of the larvae, and the head characters of males, can also be used in identification of some species. The morphological and physiological variability in the commonest species is so great as to suggest that they may be species complexes or that evolution may be proceeding at an observable rate. This results in some uncertainty in the systematics.     

中国鹤虱属(Lappula Moench)分子系统学研究

以黄花软紫草(Arnebia guttata Bunge)和双柱紫草(Coldenia procumbens L.)为外类群,用PAUP*4.0 对鹤虱属(Lappula Moench)13个代表种的核糖体ITS和叶绿体rpS16序列进行分子系统发育分析。采用最大简约法和最大似然法对获得的序列矩阵进行分析,得到一致性进化树。拓扑结构显示,Lappula为单系类群,前人对该属属下阶元的划分带有一定的人为主观性,不能完全真实反映其系统发育关系。结合形态学特征,得出该属植物大致沿着花由小型到大型,果实由同型到异型,小坚果边缘有瘤或刺到具翅这样的路线演化的。     

The Place of Multiple Regression Analysis in Modern Approaches to Disease Control1)

In this paper multiple regression models are compared with fundamental models in the context of the plant disease system. The value of the regression technique for analysing the pathogen–host–environment complex and for prediction is discussed. Although there are limitations to the use and interpretation of multiple regression equations, their underlying simplicity can be of advantage for the solution of many practical problems in disease management. Despite the empirical nature of multiple regression, it can be used to advantage in the construction of hybrid models of the deductive–inductive type which combine the summary of experience with the fundamental principles of disease mechanisms.     

Detection of the root-knot nematode Meloidogyne ethiopica in Greece

Root-knot nematodes (RKN), Meloidogyne spp., are very significant in agriculture because they can be found almost everywhere and have a wide host range. In summer 2009, two soil samples from maize and kiwi crops, from the area of Kavalla in North Greece, were analyzed for the presence of nematodes. RKN were detected in both samples and identified as M. ethiopica on the basis of biochemical (esterases) and sequence data (18S rDNA). Meloidogyne ethiopica poses a significant threat to farmers in Greece and the establishment and spread of this species has to be controlled. This is the first report of M. ethiopica in Greece and the second report of this species for Europe.     

天山南北坡植物种-面积关系

通过对天山南北坡25个样地的物种-面积关系的研究,结果发现:①所有样地种-面积关系斜率的平均值为0.21±0.02,低于全球平均水平;②草甸、草原和荒漠的种-面积关系的斜率分别为0.14±0.02,0.13±0.01和0.28±0.02.草甸和草原的种-面积关系斜率无显著差别,但两者显著低于荒漠的种-面积关系斜率;③天...     

功能型复合微生物菌剂防治黄瓜根结线虫的研究

根结线虫是一类重要的土传性病原物,对露地和温室蔬菜造成严重的经济损失。本研究通过平板亲和性试验,构建出一组(淡紫拟青霉、红灰链霉菌和苍白杆菌各1株)生物兼容性好、作用方式互补的功能型复合微生物菌群;以各功能菌株发酵菌体为活性成分,研制出一种防治黄瓜根结线虫的功能型复合微生物菌剂;对该复合菌剂对黄瓜根结线虫的防效及植株生物量和产量的影响进行了评价,大田试验结果表明,施用该复合菌剂的土壤线虫扩繁指数最低;移栽后38和105 d,该复合菌剂处理的根结级数分别为2.0和4.6,对病害防效为56.5%和42.5%,效果优于10%噻唑膦处理;施用该复合菌剂可以促进植株生长、增加黄瓜产量。本研究为蔬菜根结线虫病的生物防治提供了新思路。     

Virulence of Meloidogyne incognita populations and Meloidogyne enterolobii on resistant cucurbitaceous and solanaceous plant genotypes

Journal of Plant Diseases and Protection - Root-knot nematodes (Meloidogyne spp.) cause extensive damage to tomato and cucurbit crops in protected cultivation systems. An environmentally benign...     

Host suitability and response of different vegetable genotypes to Meloidogyne incognita race 2 and Meloidogyne javanica in South Africa

The host suitability of 20 locally available genotypes of Capsicum, 10 of Daucus carota, 7 of Beta vulgaris- and 3 of Spinacea oleracea were assessed in separate greenhouse studies for resistance to Meloidogyne incognita race 2 and M. javanica, respectively. Substantial variation existed amongst the vegetable genotypes in the greenhouse screenings with regard to their host status to the respective root-knot nematode species. None of the genotypes of D. carota, B. vulgaris and S. oleracea showed resistance to the nematode species tested. However, resistance to M. incognita race 2 was identified in Capsicum genotype “Tobasco”, which was subsequently verified in a follow-up microplot trial using a range of initial population densities together with a susceptible Capsicum genotype “Paprika”. Reproduction factors of the nematodes were used as the main criterion to evaluate resistance. In the microplot trial, genotype “Tobasco” showed resistance at the lower inoculum levels but not at the higher nematode population levels. The need exists for more frequent and extensive screenings of the various vegetable genotypes in order to provide small-scale farmers with better options for improved and sustainable yields.     

