Pathogenicity and Metabolites of Endoparasitic Nematophagous Fungus Drechmeria coniospora YMF1.01759 against Nematodes

Plant parasitic nematodes cause severe damage to crops. Endoparasitic nematophagous fungi (ENF) are a type of important biocontrol fungi, which can cause disease or kill nematodes by producing various spores. As a major ENF, Drechmeria coniospora displays certain potential for controlling plant-parasitic nematodes. In this study, the pathogenicity and secondary metabolites of the endoparasitic fungus D. coniospora YMF1.01759 were investigated. The strain D. coniospora YMF1.01759 had high infection efficiency against nematodes. The process of infecting nematodes by the strain was observed under an electron microscope. Here, 13 metabolites including one new compound 4(S)-butoxy-3-(butoxymethyl)-2-hydroxycyclopent-2-en-1-one (2) were isolated and identified from the fermentation products of D. coniospora YMF1.01759 cultured in a SDAY solid medium. Furthermore, a bioassay showed that 5-hydroxymethylfuran-2-carboxylic acid (1) is toxic to the root knot nematode Meloidogyne incognita and affects the hatching of its egg. Thereby, the nematicidal mortality attained 81.50% at 100 μg/mL for 48 h. Furthermore, egg hatching was inhibited at the tested concentrations, compared with water control eggs. This is the first report on the secondary metabolites of the ENF D. coniospora. The results indicated that D. coniospora could infect nematodes by spores and produce active metabolites to kill nematodes. The biological control potential of D. coniospora against nematodes was expounded further.

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Screening of anti-nematode potential through inhibition of egg hatching in plant-parasitic nematode Meloidogyne javanica

Current Botany ◽

10.25081/cb.2020.v11.6172 ◽

2020 ◽

pp. 93-98

Author(s):

Shilpy Shakya ◽

Bindhya Chal Yadav

Keyword(s):

Management Strategies ◽

Plant Defence ◽

Meloidogyne Javanica ◽

Parasitic Nematodes ◽

Aqueous Extracts ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Leaf Extracts ◽

Egg Hatching ◽

Plant Parasitic

Plant-parasitic nematodes have emerged as nature’s most successful among all parasites known till today. These animals have been reported from all terrains of all ecosystems. Their capability to survive on a wide diversity of the host plants, circumvent host plant defence is a few of several of their secrets making them most successful of all known parasites. Among various groups of plant-parasitic nematodes, endo-parasitic nematodes are the most damaging one and also difficult to control. Meloidogyne sps. are commonly known as root-knot nematodes. Our inability to control them is primarily due to our poor understanding of the biology of these plant parasites. Due to the availability of the complete genome sequence of few Meloidogyne species, biotechnological interventions are used to unravel the secrets of their success. Chemical controls of these nematodes are extensively reported in the literature. Due to the environmental toxicity associated with these chemicals, and restrictions on the use of chemicals against nematodes led to screening and development of eco-friendly management strategies. The present study was conducted to screen nematotoxic properties of Neem (Azadirachta indica), Jatropha (Jatropha curcas), Kachnar (Bauhinia variegate), Bel (Aegle marmelos) and Eucalyptus (Eucalyptus globules) leaf extracts against root-knot nematode Meloidogyne javanica in vitro. The aqueous extracts were used against the hatching of the nematode eggs, movement of second stage juveniles (J2) and the viability of the J2 in increasing concentration of the bioactive compound. The eggs were treated with various concentrations of the selected extracts for different time periods ranging from 24h to 6 days. A significant inhibition of egg hatching and increase in the mortality of the nematode juvenile in few of the aqueous extracts were recorded. Reduced egg hatching and increased mortality of the nematode juveniles could be maybe the indicators of the presence of anti-nematode potential in the selected plant leaves. The results from the study can pave the way for the development of eco-friendly management strategies for plant-parasitic nematodes.

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Toward genetic modification of plant-parasitic nematodes: delivery of macromolecules to adults and expression of exogenous mRNA in second stage juveniles

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkaa058 ◽

2021 ◽

Vol 11 (2) ◽

Author(s):

Olaf Kranse ◽

Helen Beasley ◽

Sally Adams ◽

Andre Pires-daSilva ◽

Christopher Bell ◽

...

