Susceptibility of Eight Herbs to Common Root-Knot Nematodes

Abstract Eight herb species were inoculated with two common species of root-knot nematode and grown for 2 months in a greenhouse. Root systems were examined for galls and egg mass production. All herb species were susceptible but developed fewer galls and had lower gall indices than Rutgers tomato. Burnet, chives, valerian and winter savory had few galls or low gall indices. Eggs were produced on all. Chamomile had a high gall index. Chicory, parsley, and sorrel had intermediate indices. Herbs were equally susceptible to the southern (Meloidogyne incognita) and peanut root-knot nematodes (M. arenaria), particularly at the highest inoculum densities. Mean dry weights of inoculated herbs were not always significantly less than the non-inoculated plants, suggesting that some herbs may be tolerant to root-knot nematodes.

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Survey and Identification of Root-Knot Nematodes Associated with Brinjal Crops in Fatehabad, Agra

Current Agriculture Research Journal ◽

10.12944/carj.4.1.13 ◽

2016 ◽

Vol 4 (1) ◽

pp. 114-119

Author(s):

Bindhya Yadav ◽

Sanoj Kumar

Keyword(s):

Meloidogyne Javanica ◽

Mixed Population ◽

Egg Mass ◽

Root Knot Nematode ◽

Index Point ◽

Root Knot Nematodes ◽

Heavy Infection ◽

Disease Occurrence ◽

Gall Index ◽

Almost All

A survey was conducted over a period of one and half year to estimate the occurrence of root-knot nematode disease on brinjal crops in five selected localities in and around Fatehabad, Agra. Our survey indicates that brinjal crops grown in the selected localities were heavily infested with root-knot nematodes. Highest frequency of disease occurrence in which almost all the roots have knot-like appearance (>85%) was reported from Firozabad Road area. Other localities were also having the significant infestations and these were reported as 80%, 78%, 65%,62% respectively. To access the damage caused by root-knot nematodes in brinjal crop, Meloidogyne gall index and its egg-mass index were calculated and these were found in the range of 2-5. An increased gall index and egg-mass index point to heavy infection on selected crops. Sampled crop showed the significant presence of Meloidogyne javanica. However, there were other species of root-knot nematode as mixed population was also reported. Other species of the root-knot nematodes which were reported in this survey was M. incognita. This survey indicates that the M. javanica is a frequently occurring population in brinjal field infested with root-knot disease.

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Weed Hosts of Root-Knot Nematodes and Their Distribution in Fiji

Weed Technology ◽

10.1614/wt-d-09-00071.1 ◽

2010 ◽

Vol 24 (4) ◽

pp. 607-612 ◽

Cited By ~ 6

Author(s):

Sunil K. Singh ◽

Uma R. Khurma ◽

Peter J. Lockhart

Keyword(s):

Soil Samples ◽

Egg Mass ◽

Weed Species ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Pests And Diseases ◽

Weed Hosts ◽

Host Status ◽

Gall Index ◽

Reservoir Hosts

Weeds can act as reservoir hosts of a range of pests and diseases. Information and knowledge on the host status of weeds to common pests and diseases can be used to develop integrated weed and pest management strategies. As part of a survey on the distribution and diversity of root-knot nematodes on crops in Fiji, the root-knot nematode host status of weeds was also studied. Weeds growing in root-knot nematode infested farms (n= 189) and bioassay pot soil samples (n= 277) were identified, and their host status was determined on the basis of a root gall and egg-mass index scale from 0 to 5. A total of 45 weed species were recorded as potential weed hosts of root-knot nematodes with a gall index from 1 to 5. Using the weed and tomato bioassay method, a total of 11 nonhost weed species were recorded with a gall index of 0, relative to infected tomato growing in pot soil samples. Common weeds infected by root-knot nematodes on farms and in bioassay pot soil included slender amaranth, old world diamond-flower, tropic ageratum, sicklepod, mimbra, balsamapple, purple bushbean, little ironweed, ivy gourd, and cutleaf groundcherry. The presence of egg masses on the weed hosts indicated their ability to sustain root-knot nematode populations and, thus, their potential to act as reservoir hosts.

