Root-knot Control Research Articles

Biocontrol of root knot nematodes by endophytic fungus isolated from garlic

Because of the endophytic fungi's ability to improve host plant fitness and boost their defense they have been used as to control root knot nematode (RKN) infection. RKNs induce root galls by altering growth pattern in the cell elongation zone, thereby obstructing nutrient transport to various parts of the plant. This project was designed to control RKN infestation in Solanum melongena by utilizing plant-friendly endophytic fungi. Garlic plants were used to isolate endophytic fungi which were then screened for their potential to inhibit RKN in S. melongena. Based on its namatocidal potential, the endophyte strain, named GR was selected and identified to be Aspergillus fumigatus with the help of the internal transcribed spacer (ITS) segment of the rRNA genes. The fungus had the ability to release indole acetic acid (IAA), salicylic acid (SA), phenols and flavonoids. The potential endophytes were assessed for the biocontrol of RKN in S. melongena seedlings grown in pots. The isolated strain conferred resistance to RKN penetration, leading to a substantial reduction in the frequency of root galls by 6.8-fold than the control. In comparison to control, endophyte-associated seedlings exhibited a 50 % increase in SA levels, indicating a SA-dependent defense against RKN. The activity of catalase and ascorbic acid was also boosted to suppress ROS generated in the RKN infested seedlings. The culture of the endophytic isolate contained nematicidal phenol (p-hydroxybenzoic acid, caffeic acid, Calycosin) and an alkaloid (Cyclopenin). These findings suggest that the isolated endophyte confers resistance to RKN in Solanum melongena by modulating host physiology and releasing nematicidal substances.

Potential of Exogenous Treatment with Dehydroascorbate to Control Root-knot Nematode Infection in Rice

Induced resistance (IR) is a unique physiological state characterized by reduced plant susceptibility to (a)biotic stress. Our previous studies showed that exogenous foliar application of dehydroascorbate (DHA), the oxidized form of ascorbic acid, induces systemic resistance against root-knot nematode Meloidogyne graminicola in rice. In the present study, the potential of DHA in protecting rice plants against M. graminicola was evaluated in lab, pot, and field studies. In an experiment where the interval between foliar treatment and inoculation was varied, 20 mM DHA was found to protect rice plants from M. graminicola for at least 14 days. Pot and field studies confirmed that 10 or 20 mM DHA are highly effective in reducing gall formation and led to a significant increase in rice seed yield. A half dose of DHA (10 mM) combined with another IR-stimulus - piperonylic acid (PA) 300 µM - was at par with DHA 20 mM, leading to reductions in gall formation of more than 80%. In in vitro bioassays, DHA was found to be highly nematicidal to the second-stage juveniles of M. graminicola, with more than 90% mortality within 3 h of exposure to 10 or 20 mM concentrations. While seed treatment had no effect, root drenching or root dipping was also effective in reducing rice susceptibility to M. graminicola, next to foliar treatment. As a dual-action compound with extended protection and ease of application, DHA has great potential for effective nematode management in rice.

Microbes vs. Nematodes: Insights into Biocontrol through Antagonistic Organisms to Control Root-Knot Nematodes.

Root-knot nematodes (Meloidogyne spp.) are sedentary endoparasites that cause severe economic losses to agricultural crops globally. Due to the regulations of the European Union on the application of nematicides, it is crucial now to discover eco-friendly control strategies for nematode management. Biocontrol is one such safe and reliable method for managing these polyphagous nematodes. Biocontrol agents not only control these parasitic nematodes but also improve plant growth and induce systemic resistance in plants against a variety of biotic stresses. A wide range of organisms such as bacteria, fungi, viruses, and protozoans live in their natural mode as nematode antagonists. Various review articles have discussed the role of biocontrol in nematode management in general, but a specific review on biocontrol of root-knot nematodes is not available in detail. This review, therefore, focuses on the biocontrol of root-knot nematodes by discussing their important known antagonists, modes of action, and interactions.