Keyword(s):

Food Security ◽

Genetic Modification ◽

The Body ◽

Forward Genetics ◽

Heterodera Schachtii ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Cyst Nematodes ◽

Plant Parasitic

Abstract Plant-parasitic nematodes are a continuing threat to food security, causing an estimated 100 billion USD in crop losses each year. The most problematic are the obligate sedentary endoparasites (primarily root knot nematodes and cyst nematodes). Progress in understanding their biology is held back by a lack of tools for functional genetics: forward genetics is largely restricted to studies of natural variation in populations and reverse genetics is entirely reliant on RNA interference. There is an expectation that the development of functional genetic tools would accelerate the progress of research on plant-parasitic nematodes, and hence the development of novel control solutions. Here, we develop some of the foundational biology required to deliver a functional genetic tool kit in plant-parasitic nematodes. We characterize the gonads of male Heterodera schachtii and Meloidogyne hapla in the context of spermatogenesis. We test and optimize various methods for the delivery, expression, and/or detection of exogenous nucleic acids in plant-parasitic nematodes. We demonstrate that delivery of macromolecules to cyst and root knot nematode male germlines is difficult, but possible. Similarly, we demonstrate the delivery of oligonucleotides to root knot nematode gametes. Finally, we develop a transient expression system in plant-parasitic nematodes by demonstrating the delivery and expression of exogenous mRNA encoding various reporter genes throughout the body of H. schachtii juveniles using lipofectamine-based transfection. We anticipate these developments to be independently useful, will expedite the development of genetic modification tools for plant-parasitic nematodes, and ultimately catalyze research on a group of nematodes that threaten global food security.

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The role of plant-parasitic nematodes in reducing yield of sugarcane in fine-textured soils in Queensland, Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea05287 ◽

2007 ◽

Vol 47 (5) ◽

pp. 620 ◽

Cited By ~ 22

Author(s):

B. L. Blair ◽

G. R. Stirling

Keyword(s):

Growth And Yield ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Population Densities ◽

Lesion Nematode ◽

Yield Responses ◽

The Impact ◽

Stalk Length ◽

Plant Parasitic

Damage to sugarcane caused by root-knot nematode (Meloidogyne spp.) is well documented in infertile coarse-textured soils, but crop losses have never been assessed in the fine-textured soils on which more than 95% of Australia’s sugarcane is grown. The impact of nematodes in these more fertile soils was assessed by repeatedly applying nematicides (aldicarb and fenamiphos) to plant and ratoon crops in 16 fields, and measuring their effects on nematode populations, sugarcane growth and yield. In untreated plant crops, mid-season population densities of lesion nematode (Pratylenchus zeae), root-knot nematode (M. javanica), stunt nematode (Tylenchorhynchus annulatus), spiral nematode (Helicotylenchus dihystera) and stubby-root nematode (Paratrichodorus minor) averaged 1065, 214, 535, 217 and 103 nematodes/200 mL soil, respectively. Lower mean nematode population densities were recorded in the first ratoon, particularly for root-knot nematode. Nematicides reduced populations of lesion nematode by 66–99% in both plant and ratoon crops, but control of root-knot nematode was inconsistent, particularly in ratoons. Nematicide treatment had a greater impact on shoot and stalk length than on shoot and stalk number. The entire community of pest nematodes appeared to be contributing to lost productivity, but stalk length and final yield responses correlated most consistently with the number of lesion nematodes controlled. Fine roots in nematicide-treated plots were healthier and more numerous than in untreated plots, and this was indicative of the reduced impact of lesion nematode. Yield responses averaged 15.3% in plant crops and 11.6% in ratoons, indicating that nematodes are subtle but significant pests of sugarcane in fine-textured soils. On the basis of these results, plant-parasitic nematodes are conservatively estimated to cost the Australian sugar industry about AU$82 million/annum.

