scholarly journals A Technique for Screening Grape Germplasm for Resistance to Meloidogyne incognita

Plant Disease ◽  
2001 ◽  
Vol 85 (10) ◽  
pp. 1052-1054 ◽  
Author(s):  
P. M. Cousins ◽  
M. A. Walker
Keyword(s):  
Vitis Vinifera ◽  
Meloidogyne Incognita ◽  
Nematode Resistance ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Egg Masses ◽  
Nematode Eggs ◽  
Highly Correlated

A technique to evaluate the root-knot nematode resistance of grape seedlings was developed. Seedlings of rootstock crosses and nematode-susceptible Vitis vinifera cvs. Colombard and Carignane were inoculated with Meloidogyne incognita juveniles. Reproduction of nematodes on individual plants was measured by counting the number of egg masses stained with eosin and the number of eggs present. Egg mass counts were highly correlated with egg counts. Resistant and susceptible cultivars could be clearly distinguished by the number of egg masses produced on vegetatively propagated cuttings. It is concluded that egg mass counting can substitute for the more laborious and time-consuming methods of counting nematode eggs or juveniles in the evaluation of root-knot nematode resistance in Vitis.

scholarly journals Investigating the in vitro and in vivo nematicidal performance of structurally related macrolides against the root-knot nematode, Meloidogyne incognita

2019 ◽  
Vol 12 (1) ◽  
pp. 24-37
Author(s):  
M.A. Radwan ◽  
A.S.A. Saad ◽  
H.A. Mesbah ◽  
H.S. Ibrahim ◽  
M.S. Khalil
Keyword(s):  
Meloidogyne Incognita ◽  
Root Length ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Egg Hatching ◽  
Shoot Height ◽  
Egg Masses ◽  
New Family

Summary Avermectins and spinosyns are structurally related natural products of microbial origin and belong to a new family of macrolides which are active against a vast array of invertebrate pests. In the present study, the effects of four members of macrolides; abamectin (ABM), emamectin benzoate (EMB), spinosad (SPI) and spinetoram (SPIT), on Meloidogyne incognita were investigated under in vitro and in vivo conditions. All compounds reduced egg hatching and led to high mortality of the nematode second-stage juveniles (J2). ABM showed the maximum rate of egg hatching inhibition and J2 mortality while SPIT recorded the minimum. All treatments reduced the number of galls, egg masses, eggs/egg mass in roots and J2 in the soil when compared to the control. Based on the 10 folds of the 24 h-LC50 values of J2 mortality in vitro, EMB and ABM exhibited higher percent reduction in galls (79.68 and 71.45%), egg masses (75.19 and 70.54%), eggs/egg mass (60.49 and 40.91%) and J2 in the soil (90.31 and 86.54%), respectively, compared to SPI and SPIT. Significant increase in tomato shoot height occurred in all biopesticides (10 folds) and SPIT (20 folds). SPI at 10 folds of the 24 h-LC50 values of J2 mortality in vitro, significantly increased root length while ABM at 50 folds and SPIT at 20 folds decreased root length by 5.15% and 5.88%, respectively, compared to the untreated inoculated plants. In all treatments, the dry shoot and root weights increased, compared to the untreated control. Our findings suggest that these macrolides have the ability to regulate nematode population densities and may be an alternative to classical nematicides.

scholarly journals Root-knot Nematode Resistance in Cucumis Species

HortScience ◽  
1997 ◽  
Vol 32 (5) ◽  
pp. 880-881 ◽  
Author(s):  
Perry E. Nugent ◽  
P.D. Dukes
Keyword(s):  
Cucumis Melo ◽  
Gulf Coast ◽  
Nematode Resistance ◽  
The United States ◽  
Economic Losses ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Inoculum Level ◽  
Resistant Species ◽  
Nematode Eggs

The southern root-knot nematode, Meloidogyne incognita [(Kofoid & White) Chitwood], causes serious economic losses to melon (Cucumis melo L.) production in the United States. The present study was conducted to determine if separable differences in nematode resistance of Cucumis melo could be found at some inoculum level. Five C. melo lines were compared with Cucumis metuliferus Naud. (C701A), a highly resistant species, for root necrosis, galling, egg mass production, and reproduction when inoculated at 0, 500, 1000, 2000, or 5000 nematode eggs per plant. Using these criteria, melon line C880 inoculated with 1000 eggs per plant was highly susceptible, while PI140471, PI 183311, and the cultivars Chilton, Georgia 47, Gulf Coast, Planters Jumbo, and Southland were less susceptible. In greenhouse tests with an inoculum level of 1000 eggs per plant, low levels of resistance were evident. A thorough screening of the available germplasm against M. incognita may identify higher levels of root-knot nematode resistance for incorporation into improved melon cultivars.