Biocontrol Potential of Neem leaf Extract on Mortality of Meloidogyne incognita

Root-knot nematode Meloidogyne incognita is one of the widely distributed in India and most economically damaging genera in vegetable crops. Plant products are the safer alternative approaches to control root knot nematodes. An experiment was carried out in vitro to test the Neem leaf extract of aqueous, acetone and methanol extract. Different concentrations of shade-dried leaves of Neem were tested on mortality of Meloidogyne incognita juveniles. Increase in concentration and exposure period resulted in increased mortality rate of Juveniles of M. incognita. Methanol Neem leaf extract (5 ml concentration) proved to be the most effective among used aqueous, acetone and methanol neem leaf extract . After 48 hours exposure aqueous and methanol leaves extract showed 100% mortality while acetone neem leaves extract showed 100% mortality after 72 hours exposure of 5 ml concentration. Neemleaves 0.25 ml con. was the least effective among all con.

The effectiveness of Biofumigants from Brassicaceae and Non-Brassicaceae to control root knot Nematodes on tomato

Root-knot nematodes (Meloidogyne spp.) are considered as one of the main limiting factors in crop production systems. Currently, several eco-friendly root-knot nematodes control technologies have been developed, one of which is biofumigants. The purpose of this study was to determine the effectiveness of biofumigants from Brassicaceae and Non-Brassicaceae to control root-knot nematodes. The study was conducted using a one-factor Completely Randomized Design (CRD) with 5 treatments. The results showed that the application of biofumigants from both brassicaceae and non-brassicaceae had no significant effect on the height and number of leaves of tomato. The effectiveness of cabbage biofumigant suppressing the population of RKN in this study was 69.5% compared to control (untreatment). While the treatment of sorghum biofumigant was the better treatment as a biofumigant plant from Non-Brassicaceae with an effectiveness level of suppressing the population of RKN was 55.8% compared to control. While the effectiveness level of suppressing the population of RKN biofumigant tagetes was 36.6% compared to control.

Nematicidal activity of volatile organic compounds produced by Bacillus altitudinis AMCC 1040 against Meloidogyne incognita

The application of nematicidal microorganisms and their virulence factors provides more opportunities to control root-knot nematodes. Bacillus altitudinis AMCC 1040, previously isolated from suppressive soils, showed significant nematicidal activity, and in this study, nematicidal substances produced by Bacillus altitudinis AMCC 1040 were investigated. The results of the basic properties of active substances showed that these compounds have good thermal stability and passage, are resistant to acidic environment and sensitive to alkaline conditions. Further analysis showed that it is a volatile component. Using HS-SPME-GC/MS, the volatile compounds produced by Bacillus altitudinis AMCC 1040 were identified and grouped into four major categories: ethers, alcohols, ketone, and organic acids, comprising a total of eight molecules. Six of them possess nematicidal activities, including 2,3-butanedione, acetic acid, 2-isopropoxy ethylamine, 3-methylbutyric acid, 2-methylbutyric acid and octanoic acid. Our results further our understanding of the effects of Bacillus altitudinis and its nematicidal metabolites on the management of Meloidogyne incognita and may help in finding less toxic nematicides to control root knot nematodes.

Development of biorational management package of root knot nematode disease of country bean

A field experiment was conducted with a view to test the efficacy of Tricho-composts and integration of Tricho-composts, poultry refuse (PR), neem oilcake (NOC), saw dust burning (SDB) with chemical nematicide Furadan 5G (Carbofuran) for controlling root knot nematode of country bean through which growers will be benefited. The root-knot nematode infested soils were treated with Tricho-compost-1 @ 2 kg/pit, Tricho-compost-2 @ 2 kg/pit, Tricho-compost-1 @ 2 kg/pit + Furadan 5 G @ 20 g/pit, Tricho-compost-2 @ 2 kg/pit + Furadan 5 G @ 20 g/pit, poultry refuse @ 5-6 kg/pit + Furadan 5 G @20 g/pit , neem oil cake @ 500 g/pit + Furadan 5 G @ 20 g/pit and saw dust burning + Furadan 5 G @ 20 g/pit. It was revealed that all the treatments performed well in reducing root-knot nematode infestation and increasing plant growth and yield country bean compared to farmers’ practices. Among the treatments, integration of poultry refuse with Furadan 5G or Trichoderma based bio-fungicides Tricho-composts with Furadan 5G or neem oil cake with Furadan 5G are the best treatments in reducing root-knot nematode infestation and increasing plant growth as well as yield of country bean. Soil treatment with only Tricho-composts or integration of saw dust burning with Furadan 5G also performed better in reduction of root knot nematode disease and increasing plant growth as well as yield of country bean.