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Biocontrol agents in the management of Meloidogyne incognita in tomato

Ciência Rural ◽

10.1590/0103-8478cr20161053 ◽

2017 ◽

Vol 47 (10) ◽

Cited By ~ 8

Author(s):

Juliana de Oliveira Silva ◽

Marcus Vinícius Santana ◽

Leonardo Levorato Freire ◽

Bruno da Silva Ferreira ◽

Mara Rúbia da Rocha

Keyword(s):

Population Density ◽

Meloidogyne Incognita ◽

Biocontrol Agents ◽

Egg Mass ◽

Root Knot Nematode ◽

Tomato Crop ◽

Tomato Plants ◽

Biological Products ◽

Gall Index ◽

Different Doses

ABSTRACT: Recognized as prominent among the principal pests of tomato crop, the root-knot nematode (Meloidogyne incognita) has generated much study with regards to control methods. This study aimed to assess the efficiency of biological products in decreasing the M. incognita population in tomato. Four experiments were conducted under greenhouse conditions. Two of these experiments had the purpose to determine the efficiency of NemOut™ (Bacillus subtilis + B. licheniformis + Trichoderma longibrachiatum), and the other two to assess the efficiency of other different biological products in M. incognita management. Tomato plants of the cultivar Santa Cruz Kada Giant were inoculated using 2000 eggs and J2 of M. incognita. In the first two experiments doses corresponding to 0, 4, 6, 8 and 10kg ha-1 of NemOut™ were applied after inoculation. In the second study, the treatments consisted of the use of biological products containing different other biocontrol agents. Assessments were made at 45 and 65 days after inoculation (DAI) to evaluate plant height, fresh shoot and fresh root weigh, gall index and egg mass index, population density and reproduction factor (RF). The NemOut™ doses reduced the M. incognita population density and RF at 45 DAI. The agent Pochonia chlamydosporia showed greater efficiency in controlling M. incognita on tomato. Biological products and the different doses of NemOut™ had no influence on the tomato plant development.

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Responses of Capsicum annuum Varieties toward Root Knot Nematode Meloidogyne incognita Infection

Jurnal Perlindungan Tanaman Indonesia ◽

10.22146/jpti.23978 ◽

2020 ◽

Vol 24 (2) ◽

pp. 133

Author(s):

Resty Islamiati Putri ◽

Siwi Indarti ◽

Ani Widiastuti

Keyword(s):

Capsicum Annuum ◽

Meloidogyne Incognita ◽

Crop Protection ◽

Root Systems ◽

Chili Pepper ◽

Egg Mass ◽

Root Weight ◽

Root Knot Nematode ◽

Plant Pest ◽

Root Tissues

Chili pepper (Capsicum annuum) is one of the major vegetable commodities in Indonesia. One of the challenges in chili pepper cultivation is the infection of Meloidogyne incognita which causes gall formation in root systems. The purposes of this research were to determine 1. the response of four varieties of chili pepper against M. incognita infections; 2. damaged intensity caused by this pest in the root system, and; 3. development of M. incognita populations in root systems (rhizosphere). This research was conducted in Plant Pest Science Laboratory and Greenhouse of the Department of Crop Protection, Faculty of Agriculture, University of Gadjah Mada. This research included cultivation of three chili pepper varieties (Cabai Merah Besar, Pilar F1; Cabai Merah Keriting, Kastilo F1; and Paprika, Red Star 2060), rearing of M. incognita, inoculation, and observation. Chili pepper respond to M. incognita infections were evaluated based on agronomic aspects of the plants, such as root histopathology observation, disease intensity, and nematode populations. Results showed that each variety of chili pepper expressed various responses to infections. All varieties had different root weight and length, but had similar sensitivity based on the appearance of root damage and egg mass scoring of M. incognita. Although nematode population could develop on roots, observation from root tissues showed lignification after infection of J2 M. incognita. Chili pepper var. Red Star 2060 was more susceptible against M. incognita than chili pepper var. Pilar F1 and chili pepper var. Kastilo F1.

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Pathogenicity and Volatile Nematicidal Metabolites from Duddingtonia flagrans against Meloidogyne incognita

Microorganisms ◽

10.3390/microorganisms9112268 ◽

2021 ◽

Vol 9 (11) ◽

pp. 2268

Author(s):

Xiaoyu Mei ◽

Xin Wang ◽

Guohong Li

Keyword(s):

Meloidogyne Incognita ◽

Plant Pathogens ◽

Plant Root ◽

Nematicidal Activity ◽

Mass Spectrometry Analysis ◽

Gas Chromatography Mass Spectrometry ◽

Egg Mass ◽

Duddingtonia Flagrans ◽

Egg Hatching ◽

Root Knot Nematodes

Plant parasitic nematodes, especially parasitic root-knot nematodes, are one of the most destructive plant pathogens worldwide. The control of plant root-knot nematodes is extremely challenging. Duddingtonia flagrans is a type of nematode-trapping fungi (NTF), which produces three-dimensional adhesive networks to trap nematodes. In this study, the pathogenicity and volatile organic compounds (VOCs) of the NTF D. flagrans against the plant root-knot nematode, Meloidogyne incognita, were investigated. The predatory process of D. flagrans trapping M. incognita was observed using scanning electron microscopy. Gas chromatography-mass spectrometry analysis of the VOCs from D. flagrans led to the identification of 52 metabolites, of which 11 main compounds were tested individually for their activity against M. incognita. Three compounds, cyclohexanamine, cyclohexanone, and cyclohexanol, were toxic to M. incognita. Furthermore, these three VOCs inhibited egg hatching of M. incognita. Cyclohexanamine showed the highest nematicidal activity, which can cause 97.93% mortality of M. incognita at 8.71 µM within 12 h. The number of hatched juveniles per egg mass after 3 days was just 8.44 when treated with 26.14 µM cyclohexanamine. This study is the first to demonstrate the nematicidal activity of VOCs produced by D. flagrans against M. incognita, which indicates that D. flagrans has the potential to biocontrol plant root-knot nematodes.