scholarly journals Effect of Meloidogyne incognita Inoculum Density and Application Rate of Paecilomyces lilacinus Strain 251 on Biocontrol Efficacy and Colonization of Egg Masses Analyzed by Real-Time Quantitative PCR

2011 ◽  
Vol 101 (1) ◽  
pp. 105-112 ◽  
Author(s):  
S. Kiewnick ◽  
S. Neumann ◽  
R. A. Sikora ◽  
J. E. Frey
Keyword(s):  
Real Time ◽  
Meloidogyne Incognita ◽  
Quantitative Polymerase Chain Reaction ◽  
Application Rate ◽  
Paecilomyces Lilacinus ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Inoculum Level ◽  
Egg Masses ◽  
Biocontrol Efficacy

The fungal biocontrol agent, Paecilomyces lilacinus strain 251 (PL251), was evaluated for its potential to control the root-knot nematode Meloidogyne incognita on tomato at varying application rates and inoculum densities. Conversely to previous studies, significant dose-response relationships could not be established. However, we demonstrated that a preplanting soil treatment with the lowest dose of commercially formulated PL251 (2 × 105 CFU/g soil) was already sufficient to reduce root galling by 45% and number of egg masses by 69% when averaged over inoculum densities of 100 to 1,600 eggs and infective juveniles per 100 cm3 of soil. To determine the role of colonization of M. incognita egg masses by PL251 for biocontrol efficacy, a real-time quantitative polymerase chain reaction (PCR) assay with a detection limit of 10 CFU/egg mass was used. Real-time PCR revealed a significant relationship between egg mass colonization by PL251 and the dose of product applied to soil but no correlation was found between fungal density and biocontrol efficacy or nematode inoculum level. These results demonstrate that rhizosphere competence is not the key mode of action for PL251 in controlling M. incognita on tomato.

Identification of common bean (Phaseolus vulgaris) genotypes having resistance against root knot nematode Meloidogyne incognita

2015 ◽  
Vol 38 (5) ◽  
Author(s):  
Refik Bozbuga ◽  
H. Yildiz Dasgan ◽  
Yelderem Akhoundnejad ◽  
Mustafa Imren ◽  
Halil Toktay ◽  
...  
Keyword(s):  
Common Bean ◽  
Meloidogyne Incognita ◽  
Resistance Index ◽  
Egg Mass ◽  
Yield Losses ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Resistance Response ◽  
Parental Material ◽  
Moderately Resistant

Root knot nematodes (<italic>Meloidogyne</italic> spp.) cause immense yield losses in crops throughout the world. Use of resistant germplasms of plants limits the root knot nematode damages. In this study, 87 common bean (<italic>Phaseoulus vulgaris</italic> L.) genotypes were screened against the root knot nematode, <italic>Meloidogyne incognita</italic> to determine the resistance response under growth chamber conditions in Turkey. <italic>P. vulgaris</italic> genotypes were evaluated based on resistance index (RI); root galling severity and nematode egg mass production on a 1-9 scale. The nematode negatively influenced the growth (fresh weight) of bean genotypes. At the completion of the study, 13 bean genotypes were found as immune (Sehirali), highly resistant (TR42164, Seleksiyon 5, Seker Fasulye, Fas-Agadir-Suk-1) and moderately resistant (Acik Badem, TR68587, TR43477, TR53827, TR28018, Gülnar-3, Siyah Fasulye, Kibris Amerikan) against <italic>M. incognita</italic> thus suggesting the use of such genotypes in breeding studies as a parental material to develop the root knot nematode resistant cultivars.

scholarly journals Resistance to the Peanut Root-Knot Nematode (Meloidogyne arenaria) in Arachis hypogaea1

1992 ◽  
Vol 19 (1) ◽  
pp. 35-37 ◽  
Author(s):  
C. Corley Holbrook ◽  
James P. Noe
Keyword(s):  
Egg Production ◽  
Economic Losses ◽  
Egg Mass ◽  
Root Weight ◽  
Meloidogyne Arenaria ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Plant Introductions ◽  
Nematode Eggs ◽  
Fresh Root

Abstract The peanut root-knot nematode [Meloidogyne arenaria (Neal) Chitwood race 1] causes significant economic losses throughout the peanut (Arachis hypogaea L.) production area of the southern United States. Chemicals for control of this pest are becoming increasingly limited, and there are no known sources of resistance within the U. S. A. hypogaea collection. The objectives of this research were to screen 1,321 plant introductions for resistance or hypersusceptibility based on egg-mass ratings in greenhouse tests and to conduct more intensive greenhouse studies of selected genotypes to evaluate this method for identifying resistance to the peanut root-knot nematode. Twenty-seven genotypes with low and eight genotypes with high egg-mass ratings were selected and reevaluated in a more intensive greenhouse experiment. Seventeen of the low selections supported fewer (P≤0.05) egg masses, and seven supported less egg production per gram of fresh root weight than Florunner. Three selections for high egg-mass ratings supported more nematode eggs per plant than the cultivar Florunner and had a greater host efficiency. One of these genotypes supported more nematode eggs per gram of fresh root weight than Florunner. These results show that resistance to M. arenaria exists in the cultivated peanut species and can be selected by rating egg-mass production on greenhouse-grown plants.