Development of Biorational Management Package of Root Knot Nematode Disease of Country Bean

A field experiment was conducted with a view to test the efficacy of Tricho-composts and integration of Tricho-composts, poultry refuse (PR), neem oilcake (NOC), saw dust burning (SDB) with chemical nematicide Furadan 5G (Carbofuran) for controlling root knot nematode of country bean through which growers will be benefited. The root-knot nematode infested soils were treated with Tricho-compost-1 @ 2 kg/pit, Tricho-compost-2 @ 2 kg/pit, Tricho-compost-1 @ 2 kg/pit + Furadan 5 G @ 20 g/pit, Tricho-compost-2 @ 2 kg/pit + Furadan 5 G @ 20 g/pit, poultry refuse @ 5-6 kg/pit + Furadan 5 G @20 g/pit , neem oil cake @ 500 g/pit + Furadan 5 G @ 20 g/pit and saw dust burning + Furadan 5 G @ 20 g/pit. It was revealed that all the treatments performed well in reducing root-knot nematode infestation and increasing plant growth and yield country bean compared to farmers’ practices. Among the treatments, integration of poultry refuse with Furadan 5G or Trichoderma based bio-fungicides Tricho-composts with Furadan 5G or neem oil cake with Furadan 5G are the best treatments in reducing root-knot nematode infestation and increasing plant growth as well as yield of country bean. Soil treatment with only Tricho-composts or integration of saw dust burning with Furadan 5G also performed better in reduction of root knot nematode disease and increasing plant growth as well as yield of country bean.

Genetic improvement of Pseudomonas aeruginosa and Bacillus cereus for controlling root knot nematode and two weeds under laboratory conditions

Genetic improvement of Pseudomonas aeruginosa and Bacillus cereus for controlling root knot nematode and two weeds under laboratory conditions

Allelopathic effects of mustard cake to control root knot nematode (Meloidogyne graminicola Golden & Birchfield 1965) in rice

Allelopathic effects of mustard cake to control root knot nematode (Meloidogyne graminicola Golden & Birchfield 1965) in rice

Biocontrol potential of Bacillus altitudinis AMCC1040 against root-knot nematode disease of ginger and its impact on rhizosphere microbial community

Root knot nematodes are one of the most destructive hemibiotrophic root pathogens that can cause ginger bark cracking disease in ginger planting areas around the world. There is an urgent need for sustainable alternatives methods, such as biological control. The nematicidal activity of Bacillus altitudinis AMCC1040 has been previously shown in vitro and in pot experiments. Here, field experiments were conducted to evaluate the biocontrol potential of Bacillus altitudinis AMCC1040 against ginger bark cracking disease, and to evaluate its ability to colonize the rhizosphere. In addition, we also evaluated its impact on the rhizosphere microbial communities. The results of biocontrol experiments demonstrated that the application of Bacillus altitudinis AMCC1040 can significantly inhibit nematode reproduction, inhibit root galling and reduce the severity of ginger bark cracking disease. In addition, Bacillus altitudinis AMCC1040 colonized steadily in ginger rhizosphere soil ranging from 5.08 to 5.49 Log10 CFU g−1 soils. Compared with fosthiazate (One of the most commonly used nematicides in China), Bacillus altitudinis AMCC1040 performed better in terms of bio-safety. Meanwhile, the taxa enriched in Bacillus altitudinis AMCC1040 treatment were found in Actinobacteria, Gemmatimonadetes and Firmicutes. This study demonstrated that Bacillus altitudinis AMCC1040 have a strong potential to control ginger bark cracking disease in the field. These results provide strong support for further exploration of the application of Bacillus spp. as biocontrol agents to control root knot nematodes in many crops. Furthermore, the occurrence of ginger bark cracking disease described in this study will be of great help to future prevention and control measures.

