Multiyear Evaluation of the Durability of the Resistance Conferred by Ma and RMia Genes to Meloidogyne incognita in Prunus Under Controlled Conditions

Root-knot nematodes (RKNs) (Meloidogyne spp.) are highly polyphagous pests that parasitize Prunus crops in Mediterranean climates. Breeding for RKN-resistant Prunus cultivars, as an alternative to the now-banned use of nematicides, is a real challenge, because the perennial nature of these trees increases the risk of resistance breakdown. The Ma plum resistance (R) gene, with a complete spectrum, and the RMia peach R gene, with a more restricted spectrum, both provide total control of Meloidogyne incognita, the model parthenogenetic species of the genus and the most important RKN in terms of economic losses. We investigated the durability of the resistance to this nematode conferred by these genes, comparing the results obtained with those for the tomato Mi-1 reference gene. In multiyear experiments, we applied a high and continuous nematode inoculum pressure by cultivating nematode-infested susceptible tomato plants with either Prunus accessions carrying Ma or RMia R genes, or with resistant tomato plants carrying the Mi-1 gene. Suitable conditions for Prunus development were achieved by carrying out the studies in a glasshouse, in controlled conditions allowing a short winter leaf fall and dormancy. We first assessed the plum accession ‘P.2175’, which is heterozygous for the Ma gene, in two successive 2-year evaluations, for resistance to two M. incognita isolates. Whatever the isolate used, no nematodes reproducing on P.2175 were detected, whereas galls and nematodes reproducing on tomato plants carrying Mi-1 were observed. In a second experiment with the most aggressive isolate, interspecific full-sib material (P.2175 × [‘Garfi’ almond × ‘Nemared’ peach]), carrying either Ma or RMia (from Nemared) or both (in the heterozygous state) or neither of these genes, was evaluated for 4 years. No virulent nematodes developed on Prunus spp. carrying R genes, whereas galling and virulent individuals were observed on Mi-1-resistant tomato plants. Thus, the resistance to M. incognita conferred by Ma in Prunus material in both a pure-plum and an interspecific genetic background, or by RMia in an interspecific background, appears to be durable, highlighting the value of these two genes for the creation of Prunus rootstock material.

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INFLUENCE OF FOLIAR TREATMENTS OF TOMATO PLANTS WITH MICROELEMENTS ON ROOT-KNOT NEMATODE INFESTATION

10.31016/978-5-6046256-1-3.2021.22.520-525 ◽

2021 ◽

pp. 520-525

Author(s):

Udalova ◽

Zinovieva

Keyword(s):

Photosynthetic Pigments ◽

Meloidogyne Incognita ◽

Growth And Development ◽

Metabolic Effect ◽

Plant Tissues ◽

Pathological State ◽

Qualitative Composition ◽

Root Knot Nematode ◽

Tomato Plants ◽

Susceptible Tomato

Selenium (Se), silicon (Si) and nickel (Ni) are essential microelements in plants. Their deficiency can have a significant impact on the growth and development of plants, and on nematode infestation. The study of the possibility of regulating the interaction of plants with root-knot nematode by means of exogenous foliar treatments with solutions of nanosized Se, Si and Ni has been conducted. Susceptible tomato plants were treated in the seed phase and the growing plants were sprayed with aqueous solutions of nanosized microelements (Se – 0.6; Ni – 0.1; Si – 2 mg/l). The influence of treatments on the infestation of tomatoes by the root-knot nematode Meloidogyne incognita, as well as on the development of plants and the quantitative and qualitative composition of photosynthetic pigments, as the most sensitive indicator of the pathological state of plants, was studied. A decrease in the infestation of tomatoes with a nematode in the Se<Si<Ni series is shown. The treated plants were dominated by larvae. An increase in the entire pool of photosynthetic pigments or individual pigments was observed when treated with nanosized microelements. The greatest effect on the infestation of the root system, the development of nematodes and the content of photosynthetic pigments was obtained when plants were treated with nanosized nickel. It is obvious that these elements have an individual metabolic effect on plant tissues, but it is obvious that they have a beneficial effect on tomato plants, which allows us to consider them as inductors that increase resistance to root-knot nematode.