scholarly journals Estimation of avoidable losses caused by Meloidogyne incognita infecting cucumber in poly-house

2021 ◽  
Vol 2 (1) ◽  
pp. 35-40
Author(s):  
Shakti Singh Bhati ◽  
B. L. Baheti
Keyword(s):  
Meloidogyne Incognita ◽  
Agricultural Land ◽  
Egg Mass ◽  
Root Knot Nematode ◽  
Cucumis Sativus L ◽  
Continuous Increase ◽  
Daily Diet ◽  
Protected Cultivation ◽  
Meloidogyne Spp ◽  
Present Trial

Cucumber (Cucumis sativus L.) is a high nutritious and mineral-rich vegetable, which occupies a prominent place as a salad and vegeta-ble. It is being used in many ways in the daily diet of humans and widely cultivated worldwide. The decrease of agricultural land, ad-verse environmental conditions and continuous increase of popula-tion, the demand of nutritious food is a matter of great concern to the world. Protected cultivation is a very effective tool to solve this problem because in this cultivation the productivity of crops is very high as compared to open field conditions. High value crops suc-cessfully grown in protected cultivation, specially vegetables (cu-cumber, tomato, Capsicum etc.) which are highly susceptible to the numerous pests and pathogens, including phyto-parasitic nema-todes (specially root-knot nematode, Meloidogyne spp.). With this view, present trial was taken to estimate the avoidable losses caused by Meloidogyne incognita infecting cucumber in poly-house situated on farmer’s field with the application of phorate at 2 kg a.i. ha-1 over check. Results exhibited that application of chemical treatment significantly reduced number of galls per 5 g roots, egg masses per 5 g roots, eggs & juveniles per egg mass and final nema-tode population 79.03, 81.10, 30.91 and 56.54%, respectively. Avoidable yield losses were recorded to the tune of 66.84% on cu-cumber by M. incognita in poly-house.

scholarly journals Heritability of Root-knot Nematode (Meloidogyne spp.) Resistance in Sweetpotatoes

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 622a-622 ◽  
Author(s):  
W. R. Maluf ◽  
S. M. Azevedo ◽  
V.P. Campos
Keyword(s):  
Meloidogyne Incognita ◽  
Meloidogyne Javanica ◽  
Broad Sense Heritability ◽  
Root Knot Nematode ◽  
Egg Masses ◽  
Substrate Removal ◽  
Meloidogyne Spp ◽  
Diverse Origin ◽  
Race 2 ◽  
Resistant Genotypes

Heritabilities for resistance to root knot nematodes (Meloidogyne javanica and Meloidogyne incognita races 1, 2, 3, and 4) were studied in a population of 226 sweetpotato clones of diverse origin. For each nematode isolate tested, 128-cell speedling trays were filled with previously inoculated substrate (30000 eggs/1000 mL substrate). Sweetpotato clones suitably tagged and identified were randomly planted in the cells (one plant/cell), with a total of four plants per clone per isolate. Ninety days after inoculation, sweetpotato plants had their roots washed for substrate removal, and treated with 150 mg·L–1 Phloxine B to stain nematode egg masses. The number of egg masses per root was recorded, and plants were accordingly assigned scores from 0 (highly resistant) to 5 (highly susceptible). Broad-sense heritability estimates were 0.87, 0.91, 0.81, 0.95, and 0.93 respectively for resistance to M. javanica and races 1, 2, 3, and 4 of M. incognita. The frequencies of resistant genotypes were higher for M. javanica and lower for M. incognita race 2. Genotypic correlations (rG) among the resistances to the various Meloidogyne isolates utilized were weak, ranging from 0.11 to 0.57, suggesting independent genetic controls. Clones could be selected, however, with high levels of resistance to all nematode isolates tested. (This work was supported by CNPq, CAPES, FAPEMIG, and FAEPE/UFLA.)

scholarly journals Eco-friendly based Integrated Management Practice against Root-Knot Nematode, Meloidogyne incognita on Cluster bean (Cyamopsis tetragonoloba L.)