Parasitic nematodes of wild and cultivated subtropical fruit plants in Central Asia

The purpose of the research is studying the species composition and control measures against parasitic nematodes of wild and cultivated subtropical fruit plants of Central Asia.Materials and methods. We studied subtropical fruit crops in 198 farms and 1985 household plots located in various soil and climatic zones of over 20,675 hectares in Central Asia. The materials were collected in the autumn (September-October), spring (April-May) and summer (June-August) months in 1970–1990 by the route method. Study subjects were plant parasitic nematodes of 8 species of wild and cultivated subtropical fruit plants in the Central Asian republics. A modified Baermann funnel method was used to isolate plant nematodes from plants and soil near roots. In total, we collected and analyzed more than 5,400 plant and soil samples. To identify the species of plant parasitic nematodes, we used the Atlas of plant parasitic nematodes compiled at the Institute of Parasitology of the Russian Academy of Sciences, as well as morphometric indicators obtained according to the generally accepted De Mann formulae.Results and discussion. More than 129,000 specimens of plant parasites of 98 species were found in the studied wild and cultivated subtropical fruit crops and soil near their roots. In many farms of the Central Asian republics, we found southern root-knot nematodes, peanut root-knot nematodes, javanese root-knot nematodes, and cotton root-knot nematodes in mixed populations. In Uzbekistan, the prevalence in these crops was from 8 to 61.3%, in Tajikistan – from 78 to 98%, in Turkmenistan – from 6 to 98%, and in Kyrgyzstan – 33%. In addition to root-knot nematodes, representatives of ecto- and endoparasites of the genera Tylenchorhynchus, Merlinius, Quinisulcius, Rotylenchus, Helicotylenchus, Pratylenchus, Paratylenchus, Macroposthonia, Labocriconema and Xiphinema were parasitizing in the above subtropical cultures. Under production conditions, we tested Furadan at a dose of 40 kg/ha, Heterophos at a dose of 60 and 120 kg/ha, and Aldicarb at a dose of 40 kg/ha to control root-knot and other parasitic nematodes. Their efficacy ranged from 89 to 100%. We also used the soil solarization method developed by us, the efficacy of which was 95–98%.

Potensi Beberapa Isolat Bakteri Endofit untuk Pengendalian Biologi Meloidogyne graminicola pada Tanaman Padi

Meloidogyne graminicola merupakan salah satu nematoda parasit penting pada tanaman padi. M. graminicola menyebabkan gejala puru pada akar sehingga pertumbuhan tanaman terhambat dan terganggu. Pengendalian M. graminicola sangat penting dilakukan agar kerusakan pada tanaman padi dan penyebarannya dapat ditekan. Penelitian ini bertujuan untuk menguji potensi bakteri endofit dalam mengendalikan nematoda puru akar (NPA) M. graminicola pada tanaman padi. Empat isolat bakteri endofit asal tanaman padi, yaitu isolat Si33, Si2, Sp24, GH1, dan satu isolat asal tanaman kentang G053 diuji untuk melihat pengaruhnya terhadap mortalitas M. gramincola secara in vitro dan kemampuannya dalam menekan serangan M. graminicola pada tanaman padi di rumah kaca. Hasil uji kultur filtrat bakteri endofit secara in vitro terbukti efektif meningkatkan kematian juvenil 2 M. graminicola sebesar 99.5% hingga 100%. Isolat bakteri endofit juga mampu menekan jumlah puru akar pada tanaman padi dengan kisaran 42.2%–49.3% pada percobaan di rumah kaca. Hasil penelitian ini mengindikasikan bahwa isolat bakteri endofit yang digunakan dalam penelitian ini mempunyai potensi yang baik sebagai agens biokontrol untuk mengendalikan M. graminicola pada tanaman padi.

Nematode Extract and Acaciasides Use as Preventive Biomedicines Against Plant Diseases: Improved Earth-Environmental-Health-Research Science-TechnologyCommunication and May be Controlled 21st-Century Pandemic Diseases!

