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.     

拟悬铃木根结线虫及其相似种的rDNA-ITS-RFLP分析

本文用特异性引物F195和V5367,对拟悬铃木根结线虫和花生根结线虫的核糖体DNA内转录间隔区（rDNA-ITS）进行了PCR扩增,扩增产物用5种限制性内切酶Taq Ⅰ、Rsa Ⅰ、Msp Ⅰ、Cla Ⅰ、HaeⅢ进行限制性片段长度多态性（RFLP）分析.Taq Ⅰ、Rsa Ⅰ、Msp Ⅰ、Cla Ⅰ酶切拟悬铃木根结线虫的rDNA-ITS扩增产物所获得限制性酶谱与花生根结线虫的限制性酶谱一致,只有HaeⅢ酶切拟悬铃木根结线虫和花生根结线虫的rDNA-ITS产物所得酶谱不同.rDNA-ITS扩增产物的HaeⅢ酶切图谱可以区分拟悬铃木根结线虫和花生根结线虫.     

Application of biochar and vermicompost against the rice root-knot nematode (Meloidogyne graminicola): an eco-friendly approach in nematode management

Journal of Plant Diseases and Protection - The rice root-knot nematode (Meloidogyne graminicola) is one of the key pests of rice (Oryza sativa L.) in irrigated and upland rice ecosystems inflicting...     

Soil application of entomopathogenic nematodes suppresses the root-knot nematode Meloidogyne javanica in cucumber

Journal of Plant Diseases and Protection - Cucumber (Cucumis sativus) cultivation in commercial greenhouses occupies an important section of vegetable production in Iran. Root-knot nematode...     

Protective effect of Dryopteris crassirhizoma extracts in the control of the root-knot nematode Meloidogyne incognita

Journal of Plant Diseases and Protection - Root-knot nematodes (Meloidogyne spp.) are among the most damaging soilborne plant parasites and are responsible for large economic losses in a wide...     

Molecular cloning and virus-induced gene silencing of MiASB in the southern root-knot nematode, Meloidogyne incognita

Root-knot nematodes (Meloidogyne spp.), cause serious damage to agricultural production worldwide. In this study, we designed special primers based on the predicted Mitochondrial ATP synthase b subunit gene (ASB) sequence to clone the same gene in M. incognita (MiASB). The identity between the cloned MiASB and the predicted MiASB was as high as 100 %. Using the tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) system, we delivered MiASB RNAi triggers to the M. incognita feeding site on tomato seedlings, resulting in significantly fewer galls on the seedlings. Sixty days after inoculation with M. incognita, the number of root galls induced on the MiASB silence-treated seedlings was reduced by 64.3 % compared to that on the control seedlings, and reduced by 64.1 % compared to that on untreated control seedlings. This study revealed the MiASB silencing had a positive effect on the control of root-knot nematodes, and MiASB may be associated with the formation of galls caused by the nematode.     

Effect of plant elicitors on the reproduction of the root-knot nematode Meloidogyne chitwoodi on susceptible hosts

Sustainable strategies for plant-parasitic nematode control are required to reduce dependence on chemical nematicides. Foliar application of various compounds can induce a systemic defence response that reduces nematode infestation. The effects of benzothiadiazole (BTH), β-aminobutyric acid (BABA), jasmonates (cis-jasmone and methyl jasmonate) and salicylic acid (SA) in the development and reproduction of the root-knot nematode Meloidogyne chitwoodi in tomato plants were assessed. The effects of BTH and of the jasmonates were further tested on potato plants. Pot assays were conducted using tomato plants cv. Tiny Tim or potato cv. Désirée treated with foliar sprays and inoculated with 300 second stage juveniles. Nematode development and reproduction were assessed 21 and 45 days after inoculation. Treatment with SA had a negative effect on nematode development in tomato plants but did not affect reproduction and methyl jasmonate treatment was the most effective in reducing nematode penetration (58 %). Nematode development was significantly affected in potato plants sprayed with cis-jasmone. Nematode penetration was reduced by 90, 67 and 81 % in plants treated with BTH, cis-jasmone and methyl jasmonate respectively, although the reproduction factor (Rf) was only significantly lower in the BTH treatment (Rf?=?7.6) when compared to the control (Rf?=?18.1). Our results suggest that both the SA and JA pathways play an important role in plant defence mechanisms against root-knot nematode development and reproduction for both plants, and should be considered in the design of integrated pest management approaches.     