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Peach Root-knot Nematode

EDIS ◽

10.32473/edis-hs1230-2018 ◽

2018 ◽

Vol 2018 (4) ◽

Author(s):

Mary Ann D. Maquilan ◽

Ali Sarkhosh ◽

Donald W. Dickson

Keyword(s):

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

The Subject ◽

Plant Parasitic

One of the production issues that peach growers in Florida must contend with is plant-parasitic nematodes. One such species is the more recently discovered peach root-knot nematode, Meloidogyne floridensis, which is the subject of this 5-page publication. Written by Mary Ann D. Maquilan, Ali Sarkhosh, and Donald Dickson and published by the UF/IFAS Horticultural Sciences Department, July 2018. http://edis.ifas.ufl.edu/hs1320

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Biochemical Analysis Based on Zinc Uptake of Chickpea (Cicer arietinum L.) Varieties Infected by Meloidogyne incognita

International Journal of Plant & Soil Science ◽

10.9734/ijpss/2021/v33i2430767 ◽

2021 ◽

pp. 186-192

Author(s):

Pranaya Pradhan ◽

Dhirendra Kumar Nayak ◽

Manaswini Mahapatra

Keyword(s):

Cicer Arietinum ◽

Zinc Content ◽

Cost Effective ◽

Zinc Uptake ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Cicer Arietinum L ◽

Chickpea Plant ◽

Plant Parasitic

The significant constraints in Chickpea (Cicer arietinum L.) production hampers a bit more than 14% global yield loss due to plant-parasitic nematodes. Root-knot nematode (Meloidogyne sp.) is an endoparasite and a significant species affecting the chickpea plant. So, the chemical basis of management is more cost-effective, and pest resurgence building is enhanced in the pathogen. So, ecological-based nematode management is requisite, which also is got hampered due to breeding for resistance against such plant-parasitic nematodes. This was the primary reason to conduct this experiment to enhance resistance in the chickpea plants based on Zinc uptake by using bioagent, Pseudomonas fluorescens alone or in combination. where Different treatments including nematode, bacterium, and chemicals were used sustaining the enhancement of disease resistance in chickpea cultivars, RSG 974, GG 5, GNG 2144. Zinc content of chickpea variety GNG 2144 was found the highest in treatment, when only bacterium (P. fluorescens) was inoculated, i.e., 3.14 mg/100g of root followed by GG 5, i.e., 2.79 mg/100g of root and RSG 974 was, i.e., 2.35 mg/100g of root respectively in a descending order. Application of P. fluorescence combined or alone gradually increased the Zn concentration in roots of chickpea plants compared to healthy check followed by chemical treated plants.

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Short-Term Effects of Sublethal Doses of Nematicides on Meloidogyne incognita

Phytopathology ◽

10.1094/phyto-11-18-0420-r ◽

2019 ◽

Vol 109 (9) ◽

pp. 1605-1613 ◽

Cited By ~ 10

Author(s):

Catherine L. Wram ◽

Inga A. Zasada

Keyword(s):