Traditional chemical control using chemical pesticides available for the last few decades is in a declining status internationally. Thus, there remains a need for developing effective biomedicines which would be cheap, non-phytotoxic, and non-pollutant. Animal-biomedicine, Nematode extract (NE) of the females of Meloidogyne incognita @ 0.14 mg/ plant- and plant-biomedicines, acaciasides (A and B; two triterpenoid saponins) isolated from the funicles of Acacia auriculiformis @ 20 mg/plant, applied by foliar spray on okra plants (Abelmoschus esculentus L. Cv. Ankur-40) reduced M. incognita and yellow vein mosaic virus (YVMV) infection of the host plants and enhanced their growth. Treatment with NE followed by the application of acaciasides gave better control of root-knot and YVMV diseases and promoted higher growth of plants. The protein content of fruits has also been increased in both cases. Using double the dose of acaciasides alone, by foliar spray and soil drench gave no better results with respect to the control of nematodes and viral diseases and growth of the test plants. An analysis of protein, by electrophoresis and densitometer scanning of the test plants, showed that treatment with both the extracts resulted in the increased number of proteins in the roots. This indicates that both the extracts can induce the expression of some new pathogenesis-related (PR) proteins, which might have inhibited nematodes and YVMV infection like plant diseases. So, Nematode extract and acaciasides use as preventive potential biomedicines against plant diseases by improving agriculture, crop production, toxic-free earth-environmental-health and research, science-technology, and communication, and may be controlled 21st-century pandemic diseases by increasing natural immunity. And in the future synthetic production of biomedicine-NE will be cost-effective, easily maintainable supply-chains, accurate information, plans for ensuring sustainable developments, continuous supply of essential medicines by improving the biomedicines for the benefit of public health with the development of earth-environmental-health and research.

Management of Meloidogyne incognita in Capsicum by Trichoderma viride and Organic Amendments under Protected Cultivation

A study was conducted to assess the effect of individual and combined application of Trichoderma viride and other organic amendments on plant growth and nematode multiplication parameters in comparison with chemical, carbofuran 3G and untreated check for management of root-knot nematodes under polyhouse in Bihar. Maximum improvement in the plant growth parameters was observed with combined application of T. viride @ 10 g/pot + neem cake @ 100 g/pot. Carbofuran 3G @ 2 kg a.i./ha was found most effective in controlling root knot nematodes. T. viride @ 10 g/pot + neem cake @ 100 g/pot increased crop yield by 77 %, compared to 60 % with carbofuran. Neem cake had increased the efficiency of the biocontrol agent, which might be partially due to reduction in nematode population by the action of toxicity of fungal bio agents and partly to the fact that neem cake additive served as manure for management of M. incognita.

Fortified bacterial consortium – A novel approach to control root knot nematode in cucumber (cucumis sativum)

In present era of organic farming, biocontrol agents can be further improved to obtain greater levels of disease reduction. Development of formulations with increased shelf life and broad spectrum action with consistent performance under field conditions could pave the way for commercialization of the technology at a faster rate. In present investigation plant growth promoting rhizobacterial (PGPR) consortium containing three biocontrol bacterial strains (Providencia vermicola AAU PR1 (NCBI ACCN: KJ161325), Pseudomonas putida AAU PR2 (NCBI ACCN: KJ161326) and Pseudomonas fluorescens AAU PR3 (NCBI ACCN: KJ161327) fortified with extracts of botanicals viz. Azadirachta indica (neem), Ipomoea carnea (besharam) and Brassica juncea (mustard cake) was prepared and found to effectively control M. incognita under laboratory conditions and displayed highest reduction in egg hatching after 24, 48 and 72 h of exposure. Seed coating + soil drenching of fortified PGPR consortium was found to enhance plant growth parameters and reduce root knot nematode infestation in cucumber in pot experiment as well as field. Opinion of farmers growing cucumber in protected cultivation (polyhouse / greenhouse) indicated that application of fortified PGPR consortium reduced nematode infestation and replaced chemical measures of nematode control and showed increase in yield providing dual benefit of reducing cost of cultivation with higher yield. All the experimental results signified the efficiency of fortified PGPR consortium for control of root knot nematode disease in cucumber.

Recent Advances in the Development of Environmentally Benign Treatments to Control Root-Knot Nematodes.

Root-knot nematodes (RKNs), Meloidogyne spp., are sedentary endoparasites that negatively affect almost every crop in the world. Current management practices are not enough to completely control RKN. Application of certain chemicals is also being further limited in recent years. It is therefore crucial to develop additional control strategies through the application of environmentally benign methods. There has been much research performed around the world on the topic, leading to useful outcomes and interesting findings capable of improving farmers’ income. It is important to have dependable resources gathering the data produced to facilitate future research. This review discusses recent findings on the application of environmentally benign treatments to control RKN between 2015 and April 2020. A variety of biological control strategies, natural compounds, soil amendments and other emerging strategies have been included, among which, many showed promising results in RKN control in vitro and/or in vivo. Development of these methods continues to be an area of active research, and new information on their efficacy will continuously become available. We have discussed some of the control mechanisms involved and suggestions were given on maximizing the outcome of the future efforts.

