Host status of commonly grown cultivars of chillies(Capsicum frutescens)and sweet pepper(C. annuum)to the root‐knot nematode(Meloidogyne incognita)in northern Nigeria

The root-knot nematode Meloidogyne incognita (Kofoid & White) Chitwood is one of the most harmful species within the genus Meloidogyne. It has been detected regularly in greenhouses throughout Europe, while in the field it is restricted to the southern parts of Europe (4). M. incognita is able to parasitize more than 700 plant species and varieties, including the majority of our economically important crops (1). It has been recorded in most parts of the world, including former Yugoslavia; however, there is no data about its presence in Slovenia. In late summer of 2002, large galls were observed on roots of pepper, Capsicum annuum L., grown in a greenhouse located in Portorož near the Adriatic Coast of Slovenia. Different root-knot nematode stages, i.e., males, females, and second-stage juveniles, were isolated and morphologically identified as M. incognita (2). Additional isozyme gel electrophoresis confirmed this (3). To our knowledge, this is the first report of M. incognita from Slovenia. In addition, M. hapla Chitwood was found for the first time in a field in Slovenia. Previously, it had been detected on different host plants, all restricted to greenhouses. In October 2002, M. hapla was isolated and identified from relatively small galls of sweet pepper, C. annuum L., grown in a field near Ljubljana, located in central Slovenia. Additional resampling of the soil comfirmed the presence of M. hapla in this field. References: (1) J. D. Eisenback. Root-Knot Nematode Taxonomic Database. CD-ROM, CABI, Wallingford, UK, 1998. (2) J. D. Eisenback and H. Hirschmann Triantaphyllou. Root-knot nematodes: Meloidogyne species and races. Pages 191–274 in: Manual of Agricultural Nematology. W. R. Nickle, ed. Marcel Dekkers, Inc., New York, 1991. (3) P. R. Esbenshade and A. C. Triantaphyllou. J. Nematol. 17:6, 1985. (4) G. Karssen. Revision of the European root-knot nematodes III on mono- and dicotyledons. Pages 119–121 in: The Plant-Parasitic Nematode Genus Meloidogyne Göldi, 1892 (Tylenchida) in Europe. Koninklijke Brill NV, Leiden, the Netherlands, 2002.

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Life cycle duration of Meloidogyne incognita and host status of Brassicaceae and Capparaceae selected for glucosinate content

Nematology ◽

10.1163/1568541054879494 ◽

2005 ◽

Vol 7 (2) ◽

pp. 203-212 ◽

Cited By ~ 21

Author(s):

Elisabetta Dallavalle ◽

Luca Lazzeri ◽

Giovanna Curto

Keyword(s):

Life Cycle ◽

Meloidogyne Incognita ◽

Cropping System ◽

Cycle Duration ◽

Root Knot Nematode ◽

Tomato Cultivar ◽

Host Status ◽

Rapistrum Rugosum ◽

Susceptible Tomato ◽

Life Cycle Duration

AbstractDifferent plant species in the families Brassicaceae and Capparaceae were evaluated for their potential use in management of the root-knot nematode, Meloidogyne incognita. Preliminary tests on host suitability were carried out for toxic effects on the nematode in small field plots of soil naturally infested with M. incognita. Afterwards, the best accessions and a susceptible tomato cultivar (UC82) were tested in pots to collect more complete observations of the nematode life cycle on the selected plant roots. Plants were cultivated in the glasshouse for 14–15 weeks and evaluated every 2 weeks. Root gall rating, population reproduction factor and life cycle duration showed wide differences amongst the different accessions and indicated two distinct approaches for control of M. incognita: catch crops or green manure. At 14–15 weeks after sowing, Rapistrum rugosum sel. ISCI 15, Eruca sativa cv. Nemat, Barbarea verna sel. ISCI 50 and Raphanus sativus cv. Boss were considered 'poor to nonhost' species; Brassica juncea sel. ISCI 99 was classified as 'maintenance host'; Lepidium campestre sel. ISCI 103 and Erucastrum gallicum were 'good hosts'. At 10 weeks after sowing, B. juncea sel. ISCI 20 was classified as a good host, so it could be grown for fewer than 8–10 weeks in a cropping system. The presence of galls and the identification of juveniles, females and egg masses, confirmed that second-stage juveniles had penetrated into the root of the tested accessions and completed their life cycle. However, in R. rugosum sel. ISCI 15, M. incognita did not complete its life cycle, even after 15 weeks.

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Resistance mechanisms ofPrunusrootstocks to root-knot nematode,Meloidogyne incognita

Fruits ◽

10.1051/fruits/2009024 ◽

2009 ◽

Vol 64 (5) ◽

pp. 295-303 ◽

Cited By ~ 1

Author(s):

Hang Ye ◽

Wen-jun Wang ◽

Guo-jie Liu ◽

Li-xin Zhu ◽

Ke-gong Jia

Keyword(s):

Meloidogyne Incognita ◽

Resistance Mechanisms ◽

Root Knot Nematode

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dl-β-Amino butyric acid induced resistance in tomato against root-knot nematode Meloidogyne incognita under salt stress condition

Indian Phytopathology ◽

10.1007/s42360-021-00320-8 ◽

2021 ◽

Author(s):

Mohd Asif ◽

Faryad Khan ◽

Taruba Ansari ◽

Faheem Ahmad ◽

Moh Tariq ◽

...