Population Density ◽

Meloidogyne Incognita ◽

Cultivated Plants ◽

Parasitic Nematodes ◽

Initial Population ◽

Plant Parasitic Nematodes ◽

Water Control ◽

Effective Doses ◽

Sublethal Doses ◽

Plant Parasitic

Meloidogyne species are one of the most important groups of plant-parasitic nematodes globally because of their ability to damage most cultivated plants. Although they are widespread and economically important, there are limited control measures to combat these nematodes. New nonfumigant nematicides have been discovered that have the potential to be widely utilized for the management of plant-parasitic nematodes. Because of the longer half-lives in soil and lower toxicity of new nematicides compared with traditional fumigant and nonfumigant nematicides, understanding how nematodes respond to sublethal doses of nematicides is imperative to understanding whether nematicide resistance has the potential to develop. Characterizing responses of nematodes to sublethal doses will provide the foundation for future work, such as gene expression studies. In this study, the nematicides oxamyl (Vydate), fluazaindolizine (Salibro), fluensulfone (Nimitz), and fluopyram (Velum), were evaluated to understand how sublethal doses affect the fecundity and mobility of Meloidogyne incognita second-stage juveniles (J2). Using a microwell assay system, dose-response curves for each nematicide were established for M. incognita J2. Fluopyram was the most toxic nematicide, with effective doses up to 230 times lower than that of other nematicides. The other nematicides had predicted ED50 values (effective doses that resulted in 50% of the population becoming inactive) of 89.4, 131.7, and 180.6 ppm for oxamyl, fluensulfone, and fluazaindolizine, respectively. The 24-h ED50 of each nematicide was then used in both motility and infectivity assays. The motility and activity of M. incognita J2 exposed to ED50 doses of fluazaindolizine and fluensulfone was significantly reduced, with nematodes initially being motile but eventually becoming inactive. However, the motility of M. incognita J2 exposed to ED50 doses of fluopyram and oxamyl was not different from a water control. In a pot assay, M. incognita J2 exposed to ED50 doses of fluazaindolizine, oxamyl, and fluensulfone were unable to reproduce on tomato, with reproduction factors (RF = final population density/initial population density) of 0 to 0.03. Fluopyram did not reduce reproduction of M. incognita, with a mean RF of 38.7 ± 4.5, which was similar to the RF of 46.3 ± 4.6 for the water control. This study is the first comprehensive evaluation of M. incognita activity, motility, and fecundity after exposure to the traditional nematicide, oxamyl, as well as three new nematicides, fluazaindolizine, fluopyram, and fluensulfone.

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Population dynamics of plant parasitic nematodes in Queensland pineapple fields and the effects of these nematodes on pineapple production

Australian Journal of Experimental Agriculture ◽

10.1071/ea9930197 ◽

1993 ◽

Vol 33 (2) ◽

pp. 197 ◽

Cited By ~ 3

Author(s):

GR Stirling ◽

A Nikulin

Keyword(s):

Population Dynamics ◽

Population Density ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Ratoon Crop ◽

Original Population ◽

Ethylene Dibromide ◽

Nematode Population Density ◽

Plant Parasitic

Twelve pineapple fields with various densities of root-knot nematode were selected during a ratoon crop. Nematode populations were monitored regularly after the crop was ploughed out. Regardless of the original population density, rootknot nematodes were almost nondetectable at the end of the subsequent 3-6-month fallow intercycle period. In the absence of nematicide treatment there were marked differences between sites in the manner in which rootknot nematodes increased in the newly planted crop. At some sites, they were detectable 9-15 months after planting, whereas at other sites, nematodes were not observed at 15 months. Increases in ratoon crop yield following application of ethylene dibromide or fenamiphos were related to root-knot nematode population density. Significant increases in yield were not obtained at sites where the nematode was not detectable at 15 months. The results suggest that some pineapple growers are needlessly applying nematicides and that nematode diagnostic services should be developed to provide growers with advice on their nematode management programs.

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Resistance and tolerance of grapevine rootstocks to plant parasitic nematodes in vineyards in north-east Victoria

Australian Journal of Experimental Agriculture ◽

10.1071/ea9890129 ◽

1989 ◽

Vol 29 (1) ◽

pp. 129 ◽

Cited By ~ 4

Author(s):

M Edwards

Keyword(s):

Large Population ◽

Parasitic Nematodes ◽

Cabernet Sauvignon ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

North East ◽

Tylenchulus Semipenetrans ◽

Effect On Yield ◽

Citrus Nematode ◽

Plant Parasitic

Three grapevine rootstock trials in North-East Victoria, Australia, were sampled over several summers to determine nematode populations and the resistance or the tolerance of some commonly used winegrape varieties and rootstocks to plant parasitic nematodes. Rootstocks on which nematodes failed to reproduce or reproduced poorly were considered resistant, rootstocks which supported high populations of nematodes with no apparent effect on yield were considered tolerant. Susceptible rootstocks supported high numbers of nematodes and yielded poorly. The varieties studied were: Shiraz, Chardonnay, Cabernet Sauvignon; and the rootstocks were: Harmony, Richter 110, Schwarzmann, ARG No. 1, 5A Teleki, Rupestris du Lot, 5BB Kober, SO4, Ramsey, K5 1-32 and 1202. The plant parasitic nematodes found on the trial sites were root-knot (Meloidogyne javanica (Treub) Chitwood) and citrus (Tylenchulus semipenetrans Cobb) nematodes. Cabernet Sauvignon, Chardonnay, Shiraz and ARG No. 1 were susceptible to the root-knot nematode. Harmony exhibited tolerance to the citrus nematode and was a good host, allowing a large population to build up. Ramsey appeared to be resistant to the citrus nematode, at least in the Cabernet Sauvignon rootstock trial at Wahgunyah.

