scholarly journals Control of root-knot disease of brinjal (Solanum melongena L.) by the application of leaf extracts of certain medicinal plants 

2018 ◽  
Author(s):  
Naseer Hussain Shah ◽  
Abdul Rashid Dar ◽  
Irfana Amin Qureshi ◽  
Afroza Akhter ◽  
Mohammad Rafiq Wani ◽  
...  
Keyword(s):  
Plant Growth ◽  
Meloidogyne Incognita ◽  
Cannabis Sativa ◽  
Solanum Melongena ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Leaf Extracts ◽  
Datura Metel ◽  
Induced Tolerance

Microscopic plant parasitic nematodes are round worms that feed on plants and damage them. The most common and serious amongst the nematodes is the root-knot nematode found throughout the country with a very wide host range of cultivated crops. Brinjal (Solanum melongena) crop yield is considerably reduced by root-knot nematodes particularly Meloidogyne incognita. Root-galls of brinjal caused by Meloidogyne incognita can be controlled effectively by using the bio-agents and botanicals which in turn increases the yield and plant growth. Present study explored the effect of leaf extracts of certain plants on the root-knot development, plant growth and nematode multiplication in pot experiments. Extract treated and nematode inoculated plants showed improvement on growth over untreated inoculated plants and reduced the disease development. Five (viz., margosa, marigold, datura, hemp and tobacco) leaf extracts, irrespective of concentration, apparently induced tolerance in inoculated plants as evidenced by better plant growth in comparison to control and suppressed the multiplication of nematode which resulted in low root-knot index. Margosa (Azadirachta indica) leaf extract suppressed the nematode multiplication, reduced root galling and improved the plant growth of inoculated plants. Margosa and marigold (Tagetes erecta) leaf extracts were found more effective in controlling the root-knot development than the leaf extracts of hemp (Cannabis sativa), datura (Datura metel) and tobacco (Nicotiana tabacum). Higher concentrations (20 ml/plant) of leaf extracts were found to be more effective in controlling the root knot development. Based on our observations, it may be concluded that margosa or marigold extract treatment of brinjal seedlings prior to transplantation can avoid severe damage by suppressing the nematode multiplication and inducing the tolerance in treated inoculated plants.

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

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.

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
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.

Nematicidal activity of the tropane alkaloids hyoscyamine and scopolamine against the root-knot nematode Meloidogyne incognita

Nematology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Djaafar Babaali ◽  
Johannes Roeb ◽  
Sabri Zaidat ◽  
Bouchra Reguige ◽  
Miloud Hammache ◽  
...  
Keyword(s):  
Meloidogyne Incognita ◽  
Tropane Alkaloids ◽  
Datura Stramonium ◽  
Nematicidal Activity ◽  
Crop Damage ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Hyoscyamine And Scopolamine

Summary Alkaloids and alkaloid-producing plants have the potential to reduce crop damage by plant-parasitic nematodes. In a series of in vitro experiments, the nematicidal activity of the tropane alkaloids, hyoscyamine and scopolamine, and a mixture of both on the root-knot nematode, Meloidogyne incognita, was tested. Solutions of 16 mg of compound per ml of solvent were used in concentrations of 80-1280 μg ml−1 of water. Inactivity of second-stage juveniles of M. incognita increased with increasing concentration and exposure time. Lethal concentrations (LC50) after 120 min of exposure ranged from 182.4 μg ml−1 for scopolamine to 318.4 μg ml−1 for hyoscyamine and 332.8 μg ml−1 for the combination of both alkaloids. Similarly, the same concentrations of scopolamine inhibited hatching of M. incognita to a greater extent than hyoscyamine. In a glasshouse experiment, M. incognita was not able to penetrate the roots, induce galls and reproduce on Datura stramonium, D. innoxia and D. tatula. Results indicate that the tropane alkaloids hyoscyamine and scopolamine contained in Datura plants express a strong nematicidal activity against M. incognita and could possibly be used for an alternative and sustainable nematode management.