NEMATICIDAL EFFICACY OF BIOFUMIGATION WITH VARIOUS BRASSICA CROPS AGAINST Meloidogyne Incognita (KOFOID ET WHITE) CHITW. ON TOMATO CROP IN NORTH SINAI

Biofumigation is the practice of using Brassica green manure plants with high content of glucosinolates which enzymatically hydrolyses to nematicidal isothiocynate (ITCs) compounds. Brassica species as well as cultivars differ in both type and concentration of glucosinolate (GSLs). Under North Sinai conditions, however, the highly effective amongst Brassica species that can be effectively used are not documented for specific target yet. In this study two successive field trials were conducted using tomato (cv. Elysa) aimed at evaluating and determining the efficacy of four Brassica species (Fodder radish (Raphanus sativus) TERRANOVA H-4-169/0300), Canola (Brassica napus) (cv. Serow 4), Mustard (Brassica alba) (local commercial cultivar) and Rocket Salad (Eruca sativa((local commercial cultivar) in comparison with vydate (as positive control) and untreated (as a negative control) in suppressing root knot nematode population (Meloidogyne incognita), reproductive factor and galling index as studied nematode parameters. After 2 weeks of tomato seedlings transplanting both root knot nematode population and reproductive factor were recorded. After termination of the two experiments (12 weeks) nematode parameters and tomato plant growth attributes were recorded. Fodder radish was significantly the most effective brassica green manure in controlling root knot nematodes (Meloidogyne incognita) compare to other three studied brassicas. All studied parameters of fodder radish green manure were comparable with that of vydate. The study recommends that biofumigation methods using fodder radish green manure can be used through integrated pest management program (IPM) for both conventional and organic agriculture tomato production systems.

Effect of Mi Gene and Nematode Resistance on Tomato Genotypes Using Molecular and Screening Assay

The Mi gene is known to involve in the resistance response to some Root knot nematodes, Meloidogyne spp. in tomato plants Lycopersicon esculentum. Root knot nematodes cause significant damages to almost all crops in the world. Among Meloidogyne species, Meloidogyne incognita is one of the most damages species causing a vast amount of crop loss including tomato plants. The resistance gene may be found in some tomato genotypes or cultivars. Determining the resistance gene, Mi, in tomato cultivars is very important to control root knot nematodes. For this purpose, this study was conducted in 99 tomato genotypes that were screened for resistance against Meloidogyne incognita in molecular and screening assays. Results revealed that Mi gene was only determined in one genotype (Tom113). The result of the screening assay indicated that one of the genotypes (Tom113) showed an immune reaction against the nematode; two genotypes (Tom146, Tom141) were found intermediate; 17 genotypes moderately susceptible, 43 genotypes susceptible and 36 genotypes found highly susceptible. Results of the screening assay confirmed the presence of Mi gene in a tomato genotype, which accompanied with a decreased ability for the nematode in causing the infection. Immune and some promising genotypes are thought as important genetic tools for breeding studies for future works.

Effect of combined soil application of biochar and oilcakes on Meloidogyne incognita infesting lentil (Lens culinaris cv. Desi)

Soil amendment with biochar is widely used to improve soil fertility and crop productivity. However, its effect on plant nematodes has not been examined properly. The present study investigates the effects of biochar on root knot nematode, Meloidogyne incognita under in planta conditions. In pots experiment, biochar (45 g) when paired with oil cakes (15 g) suppressed the M. incognita and improved the plant growth of tested plant. Significant suppression in nematode infestation in terms of egg masses and eggs by (56.0 and 52.7%) and maximum improvement in plant growth in plant length and dry weight by 74.1 and 63.8%, respectively was observed when combined soil application of biochar and mustard cake was applied in the soil. The effect was least when biochar was applied alone. The study has suggested that biochar amendment along with mustard oil cake can control root knot nematode infestation in lentil.