2021 ◽  
Author(s):  
Chandra Prakash Nama ◽  
B.L. Baheti
Keyword(s):  
Ascorbic Acid ◽  
Salicylic Acid ◽  
Meloidogyne Incognita ◽  
Management Practice ◽  
Nematode Population ◽  
Egg Mass ◽  
Cyamopsis Tetragonoloba ◽  
Root Knot Nematode ◽  
Cluster Bean ◽  
Neem Leaves

Abstract AimThe experiment was carried out during two consecutive Kharif seasons to test the combined efficacy of biochemicals i.e. salicylic acid, ascorbic acid and L-arginine each at 2 % w/w as seed treatment and botanicals viz. neem, lantana and parthenium leaves powder each at 5 g per plant for the management of root-knot nematode, Meloidogyne incognita infecting cluster bean..Method All treatments applied as soil application at the time of sowing. Before sowing observation on initial nematode population/100 cc soil and at the termination of experiment number of galls/plant, number of egg masses/plant, number of eggs and larvae/egg mass, final nematode population/100 cc soil and yield (q/ha) were recorded. ResultAmong different combinations, minimum nematode population were observed with ascorbic acid at 2 per cent w/w + neem leaves powder at 5 g per plant followed by ascorbic acid at 2 per cent + lantana leaves powder at 5 g per plant and salicylic acid at 2 per cent + neem leaves powder at 5 g per plant.Conclusion: Results of experiment showed that application of biochemicals along with botanicals significantly reduced galls per plant as compared to untreated check.

scholarly journals Nematicidal activity of a biopolymer chitosan at different molecular weights against root-knot nematode, Meloidogyne incognita

2012 ◽  
Vol 48 (No. 4) ◽  
pp. 170-178 ◽  
Author(s):  
M.S. Khalil ◽  
M.E.I. Badawy
Keyword(s):  
Molecular Weight ◽  
Meloidogyne Incognita ◽  
Nematicidal Activity ◽  
Egg Mass ◽  
Low Molecular Weight ◽  
Root Knot Nematode ◽  
Molecular Weights ◽  
Tomato Seedlings ◽  
Low Molecular Weight Chitosan

The nematicidal activity of four molecular weights (2.27 &times; 10<sup>5</sup>, 3.60 &times; 10<sup>5</sup>, 5.97 &times; 10<sup>5</sup>, and 9.47 &times; 10<sup>5</sup> g/mol) of a biopolymer chitosan was assayed against the root-knot nematode, Meloidogyne incognita, in vitro and in pot experiments. In laboratory assays, the nematode mortality was significantly influenced by exposure times and chitosan molecular weight. Low molecular weight chitosan (2.27 &times; 10<sup>5</sup> g/mol) was the most effective in killing the nematode with EC<sub>50</sub> of 283.47 and 124.90 mg/l after 24 and 48 h of treatment, respectively. In a greenhouse bioassay, all the compounds mixed in soil at one- and five-fold concentrations of the LC<sub>50</sub> value significantly reduced population, egg mass, and root galling of tomato seedlings compared with the untreated control. In general, the nematicidal activity of these compounds was increased dramatically with a decrease in the molecular weight. The results suggest that the chitosan at low molecular weight may serve as a natural nematicide

scholarly journals Suppression of Meloidogyne incognita by the Entomopathogenic Fungus Lecanicillium muscarium

Plant Disease ◽  
2018 ◽  
Vol 102 (5) ◽  
pp. 977-982 ◽  
Author(s):  
Manzoor Hussain ◽  
Miloslav Zouhar ◽  
Pavel Ryšánek
Keyword(s):  
Meloidogyne Incognita ◽  
Entomopathogenic Fungus ◽  
Biocontrol Agent ◽  
Systemic Resistance ◽  
Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Egg Hatching ◽  
Positive Effects ◽  
Lecanicillium Muscarium ◽  
Nematode Eggs

The entomopathogenic fungus Lecanicillium muscarium (Petch) Zare and Gams is currently being developed as a biocontrol agent against insect pests, as well as some plant-pathogenic fungi and bacteria. Data about its activity against plant-parasitic nematodes exist, but are relatively limited. To expand this understanding, we investigated the biocontrol efficiency of three isolates of L. muscarium (Lm) against the root knot nematode, Meloidogyne incognita, in both in vitro and in vivo conditions. In our experiments, the maximum number of nematode eggs, juveniles (J2s), females, and egg masses that were parasitized were quantified after a 72-h exposure to the fungus. The isolate Lm1 was designated as the best biocontrol agent against nematode eggs as well as J2s. It showed the highest colonization of eggs and significantly decreased egg hatching events. The results from two additional isolates, Lm2 and Lm3, were also significant (P = 0.05) but less pronounced than those observed with Lm1. L. muscarium treatments had significant (P = 0.05) positive effects on plant shoot and root growth compared with the growth of control plants. These results suggest the effectiveness of the fungus may be due to either the infection of eggs and J2s, or the production of secondary metabolites that induced plant defense mechanisms and lead to systemic resistance. Our study demonstrates that L. muscarium could be used as a potential biocontrol agent against root knot nematodes.

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