Keyword(s):

Salt Stress ◽

Induced Resistance ◽

Butyric Acid ◽

Meloidogyne Incognita ◽

Stress Condition ◽

Root Knot Nematode ◽

Salt Stress Condition ◽

Amino Butyric Acid

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Genetic Diversity, Virulence, and Meloidogyne incognita Interactions of Fusarium oxysporum Isolates Causing Cotton Wilt in Georgia

Plant Disease ◽

10.1094/pdis-09-16-1382-re ◽

2017 ◽

Vol 101 (6) ◽

pp. 948-956 ◽

Cited By ~ 9

Author(s):

Alois A. Bell ◽

Robert C. Kemerait ◽

Carlos S. Ortiz ◽

Sandria Prom ◽

Jose Quintana ◽

...

Keyword(s):

Genetic Diversity ◽

Fusarium Oxysporum ◽

Meloidogyne Incognita ◽

Root Knot Nematode ◽

Soil Infestation ◽

Causal Pathogen ◽

Complementation Groups ◽

Shoot Weight ◽

Cotton Wilt ◽

Significant Disease

Locally severe outbreaks of Fusarium wilt of cotton (Gossypium spp.) in South Georgia raised concerns about the genotypes of the causal pathogen, Fusarium oxysporum f. sp. vasinfectum. Vegetative complementation tests and DNA sequence analysis were used to determine genetic diversity among 492 F. oxysporum f. sp. vasinfectum isolates obtained from 107 wilted plants collected from seven fields in five counties. Eight vegetative complementation groups (VCG) were found, with VCG 01117B and VCG 01121 occurring in 66% of the infected plants. The newly recognized VCG 01121 was the major VCG in Berrien County, the center of the outbreaks. All eight VCG resulted in significant increases in the percentages of wilted leaves (27 to 53%) and significant reductions in leaf weight (40 to 67%) and shoot weight (33 to 60%) after being stem punctured into Gossypium hirsutum ‘Rowden’. They caused little or no significant reductions in shoot weight and height or increases in foliar symptoms and vascular browning in a soil-infestation assay. Soil infestation with Meloidogyne incognita race 3 (root-knot nematode) alone also failed to cause significant disease. When coinoculated with M. incognita race 3, all VCG caused moderate to severe wilt. Therefore, the VCG identified in this study belong to the vascular-competent pathotype, and should pose similar threats to cotton cultivars in the presence of the root-knot nematode. Use of nematode-resistant cultivars, therefore, is probably the best approach to control the disease in Georgia.

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The role of Caenorhabditis elegans sex-determination homologs, Mi-sdc-1 and Mi-tra-1 in Meloidogyne incognita

European Journal of Plant Pathology ◽

10.1007/s10658-021-02335-3 ◽

2021 ◽

Author(s):

Anil Baniya ◽

Soumi Joseph ◽

Larry Duncan ◽

William Crow ◽

Tesfamariam Mengistu

Keyword(s):

Caenorhabditis Elegans ◽

Sex Determination ◽

Meloidogyne Incognita ◽

Egg Production ◽

Target Genes ◽

Parasitic Nematode ◽

Plant Parasitic Nematode ◽

Root Knot Nematode ◽

Model Free ◽

Plant Parasitic

AbstractSex determination is a key developmental event in all organisms. The pathway that regulates sexual fate has been well characterized at the molecular level in the model free-living nematode Caenorhabditis elegans. This study aims to gain a preliminary understanding of sex-determining pathways in a plant-parasitic nematode Meloidogyne incognita, and the extent to which the roles of the sex determination genes are conserved in a hermaphrodite species, C. elegans, and plant-parasitic nematode species, M. incognita. In this study, we targeted two sex-determining orthologues, sdc-1 and tra-1 from M. incognita using RNA interference (RNAi). RNAi was performed by soaking second-stage juveniles of M. incognita in a solution containing dsRNA of either Mi-tra-1or Mi-sdc-1 or both. To determine the effect of RNAi of the target genes, the juveniles treated with the dsRNA were inoculated onto a susceptible cultivar of cowpea grown in a nutrient pouch at 28 °C for 5 weeks. The development of the nematodes was analyzed at different time points during the growth period and compared to untreated controls. Our results showed that neither Mi-sdc-1 nor Mi-tra-1 have a significant role in regulating sexual fate in M. incognita. However, the silencing of Mi-sdc-1 significantly delayed maturity to adult females but did not affect egg production in mature females. In contrast, the downregulation of Mi-tra-1 transcript resulted in a significant reduction in egg production in both single and combinatorial RNAi-treated nematodes. Our results indicate that M. incognita may have adopted a divergent function for Mi-sdc-1 and Mi-tra-1distinct from Caenorhabditis spp. However, Mi-tra-1 might have an essential role in female fecundity in M. incognita and is a promising dsRNA target for root-knot nematode (RKN) management using host-delivered RNAi.

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