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Use of organic amendments in the management of root-knot nematode in lettuce

Horticultura Brasileira ◽

10.1590/s0102-053620150000400013 ◽

2015 ◽

Vol 33 (4) ◽

pp. 488-492 ◽

Cited By ~ 1

Author(s):

Claudia R Dias-Arieira ◽

Danielle Mattei ◽

Heriksen H Puerari ◽

Regina CF Ribeiro

Keyword(s):

Whey Protein ◽

Meloidogyne Incognita ◽

Organic Amendments ◽

Wood Chip ◽

Control Treatment ◽

Initial Population ◽

Root Knot Nematode ◽

Tomato Plants ◽

Crambe Meal ◽

Meloidogyne Spp

ABSTRACT: Root-knot nematodes, Meloidogyne spp., are among the most important parasites of the lettuce crop. Managing these organisms is difficult due to limitations in genetic (use of resistant cultivars) and chemical control. Thus, new practices should be sought to reduce their reproduction. The present study aimed to evaluate the application of organic amendments in the control of Meloidogyne incognita in lettuce. At first, tomato plants were inoculated to establish an initial population in the soil. After 60 days, the aerial part was discarded, and the lettuce seedlings were transplanted into pots. Two days after transplanting, the treatments bokashi, crambe cake, whey protein, cottonseed composted and shredded wood chip composted were applied at 20 g or 20 mL per pot. Water was applied as control treatment. After 70 days, bokashi and crambe meal reduced the number of eggs/g of root and promoted plant growth. Results obtained with whey protein, cottonseed meal and composted shredded wood chip did not differ from those obtained with the control treatment. Bokashi and crambe cake are effective in the M. incognita control under controlled conditions.

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Potential of non-fumigant nematicides at different formulations against southern root-knot nematode (Meloidogyne incognita) on tomato plants

International Journal of Phytopathology ◽

10.33687/phytopath.008.01.2899 ◽

2019 ◽

Vol 8 (1) ◽

pp. 23-28

Author(s):

Mohamed S. Khalil ◽

Abdulqawi A. A. Alqadasi

Keyword(s):

Meloidogyne Incognita ◽

Dry Weight ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Tomato Plants ◽

Shoot Dry Weight ◽

Soil Population ◽

Meloidogyne Spp ◽

Southern Root Knot Nematode

Currently, plant parasitic nematodes (PPN) especially root knot nematodes, Meloidogyne spp. have been found involved in the global losses of tomato crops. The most employed tactic for managing PPN in Africa is non-fumigant nematicides. Recently, in Egypt abamectin was recorded as a new tool to control PPN. Thus, two pot experiments were conducted to evaluate the potential of abamectin and certain non-fumigant nematicides namely; oxamyl and ethoprophos at two different formulations (granular and liquid) against southern root knot nematode (Meloidogyne incognita) on tomato plants under greenhouse conditions. Results revealed the granular formulations of ethoprophos and oxamyl, in addition to abamectin, showed the same significance (P≤0.05) in suppressing tomato soil population and root galls of M. incognita, during both experiments. However, liquid formulations of ethoprophos and oxamyl gave relatively less decreasing in soil population and root galls. On the other hand, all applied treatments improved plant growth criteria ranging from 36.92 to 126.44% in shoot dry weight and from 31.25 to 137.50% in root dry weight for both experiments.

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Polysulfides Applied as Formulated Garlic Extract to Protect Tomato Plants against the Root-Knot Nematode Meloidogyne incognita

Plants ◽

10.3390/plants10020394 ◽

2021 ◽

Vol 10 (2) ◽

pp. 394

Author(s):

Reinhard Eder ◽

Erika Consoli ◽

Jürgen Krauss ◽

Paul Dahlin

Keyword(s):