Responses of Heterodera glycines and Meloidogyne incognita to exogenously applied neuromodulators

2007 ◽  
Vol 81 (4) ◽  
pp. 421-427 ◽  
Author(s):  
E.P. Masler
Keyword(s):  
Meloidogyne Incognita ◽  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Body Movement ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Egg Hatch ◽  
Movement Frequency ◽  
Plant Parasitic

AbstractBiogenic amines regulate important behaviours in nematodes and are associated with pharyngeal activity in plant-parasitic nematodes. A robust behavioural assay based upon nematode body movements was developed to expand the study of these and other neuroregulators in plant-parasitic nematodes. Dopamine, octopamine and serotonin each had significant but differing effects on the behaviour of soybean cyst nematode Heterodera glycines and root-knot nematode Meloidogyne incognita juveniles. Body movement frequency was increased twofold in H.glycines by 5 mM dopamine (P = 0.0001), but decreased by 50 mM dopamine in H. glycines (88%) and M. incognita (53%) (P <  0.0001). Movement frequency in both species was increased by 50–70% (P <  0.0001) by 50 mM octopamine, and 5 mM octopamine increased M. incognita movement frequency more than twofold (P <  0.0001). Movement frequency in each species was reduced by more than 90% by 5 mM serotonin (P <  0.0001). While amplitude of body movement in H. glycines was unaffected by any amine, it was significantly reduced in M.incognita by all amines (P <  0.0006). Stylet pulsing frequencies in either species were unaffected by dopamine or octopamine, but 5 mM serotonin stimulated pulsing in H. glycines by nearly 13-fold (P <  0.0001) and in M. incognita by more than 14-fold (P <  0.0001). The invertebrate neuropeptide FLRFamide (N-Phe-Leu-Arg-Phe) increased M. incognita body movement frequency 45% (P = 0.02) at 1 mM but did not affect stylet activity. Finally, H. glycines egg hatch was completely suppressed by 50 mM serotonin, and partially suppressed by 50 mM dopamine (75%; P <  0.0001) and 50 mM octopamine (55%; P <  0.0001).

scholarly journals Survey of Plant-Parasitic Nematodes Associated with Cotton in Nuh and Palwal Districts of Haryana

2020 ◽  
Vol 7 (1) ◽  
pp. 044-048
Author(s):  
Vinod Kumar ◽  
◽  
Prakash Banakar ◽  
Anil Kumar ◽  
Priyanka Duggal ◽  
...  
Keyword(s):  
Meloidogyne Incognita ◽  
Parasitic Nematodes ◽  
Frequency Of Occurrence ◽  
Density Range ◽  
Plant Parasitic Nematodes ◽  
Rotylenchulus Reniformis ◽  
Root Knot Nematode ◽  
Gossypium Hirsutum L ◽  
Plant Parasitic ◽  
Important Parasite

An extensive survey was conducted to assess the frequency and abundance of plant-parasitic nematodes associated with cotton (Gossypium hirsutum L.) in Haryana (Nuh and Palwal districts) during 2018-20. Based on incidence, population density and associated damage on affected crops, root-knot nematode (Meloidogyne incognita) was considered to be the most important parasite of the crops under local condition. During 2018-19, a total of 11 soil and root samples of cotton were collected from Nuh and Palwal districts. Out of these, eight were found infected with M. incognita with 72.0% frequency of occurrence. The results revealed that out of 7 samples (Nuh), five were found infested with M. incognita with 71.4% frequency of occurrence. In Palwal district, this nematode had 75.0% frequency of occurrence with density range of 60-300 j2 200-1 cc soil. During 2019-20, a total of 27 soil and root samples of cotton were collected from Nuh and Palwal districts. Out of these, 14 were found infected with M. incognita with 51.8% frequency of occurrence. The results revealed that out of 21 samples (Nuh), 12 were found infested with M. incognita with 57.1% frequency of occurrence and density range of 95-690 j2 200-1 cc soil. In Palwal district, this nematode had 33.3% frequency of occurrence (2 out of 6 samples) with density range of 135-435 j2 200-1 cc soil. Other plant parasitic nematodes which were found associated with the cotton belonged to Rotylenchulus reniformis, Hoplolaimus sp., Helicotylenchus sp. and Tylenchorhynchus sp.

