scholarly journals Nematicidal activity of native Bacillus thuringiensis against the root knot nematode, Meloidogyne incognita (Kofoid and White)

2020 ◽  
Vol 30 (1) ◽  
Author(s):  
A. Ramalakshmi ◽  
R. Sharmila ◽  
M. Iniyakumar ◽  
V. Gomathi
Nematology ◽  
2013 ◽  
Vol 15 (5) ◽  
pp. 545-555 ◽  
Author(s):  
Yong Seong Lee ◽  
Muhammad Anees ◽  
Hae Nam Hyun ◽  
Kil Yong Kim

Lysobacter antibioticus HS124 is an antagonistic bacterial strain that was previously isolated from the rhizosphere soil of pepper and showed an enhanced ability to produce lytic enzymes as well as an antibiotic that was identified as 4-hydroxyphenylacetic acid (4-HPAA). In the present study, nematicidal activity of the strain and 4-HPAA against the root-knot nematode, Meloidogyne incognita, causing disease in tomato was investigated in both in vitro and in vivo conditions. For this purpose, adding different concentrations of culture filtrate, crude extract collected from extraction with ethyl acetate and 4-HPAA, in 24-well plates containing ca 500 eggs or 300 second-stage juveniles (J2), significantly decreased the rate of nematode hatch and caused higher mortality of J2 compared with the control treatments. Nematicidal activity of the bacterial strain was further confirmed by conducting pot experiments in which tomato plants were inoculated with M. incognita and the HS124 culture (BC). The control pots were treated with commercial nematicide (CN, 5% Ethoprophos), tap water (TW) or the non-inoculated bacterial culture medium (BCM). In these pot experiments, results demonstrated a strong antagonistic potential of L. antibioticus HS124 against M. incognita where the disease was significantly reduced in the pots treated with BC as compared to TW or BCM. Furthermore, the shoot fresh weight was also increased significantly, which may be attributed to the disease control ability of the strain. Hence, L. antibioticus HS124 may be further developed as a potential biocontrol of root knot nematode in the field.


Author(s):  
José Alonso Calvo- Araya ◽  
Nery Zapata- Montes

The evaluation of nematicidal activity of the non- fumigant nematicide (fluensulfone) was evaluated for the control of the root-knot nematode Meloidogyne incognita in bell pepper crop (Capsicum annuum L.) under field conditions. The experiment was set up under a randomized complete block design with four replications. Six treatments were assessed for control of M. incognita: four doses of fluensulfone, one of the nematicide oxamyl and a control without application of nematicides. Ten days before transplanting, nematicides were applied in a single application via irrigation systems. The lowest final population densities of M. incognita in bell pepper crop were recorded in plots treated with fluensulfone at the dose of 2.75 L.ha-1, with an average of 25 juveniles. The higher percentage of efficacy was obtained with the application of fluensulfone at a dose of 2.75 L.ha-1. Fluensulfone showed a more efficient nematicidal activity as compared with oxamyl, which is the most used nematicide in horticultural crops in Mexico. Our results indicated that fluensulfone can be used as an alternative nematicide for the control of M. incognita in horticultural crops.


2012 ◽  
Vol 48 (No. 4) ◽  
pp. 170-178 ◽  
Author(s):  
M.S. Khalil ◽  
M.E.I. Badawy

The nematicidal activity of four molecular weights (2.27 &times; 10<sup>5</sup>, 3.60 &times; 10<sup>5</sup>, 5.97 &times; 10<sup>5</sup>, and 9.47 &times; 10<sup>5</sup> g/mol) of a biopolymer chitosan was assayed against the root-knot nematode, Meloidogyne incognita, in vitro and in pot experiments. In laboratory assays, the nematode mortality was significantly influenced by exposure times and chitosan molecular weight. Low molecular weight chitosan (2.27 &times; 10<sup>5</sup> g/mol) was the most effective in killing the nematode with EC<sub>50</sub> of 283.47 and 124.90 mg/l after 24 and 48 h of treatment, respectively. In a greenhouse bioassay, all the compounds mixed in soil at one- and five-fold concentrations of the LC<sub>50</sub> value significantly reduced population, egg mass, and root galling of tomato seedlings compared with the untreated control. In general, the nematicidal activity of these compounds was increased dramatically with a decrease in the molecular weight. The results suggest that the chitosan at low molecular weight may serve as a natural nematicide


2013 ◽  
Vol 68 (7-8) ◽  
pp. 307-312 ◽  
Author(s):  
Peng Hua Bai ◽  
Chun Qi Bai ◽  
Qi Zhi Liu ◽  
Shu Shan Du ◽  
Zhi Long Liu

Hydrodistilled essential oil from Rhododendron anthopogonoides Maxim. (Ericaceae) aerial parts was analysed by gas chromatography-mass spectrometry (GC-MS). A total of 42 compounds, accounting for 95.48% of the total oil, were identified. The main constituents of the essential oil were benzyl acetone (34.41%), nerolidol (10.19%), 1,4-cineole (8.41%), β-caryophyllene (5.63%), γ-elemene (5.10%), and spathulenol (3.06%). Four constituents were isolated from the essential oil based on fractionation. The essential oil of R. anthopogonoides possessed nematicidal activity against the root knot nematode (Meloidogyne incognita) with an LC50 value of 130.11 μg/ml. The main compound of the essential oil, benzyl acetone, exhibited nematicidal activity against M. incognita with an LC50 value of 74.17 μg/ ml while 1,4-cineole, nerolidol, and β-caryophyllene were not nematicidal at a concentration of 5 mg/ml. The essential oil of R. anthopogonoides and benzyl acetone show potential for their development as possible natural nematicides for the control of the root knot nematode


2020 ◽  
Vol 76 (6) ◽  
pp. 2217-2224 ◽  
Author(s):  
Guangying Liu ◽  
Xu Lin ◽  
Shuangyu Xu ◽  
Guang Liu ◽  
Feng Liu ◽  
...  

2010 ◽  
Vol 100 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Sergio Echeverrigaray ◽  
Jucimar Zacaria ◽  
Ricardo Beltrão

Nematicidal activity of 22 monoterpenoids were evaluated in vitro and in pot experiments. Twenty of the twenty-two monoterpenoids significantly reduced hatching, and 11 reduced J2 mobility of the root-knot nematode Meloidogyne incognita at a concentration of 250 mg/liter. In general, compounds with hydroxyl and carbonyl groups exhibited higher nematicidal activity than other terpenoids. Borneol, carveol, citral, geraniol, and α-terpineol showed the highest nematicidal activity among the in vitro tested monoterpenoids. These compounds exhibited a dose dependent effect, and drastically reduced eggs hatching and J2 viability at low concentrations. These monoterpenoids, at 100 and 250 mg/kg concentration, diminished root galling of tomato plants in pot experiments. The results suggest that the selected monoterpenoids, and essential oils with high concentration of these compounds, are potential nematicides against Meloidogyne.


2013 ◽  
Vol 61 (41) ◽  
pp. 9784-9788 ◽  
Author(s):  
Pierluigi Caboni ◽  
Marco Saba ◽  
Graziella Tocco ◽  
Laura Casu ◽  
Antonio Murgia ◽  
...  

Nematology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Djaafar Babaali ◽  
Johannes Roeb ◽  
Sabri Zaidat ◽  
Bouchra Reguige ◽  
Miloud Hammache ◽  
...  

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.


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