Meloidogyne Incognita ◽

Economic Losses ◽

Severe Damage ◽

Root Knot Nematode ◽

Tomato Plants ◽

Greenhouse Crops ◽

Tomato Roots ◽

Active Substances ◽

Roots In Vitro

The devastating root-knot nematode Meloidogyne incognita can cause severe damage to field and greenhouse crops. Due to high economic losses, alternative products are essential to replace banned or strictly regulated nematicides that affect human health and/or the environment. Garlic based products have been previously investigated as environmentally friendly nematicides and their active substances, diallyl polysulfides exist as formulated nematicides on the market. We tested the garlic-based nematicide NEMguard® DE as protective of tomato roots. In vitro evaluation of the lethal concentration (LC) showed strong nematicidal activity with LC50 of 0.8 mg/mL after 96 h and LC90 of 1.5 mg/mL. NEMguard® DE showed protective effect against M. incognita as a single application in small pots and a second application further reduced root galling, significantly. Large greenhouse trials were carried out in two consecutive years to test single and monthly applications of NEMguard® DE. In both years, no controlling effect could be observed on M.incognita. We assume that the silt content of the loamy sandy soil used had an effect on the polysulfides, inhibiting their nematicidal effect. We conclude that further experiments are necessary to investigate the nematicidal potential of NEMguard® DE under different soil compositions or as a different formulation.

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Bacterial volatile-mediated suppression of root-knot nematode (Meloidogyne incognita)

Plant Disease ◽

10.1094/pdis-06-21-1139-re ◽

2021 ◽

Author(s):

Ting Yang ◽

Yi Xin ◽

Tongyao Liu ◽

Zhengfeng Li ◽

Xingzhong Liu ◽

...

Keyword(s):

Meloidogyne Incognita ◽

Dimethyl Disulfide ◽

Gas Chromatography Mass Spectrometry ◽

Economic Losses ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Juvenile Mortality ◽

Rhizosphere Microorganisms ◽

Important Approach ◽

Meloidogyne Spp

Root-knot nematodes (Meloidogyne spp.) are obligate plant parasites that cause severe economic losses to agricultural crops worldwide. Due to serious health and environmental concerns related to the use of chemical nematicides, the development of efficient alternatives is of great importance. Biological control through exploiting the potential of rhizosphere microorganisms is currently accepted as an important approach for pest management in sustainable agriculture. In our research, during screening of rhizosphere bacteria against the root-knot nematodes Meloidogyne incognita, Ochrobactrum pseudogrignonense strain NC1 from the rhizosphere of healthy tomatoes showed strong nematode inhibition. A volatile nematicidal assay showed that the cell-free fermentation filtrate in the first-row wells of 12-well tissue culture plates caused M. incognita juvenile mortality in the second-row wells. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that dimethyl disulfide (DMDS) and benzaldehyde were the main volatile compounds produced by strain NC1. The nematicidal activity of these compounds indicated that the LC50 against the M. incognita juveniles in the second-row wells and the fourth-row wells were 23.4 μmol/mL and 30.7 μmol/mL for DMDS and 4.7 μmol/mL and 15.2 μmol/mL for benzaldehyde, respectively. A greenhouse trial using O. pseudogrignonense strain NC1 provided management efficiencies of root-knot nematodes of 88 to 100% compared with the untreated control. This study demonstrated that nematode-induced root-gall suppression mediated by the bacterial volatiles DMDS and benzaldehyde presents a new opportunity for root-knot nematode management.

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New Data Completing the Spectrum of the Ma, RMia, and RMja Genes for Resistance to Root-Knot Nematodes (Meloidogyne spp.) in Prunus

Phytopathology ◽

10.1094/phyto-05-18-0173-r ◽

2019 ◽

Vol 109 (4) ◽

pp. 615-622 ◽

Cited By ~ 2

Author(s):

Henri Duval ◽

Cyril Van Ghelder ◽

Ulysse Portier ◽

Carole Confolent ◽

Pablo Meza ◽

...