scholarly journals Potential of non-fumigant nematicides at different formulations against southern root-knot nematode (Meloidogyne incognita) on tomato plants

2019 ◽  
Vol 8 (1) ◽  
pp. 23-28
Author(s):  
Mohamed S. Khalil ◽  
Abdulqawi A. A. Alqadasi
Keyword(s):  
Meloidogyne Incognita ◽  
Dry Weight ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Tomato Plants ◽  
Shoot Dry Weight ◽  
Soil Population ◽  
Meloidogyne Spp ◽  
Southern Root Knot Nematode

Currently, plant parasitic nematodes (PPN) especially root knot nematodes, Meloidogyne spp. have been found involved in the global losses of tomato crops. The most employed tactic for managing PPN in Africa is non-fumigant nematicides. Recently, in Egypt abamectin was recorded as a new tool to control PPN. Thus, two pot experiments were conducted to evaluate the potential of abamectin and certain non-fumigant nematicides namely; oxamyl and ethoprophos at two different formulations (granular and liquid) against southern root knot nematode (Meloidogyne incognita) on tomato plants under greenhouse conditions. Results revealed the granular formulations of ethoprophos and oxamyl, in addition to abamectin, showed the same significance (P≤0.05) in suppressing tomato soil population and root galls of M. incognita, during both experiments. However, liquid formulations of ethoprophos and oxamyl gave relatively less decreasing in soil population and root galls. On the other hand, all applied treatments improved plant growth criteria ranging from 36.92 to 126.44% in shoot dry weight and from 31.25 to 137.50% in root dry weight for both experiments.

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

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.

Allelopathy: a possible mechanism of suppression of plant-parasitic nematodes by entomopathogenic nematodes

Nematology ◽  
1999 ◽  
Vol 1 (7) ◽  
pp. 735-743 ◽  
Author(s):  
Parwinder S. Grewal ◽  
Edwin E. Lewis ◽  
Sudha Venkatachari
Keyword(s):  
Meloidogyne Incognita ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Steinernema Feltiae ◽  
Symbiotic Bacteria ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Tomato Roots ◽  
Xenorhabdus Nematophilus ◽  
Plant Parasitic