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Genome expression dynamics reveals parasitism regulatory landscape of the root-knot nematode Meloidogyne incognita and a promoter motif associated with effector genes

10.1101/2021.04.02.438169 ◽

2021 ◽

Author(s):

Martine Da Rocha ◽

Caroline Bournaud ◽

Julie Dazeniere ◽

Peter Thorpe ◽

Clement Pellegrin ◽

...

Keyword(s):

Gene Expression ◽

Meloidogyne Incognita ◽

Life Stage ◽

Regulation Of Gene Expression ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Control Of Gene Expression ◽

Precise Control ◽

Effector Genes ◽

Spatio Temporal

Root-knot nematodes are the major contributor to the crop losses caused by nematodes. Root-knot nematodes secrete effectors into the plant, derived from two sets of pharyngeal gland cells, to manipulate host physiology and immunity. Successful completion of the life cycle, involving successive molts from egg to adult, covers morphologically and functionally distinct stages and will require precise control of gene expression, including effectors. The details of how root-knot nematodes regulate transcription remain sparse. Here, we report a life stage-specific transcriptome of Meloidogyne incognita. Combined with an available annotated genome, we explore the spatio-temporal regulation of gene expression. We reveal gene expression clusters and predicted functions that accompany the major developmental transitions. Focusing on effectors, we identify a putative cis-regulatory motif associated with expression in the dorsal glands: providing an insight into effector regulation. We combine the presence of this motif with several other criteria to predict a novel set of putative dorsal gland effectors. Finally, we show this motif, and thereby its utility, is broadly conserved across the Meloidogyne genus and termed it Mel-DOG. Taken together, we provide the first genome-wide analysis of spatio-temporal gene expression in a root-knot nematode, and identify a new set of candidate effector genes that will guide future functional analyses.

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Reproduction of Meloidogyne enterolobii in lettuce cultivars of the American group

Horticultura Brasileira ◽

10.1590/s0102-053620150000200002 ◽

2015 ◽

Vol 33 (2) ◽

pp. 147-150

Author(s):

Érika CSS Correia ◽

Norberto Silva ◽

Marylia GS Costa ◽

Silvia RS Wilcken

Keyword(s):

Reproductive Potential ◽

Egg Mass ◽

Root Knot Nematodes ◽

Second Stage ◽

American Group ◽

Meloidogyne Enterolobii ◽

Meloidogyne Spp ◽

Gall Index ◽

Summer Time ◽

Reproduction Factor

Lettuce is the main vegetable cultivated in Brazil, in volume and in marketed value. There are ranges of diseases which may affect lettuce crops, including those caused by root-knot nematodes (Meloidogyne spp.). We evaluated the reproductive potential of Meloidogyne enterolobii in 22 lettuce cultivars. The plants were inoculated with 5,000 eggs and eventuals second stage juveniles of nematode per pot, two days after the transplanting. 'Rutgers' tomato was used as standard for inoculum viability of M. enterolobii. We evaluated, 60 days after inoculation, the gall index, egg mass index and reproduction factor (RF). The 'Ithaca', 'Raider Plus', 'RS-1397', 'L-104', 'Challenge', 'IP-11', 'Classic', 'Salinas 88', 'Vanguard 75', 'Calona' and 'Desert Queen' were resistant to M. enterolobii with RF varying from 0.22 to 0.9, and the cultivars Lady Winterset, Robinson, Sonoma, Raider, Lucy Brown, Bnondaga, Summer Time, Taina, Sundevil and L-109 were susceptible to this nematode, with RF ranging from 1.06 to 5.73.

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Application of Biogas Digestate with Rice Straw Mitigates Nitrate Leaching Potential and Suppresses Root-Knot Nematode (Meloidogyne incognita)

Agronomy ◽

10.3390/agronomy9050227 ◽

2019 ◽

Vol 9 (5) ◽

pp. 227 ◽

Cited By ~ 4

Author(s):

Yuexi Wang ◽

Seiya Chikamatsu ◽

Tuya Gegen ◽

Kozue Sawada ◽

Koki Toyota ◽

...