Pathogenicity of the root-knot nematode Meloidogyne javanica on potato

Host–parasite relationships and pathogenicity of Meloidogyne javanica on potatoes (newly recorded from Malta) were studied under glasshouse and natural conditions. Potato cvs Cara and Spunta showed a typical susceptible reaction to M. javanica under natural and artificial infections, respectively. In potato tubers, M. javanica induced feeding sites that consisted of three to four hypertrophied giant cells per adult female. Infection of feeder roots by the nematode resulted in mature large galls which usually contained at least one mature female and egg mass. In both tubers and roots, feeding sites were characterized by giant cells containing granular cytoplasm and many hypertrophied nuclei. Cytoplasm in giant cells was aggregated alongside the thickened cell walls. Stelar tissues within galls appeared disorganized. The relationship between initial nematode population density ( P ) [0–64 eggs + second-stage juveniles (J2s) per cm³ soil] and growth of cv. Spunta potato seedlings was tested under glasshouse conditions. A Seinhorst model [ y = m  + (1 −  m ) z ^{( P − T )}] was fitted to fresh shoot weight and shoot height data of nematode-inoculated and control plants. Tolerance limits ( T ) for fresh shoot weight and shoot height of cv. Spunta plants infected with M. javanica were 0·50 and 0·64 eggs + J2s per cm³ soil, respectively. The m parameter in that model (i.e. the minimum possible y -values) for fresh shoot weight and shoot height were 0·60 and 0·20, respectively, at P  = 64 eggs + J2s per cm³ soil. Root galling was proportional to the initial nematode population density. Maximum nematode reproduction rate was 51·2 at a moderate initial population density ( P  = 4 eggs + J2s per cm³ soil).     

巴拉那根结线虫的鉴定及生物学特性

巴拉那根结线虫(Meloidogyne paranaensis)是咖啡上最具有毁灭性的根结线虫之一,可造成咖啡减产高达50%,目前主要发生在巴西、危地马拉和墨西哥,我国没有分布。本文介绍了巴拉那根结线虫的形态鉴定特征和生物学特性等内容。     

沙芥属(Pugionium Gaertn.)植物的分类

自沙芥属(Pugionium Gaertn.)建立以来,本属先后发表了5种及1变种。但就个别种或变种的存在与否及其分布问题,学术界长期以来一直存在争议。作者经查阅标本及在几种植物的主要分布区进行实地调查,通过对本属植物根、叶的形态解剖学结构及种子特性等方面比较研究,认为:本属植物共4种,即沙芥(P. cornutum Gaertn.)、斧形沙芥(P. dolabratum Maxim.)、距沙芥(P. calcaratum Kom.)和翅果沙芥(P. pterocarpum Kom.)。作者同意齿冠沙芥(P. cristatum Kom.)应与斧形沙芥合并,至于宽翅沙芥(P. dolabratum var. platypterum H. L. Yang)实际上就是翅果沙芥(P. pterocarpum Kom.),应予归并。     

生姜对南方根结线虫侵染的生理生化反应

 本试验就生姜感染南方根结线虫后几种生理生化指标的变化进行了研究.结果表明,接种南方根结线虫后,生姜体内各种生理生化指标主要在初次侵染前期和二次侵染前期表现出一定的反应,其余时间则基本丧失这种反应,且生姜不同部位对南方根结线虫侵染的反应程度也有很大差异,以叶片的反应最为剧烈,根系次之,根茎反应最弱.结合南方根结线虫的生活周期,本文提出了生姜对南方根结线虫的生理生化反应主要表现在侵染初期,对再次侵染则部分丧失敏感性的论点.     

蔬菜根结线虫病药剂防治的实践体会

近年来由于种植结构调整及一些人为因素影响,我国北方保护地蔬菜根结线虫病呈明显加重态势,已成为保护地蔬菜生产的障碍.药剂防治是目前控制蔬菜根结线虫病的主要手段,如何根据生产实际,发挥药剂防治的优势,避免负面影响,安全、有效、经济地控制根结线虫病已成为当前蔬菜生产面临的重要问题.现结合我们近几年对蔬菜根结线虫病药剂防治的实践谈几点体会,供参考.