Abstract A possible mechanism of suppression of a plant-parasitic nematode Meloidogyne incognita by entomopathogenic nematodes is described. Heat-killed entomopathogenic nematodes Steinernema feltiae and S. riobrave temporarily suppressed penetration of the root-knot nematode M. incognita into tomato roots, but live nematodes had no effect. Infective juvenile M. incognita were repelled from all entomopathogenic nematode treatments that included their symbiotic bacteria. They were repelled by Galleria mellonella cadavers infected with S. carpocapsae, S. feltiae, and S. riobrave and from cell-free culture filtrates of the symbiotic bacteria Xenorhabdus nematophilus, X. bovienii, and Xenorhabdus sp. "R" from the three nematode species, respectively. Cell-free filtrates from all three Xenorhabdus spp. were toxic to M. incognita infective juveniles causing 98-100% mortality at 15% concentration. Cell-free filtrate of Xenorhabdus sp. "R" also reduced the hatch of M. incognita eggs. Application of formulated bacterial cell-free filtrates temporarily suppressed M. incognita penetration into tomato roots in a greenhouse trial. The short-term effects of cell-free bacterial filtrates, namely toxicity and repellency, were almost entirely due to ammonium. These results demonstrate allelopathic interactions between plant-parasitic nematodes, entomopathogenic nematodes and their symbiotic bacteria. The likely role of allelopathy in the suppression of plant-parasitic nematodes by innundative applications of entomopathogenic nematodes is discussed. Allelopathie: Ein moglicher Mechanismus zur Unterdruckung pflanzenparasitarer Nematoden durch insektenpathogene Nematoden - Es wird ein moglicher Mechanismus zur Unterdruckung des pflanzenparasitaren Nematoden Meloidogyne incognita durch insektenpathogene Nematoden beschrieben. Durch Hitze abgetotete insektenpathogene Nematoden Steinernema feltiae und S. riobrave underdruckten das Eindringen des Wurzelgallenalchens M. incognita in Tomatenwurzeln, lebende Nematoden hatten keine Wirkung. Infektionsjuvenile von M. incognita wurden von allen Behandlungen mit insektenpathogenen Nematoden abgestossen, die auch die symbiontischen Bakterien einschlossen. Sie wurden durch die Kadaver von Galleria mellonella abgestossen, die mit S. carpocapsae, S. feltiae und S. riobrave infiziert waren sowie durch zellfreie Kultursubstrate der symbiontischen Bakterien Xenorhabdus nematophilus, X. bovienii und Xenorhabdus sp. "R" aus den drei genannten Nematodenarten. Zellfreie Kultursubstrate von allen drei Xenorhabdus spp. waren giftig fur die Infektionsjuvenilen von M. incognita und verursachten in einer Konzentration von 15% Abtotungsraten von 98-100%. Zellfreie Kultursubstrate von Xenorhabdus sp. "R" vermiderten ausserdem das Schlupfen von M. incognita-Eiern. In einem Gewachshausversuch unterdruckten formulierte zellfreie Bakterienfiltrate vorubergehend das Eindringen von M. incognita in Tomatenwurzeln. Die Kurzzeitwirkungen von zellfreien Bakterien filtraten, namentlich Giftigkeit und Abstossung, waren nahezu ganz bedingt durch Ammoniak. Diese Ergebnisse zeigen das Vorhandensein von allelopathischen Wechselwirkungen zwischen pflanzenparasitaren Nematoden, insektenpathogenen Nematoden und deren symbiontischen Bakterien. Die wahrscheinliche Rolle von Allelopathie bei der Unterdruckung pflanzenparasitarer Nematoden durch eine Massenanwendung insektenpathogener Nematoden wird diskutiert.

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

2007 ◽  
Vol 47 (5) ◽  
pp. 620 ◽  
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.

Host suitability of summer cover crops to Meloidogyne arenaria, M. enterolobii, M. incognita and M. javanica

Nematology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Hung X. Bui ◽  
Johan A. Desaeger
Keyword(s):  
Cover Crops ◽  
Nematode Species ◽  
Host Suitability ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Sunn Hemp ◽  
Host Status ◽  
Susceptible Control ◽  
Sorghum Sudangrass

Summary Cover crops can be a useful tool for managing plant-parasitic nematodes provided they are poor or non-hosts for the target nematode species. A glasshouse experiment was done to determine the host status of four common cover crops in Florida, sunn hemp, cowpea, sorghum sudangrass and sunflower, to pure populations of four common tropical root-knot nematode (RKN) species Meloidogyne javanica (Mj), M. incognita (Mi), M. enterolobii (Me) and M. arenaria (Ma). Tomato was included as a susceptible control. Eight weeks after nematode inoculation (WAI), tomato showed the highest root gall damage for all tested RKN species, with gall indices (GI) between 7 (Ma) and 8.5 (Me) and reproduction factor (RF) ranging from 20 (Ma) to 50 (Mj). No visible root galls were observed for any of the RKN species on sunn hemp and sorghum sudangrass at 8 WAI. However, Mj and Mi were able to reproduce slightly on sorghum sudangrass (RF = 0.02 and 0.79, respectively). Sunflower and cowpea were infected by all four tested RKN species, but host suitability varied. Sunflower root galling ranged from 1.1 (Me) to 4.5 (Mj) and RF = 3.2 (Me) to 28.7 (Mj), while cowpea root galling ranged from 0.6 (Mi) to 5.1 (Me) and RF = 0.8 (Mi) to 67.3 (Mj). Sunn hemp and, to a lesser extent, sorghum sudangrass were poor hosts to all four tested RKN species. Sunflower was a good host to all RKN species, but root gall damage and RF were lowest for Me. Cowpea was a good host to Mj, Me and Ma, but a poor host to Mi. Our results confirm and stress the importance of RKN species identification when selecting cover crops as an RKN management strategy.

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