Host-parasite relationships in tobacco plants infected with a root-knot nematode (<Emphasis Type="Italic">Meloidogyne incognita</Emphasis>) population from the Azores

During a nematode survey, severe infections of tobacco feeder roots and heavy soil infestations byMeloidogyne incognita race 1 were found in S. Miguel (Azores islands, Portugal). This is the first record ofM. incognita infection of tobacco in Azores. Morphology of various life stages, analysis of the esterase electrophoretic pattern and differential host tests were used for nematode characterization and identification. Nematode-induced mature galls were spherical and/or ellipsoidal and usually contained more than one female, males and egg masses with eggs. Feeding sites were characterized by the development of giant cells that contained granular cytoplasm and many hypertrophied nuclei. Giant cell cytoplasm was aggregated along a thickened cell wall. Vascular tissues within galls appeared disorganized. The relationship between the initial nematode population density and growth of tobacco plants was tested in a glasshouse experiment in which inoculum levels varied from 0 to 512 eggs and juveniles (J₂) cm⁻³ of soil. Seinhorst’s model was fitted to height and top fresh weight data of the inoculated and control plants. Tolerance limits with respect to plant height and fresh top weight of tobacco cv. ‘Erzegovina’ plants toM. incognita race 1 were estimated as 1.25 eggs and J₂ cm⁻³ of soil. The maximum nematode reproduction rate was 404.7 at an initial population density of 4 eggs and J₂ cm⁻³ of soil. http://www.phytoparasitica.org posting March 2, 2004.     

Metabolic profiling in the roots of coffee plants exposed to the coffee root-knot nematode, Meloidogyne exigua

To understand the effect of nematode Meloidogyne exigua infestation on coffee plants, resistant and susceptible coffee seedlings were inoculated with second-stage juveniles of M. exigua, and root metabolites were studied for four time intervals at 0, 24, 48 and 96 h. During this important period for parasite establishment, the concentrations of phenols, carbohydrates, amino acids and alkaloids in the roots were measured, and hydrogen nuclear magnetic resonance spectra of the root extracts were used to identify and quantify other metabolites. One of the most striking changes was the concentration of fumaric acid on resistant plants, which varied from 59 μg g(of root)^?1 to 138 μg g(of root)^?1 during the first 24 h of the nematode inoculation. The same level of variation was observed much later (96 h) in susceptible plants. Similarly, formic and quinic acid concentrations increased more rapidly in the resistant plants compared to the susceptibles. Sucrose concentrations increased to 370 % in the first 48 h in the resistant plants but showed no significant variation in the susceptible plant. Besides, the concentration of alkaloids was much higher at 24 and 48 h in the susceptibles compared to the resistant plants. These results suggest that the higher production of sucrose as well as formic, fumaric and quinic acids, and the lower production of alkaloids by the resistant cultivar in the first 48 h after the nematode inoculation are associated with the resistance of coffee plants to M. exigua.     

In vitro susceptibility of root-knot nematode populations (Meloidogyne spp.) from Crete,Greece to oxamyl and fenamiphos

Journal of Plant Diseases and Protection - Carbamate and organophosphate nematicides are routinely used for control of root-knot nematodes (RKN, Meloidogyne spp.) in greenhouses of Crete, Greece....     

First report of fig mosaic virus infecting common fig (Ficus carica) in Japan

For the first time, fig mosaic virus (FMV) was detected in common fig (Ficus carica) trees in Shimane, Japan. These trees exhibited mosaic, ringspots, or distortion, accompanied by chlorosis on leaves and yellow spots on fruits. Some of the symptomatic trees were infested with the eriophyid mite Aceria ficus. The virus was detected based on RT-PCR, followed by sequencing. The amplified 300 base-pair fragments shared 83.5–91.5% identity with the corresponding region of RNA-dependent RNA polymerase gene of FMV isolates previously reported in Turkey, Iran, and Italy.     

Control of root-knot nematodes (Meloidogyne spp.) in Hungary1

Under Hungarian climatic conditions, root-knot nematodes, and other phytoparasitic nematodes, generally cause damage in certain plant growing areas. These pests are present in glasshouses throughout the country. In the field the nematodes occur in sandy soil in the vegetable-growing areas of southern and central Hungary. The following species of root-knot nematodes have so far been reported to occur in Hungary: Meloidogyne incognita, M. arenaria, M. hapla, M. javanica, M. incognita acrita, M. thamesi and M. naasi. There are 10 specific nematicides registered for nematode control in the country. These chemicals are mainly applied in glasshouses where their use produces most economic return. Nematoderesistant cultivars are only available in the case of tomato. The nematodes cause the heaviest damage on glasshouse cucumber.