Keyword(s):

Molecular Mechanisms ◽

Resistance Management ◽

Stone Fruit ◽

R Genes ◽

Root Knot Nematodes ◽

Meloidogyne Spp ◽

Materials Used ◽

Number Of Individuals ◽

Prevalent Species ◽

Prunus Spp

Root-knot nematodes (RKN) (Meloidogyne spp.) are worldwide pests that affect a considerable number of plants, among which stone fruit (Prunus spp.) are severely attacked. Prevalent RKN species are Meloidogyne arenaria, M. incognita, and M. javanica in stone fruit but the emergent M. ethiopica and M. enterolobii are also reported to challenge perennial crops. In Prunus spp., the complete-spectrum resistance (R) gene Ma from plum and the more restricted-spectrum R genes RMia from peach and RMja from almond completely inhibit nematode multiplication and gall formation of the RKN species that they control. This study aimed to update the resistance spectra of these three major genes by evaluating their activity toward one isolate of the yet-untested RKN species mentioned above. To state whether a given gene controls a particular species, the principle of our experiment was to genotype with appropriate markers a number of individuals segregating for this gene and then to phenotype these individuals. A perfect matching of the genotype and the phenotype of individuals indicates that the gene of interest is active against and, thus, controls the corresponding isolate of this RKN species. Segregating materials used were an Ma F1 plum progeny, an RMia F2 peach progeny, and an RMja F2 almond progeny. In addition to previous data, our results establish a clear spectrum for each of the three genes toward isolates from both the three prevalent species and the two emerging species. Ultimately, our results reveal that (i) Ma controls all of them, (ii) RMja controls all species except M. incognita and M. floridensis, and (iii) RMia controls M. arenaria, M. incognita, and M. ethiopica but not M. javanica or M. enterolobii. Our data should have wide implications for RKN resistance management and breeding and for deciphering the molecular mechanisms of the spectrum of RKN R genes.

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Nematostatic effects of a leaf extract from Crotalaria virgulata subsp. grantiana on Meloidogyne incognita and its use to protect tomato roots

Nematology ◽

10.1163/156854104323072955 ◽

2004 ◽

Vol 6 (1) ◽

pp. 79-84 ◽

Cited By ~ 14

Author(s):

Philippe Jourand ◽

Sylvie Rapior ◽

Mireille Fargette ◽

Thierry Mateille

Keyword(s):

Aqueous Extract ◽

Meloidogyne Incognita ◽

Population Control ◽

Vegetable Crops ◽

Tomato Plants ◽

Sandy Substrate ◽

Synthetic Chemicals ◽

Tomato Roots ◽

Freeze Dried ◽

Susceptible Tomato

Abstract An aqueous extract from leaves of Crotalaria virgulata subsp. grantiana was assayed for its effects on second-stage juveniles of Meloidogyne incognita. The biological activity was nematostatic; nematodes were not killed but were completely paralysed in a 1 mg/ml (w/v) extract: the LD50 equivalent was estimated to be 0.5 mg/ml. The effect was reversible: juveniles previously paralysed by C. grantiana extract recovered complete mobility in water and were able to infest a susceptible tomato plant. Freeze-dried aqueous extract from C. grantiana leaves added to a sterile sandy substrate at 1 mg/ml protected susceptible tomato plants from M. incognita infestation. This suggests a promising use of C. grantiana as both a green manure and natural alternative to synthetic chemicals in nematode population control, especially in integrated pest management for vegetable crops in organic agriculture of tropical and temperate areas.

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Distribution of Meloidogyne species in carrot in Brazil

Ciência Rural ◽

10.1590/0103-8478cr20200552 ◽

2021 ◽

Vol 51 (5) ◽

Author(s):

Tiago Garcia da Cunha ◽

Liliane Evangelista Visôtto ◽

Letícia Mendes Pinheiro ◽

Pedro Ivo Vieira Good God ◽

Juliana Magrinelli Osório Rosa ◽

...

