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

2020 ◽  
pp. 93-98
Author(s):  
Shilpy Shakya ◽  
Bindhya Chal Yadav

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.

2021 ◽  
Author(s):  
Radwa G. Mostafa ◽  
Aida M. El-Zawahry ◽  
Ashraf E. M. Khalil ◽  
Ameer E. Elfarash ◽  
Ali D. A. Allam

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.


EDIS ◽  
2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Mengyi Gu ◽  
Johan Desaeger

Florida leads the commercial production of caladiums, a popular ornamental. In Florida, root-knot, sting, and stubby root nematodes are found in caladium fields. Root-knot nematodes are considered the most important of all pests in caladiums that are grown in sand. This publication will help caladium growers understand what plant-parasitic nematodes are and current nematode management strategies for the caladium industry.


Plant Disease ◽  
2004 ◽  
Vol 88 (5) ◽  
pp. 574-574
Author(s):  
A. P. Malan ◽  
R. Knoetze ◽  
H. J. Hugo

Agathosma betulina, commonly known as buchu, has been used for centuries by the indigenous people of South Africa for medicinal purposes. Currently, the essential oils from buchu are used in medicine, food flavorings, and aromatic oils. Increased exploitation of natural growing buchu in the Fynbos biome and a worldwide shortage of buchu oil encouraged commercial cultivation in South Africa. The root-knot nematode (Meloidogyne spp.) is one of the most common plant-parasitic nematodes found on commercial crops grown in the Western Cape. It has also been isolated from the soil and roots of plants in the natural Fynbos vegetation (2). In June 2003, a nursery propagating buchu plants experienced problems with poor growth. Examination of the buchu roots under a stereo microscope showed extensive galling with large numbers of female root-knot nematodes with eggsacs. Nematode extractions of the soil were also done. Only second-stage juveniles of Meloidogyne spp. (311 per 250 ml of soil) were recovered. A polymerase chain reaction (PCR)-based diagnostic method (1) was used for the identification of the root-knot nematode species. Ten intact females were dissected from the roots and individually placed directly in 5 μl drops of 1× PCR reaction buffer (16 mM [NH4]2SO4, 67 mM tris-HCL, pH 8.8, 0.1% vol/vol Tween 20) ontaining 60 μg/ml of proteinase K. The tube was kept at -80°C for a minimum of 10 min. The tube was incubated at 60°C for 15 min and 5 min at 95°C. The PCR amplifications were then prepared directly in the same tube. Amplified DNA fragments were digested with HinfI and DraI. The digested DNA was loaded on a 2% agarose gel, separated by electrophoresis, and detected by ethidium bromide staining. The digested amplified DNA fragments correspond to those of Meloidogyne javanica. Morphological characteristics were used to verify the PCR-based identification of the nematode. To our knowledge, this is the first report of M. javanica causing extensive galling on the roots of Agathosma betulina. Visual damage to the roots indicates the root-knot nematode to be an important threat to the commercial cultivation of buchu. References: (1) R. Knoetze. Potential of the polymerase chain reaction for the identification of plant-parasitic nematodes. M.Sc. thesis. University of Stellenbosch, Stellenbosch, South Africa, 1999. (2) A. J. Meyer, S. Afr. J. Enol. Vitic., 20:75, 1999.


2021 ◽  
Vol 9 (8) ◽  
pp. 1735
Author(s):  
Juan Wan ◽  
Zebao Dai ◽  
Keqin Zhang ◽  
Guohong Li ◽  
Peiji Zhao

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.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Olaf Kranse ◽  
Helen Beasley ◽  
Sally Adams ◽  
Andre Pires-daSilva ◽  
Christopher Bell ◽  
...  

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.


2007 ◽  
Vol 47 (5) ◽  
pp. 620 ◽  
Author(s):  
B. L. Blair ◽  
G. R. Stirling

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.


EDIS ◽  
2018 ◽  
Vol 2018 (4) ◽  
Author(s):  
Mary Ann D. Maquilan ◽  
Ali Sarkhosh ◽  
Donald W. Dickson

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


Author(s):  
Pranaya Pradhan ◽  
Dhirendra Kumar Nayak ◽  
Manaswini Mahapatra

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.


Nematology ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 87-102 ◽  
Author(s):  
Fouad Mokrini ◽  
Salah-Eddine Laasli ◽  
Youssef Karra ◽  
Aicha El Aissami ◽  
Abdelfattah A. Dababat

Summary Saffron (Crocus sativus) fields in Morocco’s Taliouine and Taznakht regions were surveyed between January and April 2018 to study the diversity and incidence of plant-parasitic nematodes and assess the effects of soil physicochemical properties on the nematodes. Fourteen nematode genera were identified in soil and root samples collected from 66 saffron fields. The most common plant-parasitic nematodes in the Taliouine region were Pratylenchus spp. and Helicotylenchus spp. In the Taznakht region, the most common nematodes were Pratylenchus spp., Tylenchorhynchus spp. and Ditylenchus dipsaci. Nematodes, particularly Pratylenchus spp. and Ditylenchus spp., were abundant and frequent throughout the region. Several nematode genera were significantly associated with soil texture and mineral content, indicating that soil properties play an important role in plant-parasitic nematode communities. This description of plant-parasitic nematode assemblages associated with saffron fields in Morocco and their relationship with soil physicochemical properties provides a starting point from which appropriate nematode management strategies can be implemented.


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