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Construction of artificial microRNA expression vectors for inhibition of Minc16281 gene in root-knot nematode Meloidogyne incognita

The Journal of Agriculture and Development ◽

10.52997/jad.8.04.2019 ◽

2019 ◽

Vol 18 (4) ◽

pp. 62-69

Author(s):

Phong V. Nguyen

Keyword(s):

Meloidogyne Incognita ◽

Parasitic Nematode ◽

Expression Vectors ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Gene Encoding ◽

Soybean Field ◽

Genes Encoding ◽

Plant Parasitic

Effectors have been identified to play a very important role in the parasitism of plant-parasitic nematode. To cope with this type of pathogen, many approaches of silencing genes encoding for effectors have been studied and promise to be an effective tool to create plant varieties resistant to plant-parasitic nematodes. In this study, the Minc16281 gene encoding a pioneer effector with unknown function was determined and cloned from a Meloidogyne incognita population isolated from soybean field (ID: MH315945.1). The nucleotide sequence of this gene showed 97% identity to its homolog in GenBank (ID: JK287445.1) used as the control strain in our research. To generate host-induced gene silencing constructs which can potentially silence the expression of Minc16281 gene, two artificial microRNAs were synthesized based on the miR319a structure of Arabidopsis thaliana and inserted into an expression vector in soybean. These microRNAs can be introduced into soybean to investigate the function of Minc16281 on parasitism of root-knot nematode.

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Community Analysis of Nematodes Associated with Banana, Identification of root knot nematode and Evaluation the Susceptibility of Some Cultivars to Infection

10.21203/rs.3.rs-740928/v1 ◽

2021 ◽

Author(s):

Radwa G. Mostafa ◽

Aida M. El-Zawahry ◽

Ashraf E. M. Khalil ◽

Ameer E. Elfarash ◽

Ali D. A. Allam

Keyword(s):

Meloidogyne Javanica ◽

Nematode Species ◽

Common Species ◽

Molecular Techniques ◽

Control Measures ◽

Parasitic Nematodes ◽

Plant Parasitic Nematodes ◽

Root Knot Nematode ◽

Root Knot Nematodes ◽

Plant Parasitic

Abstract Background Plant-parasitic nematodes are extremely dangerous pests in a variety of economically important crops. The purpose of this study was a survey of all nematode species existing in banana from three sites in Assiut Governorate, Egypt and to characterize the most common species by morphological, morphometric and molecular techniques (PCR with species-specific primers). Then, study of resistance or sensitivity of some banana cultivars to root-knot nematodes.Methods and Results Four nematodes, Meloidogyne, Rotylenchulus reniformis, Helicotylenchus and Pratylenchus were isolated and identified from soil and root samples collected from banana plants. Most frequently occurring of plant parasitic nematode species in banana was Meloidogyne. Former research found differences in species and in resistance to root-knot nematodes among the examined plant cultivars. Identification of Root-knot nematodes by Characterize of morphometric, molecularly, morphological isolate of Meloidogyne related to banana plants. The results revealed that the identified nematode species, Meloidogyne javanica, is the most common plant-parasitic nematodes in all locations. Data on the susceptibility of the tested banana cultivars to M. javanica revealed that Grand Naine was highly susceptible (HS) however, Magraby was susceptible (S) but Williams and Hindi cultivars were moderately resistant (MR).Conclusions we concluded that a survey revealed the significant prevalence of Meloidogyne javanica, the most important nematodes on banana in Assiut. The morphometric, morphological, and molecular identification were harmonic with one another. In addition to the host response of certain banana cultivars, to M. javanica that resistance is of significance and can be helpful to incorporate through planning control measures for root- knot nematodes.

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