Keyword(s):

Rice Straw ◽

Nitrate Leaching ◽

Meloidogyne Incognita ◽

Application Rate ◽

Pig Manure ◽

Test Plant ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Leaching Potential ◽

Biogas Digestate

This study investigated the effects of biogas digestate application to soil with rice straw on nitrate leaching potential and nematicidal activity toward root-knot nematodes Meloidogyne incognita. The following seven treatments were set up: (i) control (CONT); (ii) chemical fertilizer (CF); (iii) wet biogas digestate derived from pig manure (WBD); (iv) and (v) dry biogas digestate derived from a mixture of pig manure and rice straw at an initial C/N ratio of 20 and 30 (DBD20 and DBD30); (vi) and (vii) DBD20 mixed with rice straw to adjust the C/N ratio to 16 (Mix1) and 30 (Mix2), respectively. The application rate of CF and digestates was adjusted to 200 mg N kg−1 soil based on the inorganic ammonium nitrogen contents. Nitrate contents readily increased in all the treatments with incubation, except for Mix2, and those at day 90 were decreased with increasing initial labile C contents. Garden balsam was grown as a test plant for root-knot nematodes using the soils at day 90 and the results showed that the gall index was significantly lower in Mix2 and Mix1 than in CF. These results suggest that dry digestate mixed with rice straw might have potential for lower nitrate leaching and nematicidal properties.

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Yellow Nutsedge Response to Southern Root-Knot Nematodes, Chile Peppers, and Metolachlor

Weed Science ◽

10.1017/s0043174500076906 ◽

1994 ◽

Vol 42 (4) ◽

pp. 534-540 ◽

Cited By ~ 8

Author(s):

Jill Schroeder ◽

Michael J. Kenney ◽

Stephen H. Thomas ◽

Leigh Murray

Keyword(s):

Host Plant ◽

Plant Root ◽

Root Systems ◽

Root Mass ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Yellow Nutsedge ◽

Greenhouse Experiments ◽

Shoot Number ◽

Chile Peppers

Greenhouse experiments showed that yellow nutsedge shoot number and shoot and root dry weights were reduced by root-knot nematodes and chile peppers. Root-knot nematodes increased and chile peppers decreased the number of yellow nutsedge tubers. Yellow nutsedge tuber germination was reduced by chile peppers but not by root-knot nematodes. Yellow nutsedge established from root-knot nematode-infected tubers produced more tubers than noninfected tubers. Root-knot nematode populations became established on yellow nutsedge root systems when plants were established from tubers previously cultured with root-knot nematodes. Metolachlor stunted chile peppers, eliminated yellow nutsedge, and influenced root-knot nematode populations through reduction of host plant root mass. However, when root-knot nematodes were present, yellow nutsedge tuber germination was not affected by metolachlor. This research indicates that the pests do not exist independently and that their management may be interrelated.

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Comparison of host recognition, invasion, development and reproduction of Meloidogyne graminicola and M. incognita on rice and tomato

Nematology ◽

10.1163/138855410x528262 ◽

2011 ◽

Vol 13 (5) ◽

pp. 509-520 ◽

Cited By ~ 19

Author(s):

Tushar K. Dutta ◽

Stephen J. Powers ◽

Brian R. Kerry ◽

Hari S. Gaur ◽

Rosane H.C. Curtis

Keyword(s):

Meloidogyne Incognita ◽

Host Recognition ◽

Cortical Region ◽

Root Knot Nematode ◽

Root Tips ◽

Root Knot Nematodes ◽

Tomato Plants ◽

Meloidogyne Graminicola ◽

Second Stage ◽

Tomato Roots

AbstractThe rice root-knot nematode Meloidogyne graminicola normally infects rice, wheat and several other graminaceous plants. Meloidogyne incognita is a serious pest of dicotyledonous crops, although it can infect and reproduce on some cereals. This paper demonstrates and compares host recognition, development and reproduction of these two species of root-knot nematodes on rice and tomato plants. Attraction bioassays in pluronic gel clearly showed that M. incognita preferred tomato roots to rice or mustard roots, whilst M. graminicola was more attracted towards rice compared with tomato or mustard roots. Based on the attraction data from this study, it can be hypothesised that either: i) the blend of attractants and repellents are different in good and poor hosts; or ii) relatively long-range attractants, together with shorter-range repellents, might affect nematode movement patterns. Some host specific attractants might also be involved. Meloidogyne incognita was able to invade and develop to adult female but did not produce eggs in rice roots. By contrast, M. graminicola developed and reproduced faster on both rice and tomato plants compared with M. incognita. Nevertheless, second-stage juveniles of both these root-knot nematodes showed a similar pattern of distribution inside the roots, preferring to accumulate at the root tips of rice or in the vascular cylinder and cortical region of tomato.

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