Keyword(s):

Meloidogyne Incognita ◽

Soil Samples ◽

Molecular Techniques ◽

Economic Losses ◽

Specific Pcr ◽

Meloidogyne Spp ◽

Mixed Populations ◽

Species Specific ◽

Meloidogyne Species ◽

Esterase Phenotypes

ABSTRACT: Root-knot nematodes (RKN - Meloidogyne spp.) are one of the most serious threats to carrot production worldwide. In Brazil, carrots are grown throughout the year, and economic losses due to RKN are reported. Since little is known on the distribution of RKN species in carrot fields in Brazil, we collected plant and soil samples from 35 fields across six states. Based on the morphology of perineal patterns, esterase phenotypes and species-specific PCR, three Meloidogyne species were identified: 60% of the fields were infested with Meloidogyne incognita, M. javanica was reported in 42.9% of the areas, whereas M. hapla was detected in 17.1% of carrot fields. Mixed populations were reported in 20% of the areas with a predominance of M. incognita + M. javanica. The combination of morphological, biochemical, and molecular techniques is a useful approach to identify RKN species.

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Isolation and Characterization Of Rice R Genes: Evidence for Distinct Evolutionary Paths in Rice and Maize

Genetics ◽

10.1093/genetics/142.3.1021 ◽

1996 ◽

Vol 142 (3) ◽

pp. 1021-1031 ◽

Cited By ~ 3

Author(s):

Jianping Hu ◽

Beth Anderson ◽

Susan R Wessler

Keyword(s):

Gene Family ◽

Gene Families ◽

Chromosome 1 ◽

R Gene ◽

R Genes ◽

Helix Loop Helix ◽

Isolation And Characterization ◽

Undetermined Function ◽

Evolutionary Paths

Abstract R and B genes and their homologues encode basic helix-loop-helix (bHLH) transcriptional activators that regulate the anthocyanin biosynthetic pathway in flowering plants. In maize, R/B genes comprise a very small gene family whose organization reflects the unique evolutionary history and genome architecture of maize. To know whether the organization of the R gene family could provide information about the origins of the distantly related grass rice, we characterized members of the R gene family from rice Oryza sativa. Despite being a true diploid, O. sativa has at least two R genes. An active homologue (Ra) with extensive homology with other R genes is located at a position on chromosome 4 previously shown to be in synteny with regions of maize chromosomes 2 and 10 that contain the B and R loci, respectively. A second rice R gene (Rb) of undetermined function was identified on chromosome 1 and found to be present only in rice species with AA genomes. All non-AA species have but one R gene that is Ra-like. These data suggest that the common ancestor shared by maize and rice had a single R gene and that the small R gene families of grasses have arisen recently and independently.

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Recent Findings Unravel Genes and Genetic Factors Underlying Leptosphaeria maculans Resistance in Brassica napus and Its Relatives

International Journal of Molecular Sciences ◽

10.3390/ijms22010313 ◽

2020 ◽

Vol 22 (1) ◽

pp. 313

Author(s):

Aldrin Y. Cantila ◽

Nur Shuhadah Mohd Saad ◽

Junrey C. Amas ◽

David Edwards ◽

Jacqueline Batley

Keyword(s):

Brassica Napus ◽

Genetic Factors ◽

Quantitative Resistance ◽

Genetic Resistance ◽

Leptosphaeria Maculans ◽

Gene Interaction ◽

R Gene ◽

R Genes ◽

Blackleg Resistance ◽

Avr Gene

Among the Brassica oilseeds, canola (Brassica napus) is the most economically significant globally. However, its production can be limited by blackleg disease, caused by the fungal pathogen Lepstosphaeria maculans. The deployment of resistance genes has been implemented as one of the key strategies to manage the disease. Genetic resistance against blackleg comes in two forms: qualitative resistance, controlled by a single, major resistance gene (R gene), and quantitative resistance (QR), controlled by numerous, small effect loci. R-gene-mediated blackleg resistance has been extensively studied, wherein several genomic regions harbouring R genes against L. maculans have been identified and three of these genes were cloned. These studies advance our understanding of the mechanism of R gene and pathogen avirulence (Avr) gene interaction. Notably, these studies revealed a more complex interaction than originally thought. Advances in genomics help unravel these complexities, providing insights into the genes and genetic factors towards improving blackleg resistance. Here, we aim to discuss the existing R-gene-mediated resistance, make a summary of candidate R genes against the disease, and emphasise the role of players involved in the pathogenicity and resistance. The comprehensive result will allow breeders to improve resistance to L. maculans, thereby increasing yield.

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