scholarly journals Paecilomyces formosus MD12, a Biocontrol Agent to Treat Meloidogyne incognita on Brinjal in Green House

2021 ◽  
Vol 7 (8) ◽  
pp. 632
Author(s):  
Alaa Baazeem ◽  
Mohammed Alorabi ◽  
Palanisamy Manikandan ◽  
Saqer S. Alotaibi ◽  
Abdulaziz Almanea ◽  
...  

The present study was carried out to analyze the potential of fungi isolated from the rhizosphere of soybean, brinjal, tomato, and potato plants. The density of fungi varied in the pot soil and rhizosphere after Paecilomyces formosus MD12 treatment. The P. formosus MD12 population was 6.3 ± 0.13 × 104 CFU g−1 in the pot planted with brinjal, and the population increased in the rhizosphere (6.72 ± 0.41 × 104 CFU g−1). P. formosus MD12 was cultured in the production medium, and the supernatant was used for egg inhibition studies on a root-knot nematode parasite, Meloidogyne incognita. It was revealed that maximum egg inhibition (94.7 ± 6.2%) was obtained at 100% concentration of extract. The culture supernatant from P. formosus MD12 affected the development of M. incognita juvenile, and the mortality rate was maximum after 96 h (95 ± 6%). Mortality was reduced when treated with 25%, 50%, and 75% supernatant. At 1 × 107 mL−1 of spore suspension, we found reductions of 71.6 ± 3.3% nematode populations in the soil, 60.7 ± 2.2% from the root, and 63.6 ± 2.4% egg mass compared with the control in the pot experiment. The culture supernatant applied at the 10% level showed a maximum mean reduction of the nematode population in roots (72.4 ± 2.2%), soil (77.9 ± 2.5%), and egg masses (73.2 ± 1.5%), respectively. The presence of P. formosus MD12 in a soil environment could antagonize nematode parasites and improve soil amendment. The P. formosus MD12 strain showed good biocontrol ability against the root-knot nematode, M. incognita, under in vitro and green house experimental condition.

2019 ◽  
Vol 12 (1) ◽  
pp. 24-37
Author(s):  
M.A. Radwan ◽  
A.S.A. Saad ◽  
H.A. Mesbah ◽  
H.S. Ibrahim ◽  
M.S. Khalil

Summary Avermectins and spinosyns are structurally related natural products of microbial origin and belong to a new family of macrolides which are active against a vast array of invertebrate pests. In the present study, the effects of four members of macrolides; abamectin (ABM), emamectin benzoate (EMB), spinosad (SPI) and spinetoram (SPIT), on Meloidogyne incognita were investigated under in vitro and in vivo conditions. All compounds reduced egg hatching and led to high mortality of the nematode second-stage juveniles (J2). ABM showed the maximum rate of egg hatching inhibition and J2 mortality while SPIT recorded the minimum. All treatments reduced the number of galls, egg masses, eggs/egg mass in roots and J2 in the soil when compared to the control. Based on the 10 folds of the 24 h-LC50 values of J2 mortality in vitro, EMB and ABM exhibited higher percent reduction in galls (79.68 and 71.45%), egg masses (75.19 and 70.54%), eggs/egg mass (60.49 and 40.91%) and J2 in the soil (90.31 and 86.54%), respectively, compared to SPI and SPIT. Significant increase in tomato shoot height occurred in all biopesticides (10 folds) and SPIT (20 folds). SPI at 10 folds of the 24 h-LC50 values of J2 mortality in vitro, significantly increased root length while ABM at 50 folds and SPIT at 20 folds decreased root length by 5.15% and 5.88%, respectively, compared to the untreated inoculated plants. In all treatments, the dry shoot and root weights increased, compared to the untreated control. Our findings suggest that these macrolides have the ability to regulate nematode population densities and may be an alternative to classical nematicides.


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


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Zubair Rehman Nengroo ◽  
Zeshan Umer Shah ◽  
Adil Shafi Ganie ◽  
Mohammad Danish

AbstractThe current study was assumed to identify the novel nematicidal activity of chloroform and methanol (50:50, v/v) seed extracts of eight medicinally important plants viz. Abrus precatorius Linn., Amaranthus virdis Linn., Bunium persicum Boiss., Dioscorea deltoidea Wall. Ex Griseb., Teraxacum officinale Weber., Malva neglecta Wall., Podophylum hexandrum Royle and Robina pseudoacacia Linn. using the root-knot nematode Meloidogyne incognita in in vitro and greenhouse experiments. At 72 h exposure, the extracts were found to be highly nematostatic, where nematodes were completely paralyzed at 12 and 48 h of exposure. However, dominant mortality was observed by T. officinale 93.67% and B. persicum 89.66% seed extracts at 72 h. In greenhouse method, extracts of T. officinale and B. persicum extracts were found to be most potent in reducing number of galls (1.76 and 2.37) and number of egg masses (0.06 and 2.18) respectively as compared to inoculated control. The root knot index of all extracts varied between 1–3 and egg mass index 0–3 as compared to control. This study suggested that seed extracts of these plants can be used for the management of M. incognita and could be used in replacement of synthetic nematicides upon further isolation and purification of bioactive substance responsible for nematicidal activity.


2017 ◽  
Vol 4 (3) ◽  
pp. 1-7 ◽  
Author(s):  
Amir Khan ◽  
Moh Tariq ◽  
Mohd Asif ◽  
Mansoor Siddiqui

Author(s):  
Refik Bozbuga ◽  
H. Yildiz Dasgan ◽  
Yelderem Akhoundnejad ◽  
Mustafa Imren ◽  
Halil Toktay ◽  
...  

Root knot nematodes (<italic>Meloidogyne</italic> spp.) cause immense yield losses in crops throughout the world. Use of resistant germplasms of plants limits the root knot nematode damages. In this study, 87 common bean (<italic>Phaseoulus vulgaris</italic> L.) genotypes were screened against the root knot nematode, <italic>Meloidogyne incognita</italic> to determine the resistance response under growth chamber conditions in Turkey. <italic>P. vulgaris</italic> genotypes were evaluated based on resistance index (RI); root galling severity and nematode egg mass production on a 1-9 scale. The nematode negatively influenced the growth (fresh weight) of bean genotypes. At the completion of the study, 13 bean genotypes were found as immune (Sehirali), highly resistant (TR42164, Seleksiyon 5, Seker Fasulye, Fas-Agadir-Suk-1) and moderately resistant (Acik Badem, TR68587, TR43477, TR53827, TR28018, Gülnar-3, Siyah Fasulye, Kibris Amerikan) against <italic>M. incognita</italic> thus suggesting the use of such genotypes in breeding studies as a parental material to develop the root knot nematode resistant cultivars.


Nematology ◽  
2007 ◽  
Vol 9 (3) ◽  
pp. 343-349 ◽  
Author(s):  
Michael Boppré ◽  
Tim Thoden ◽  
Johannes Hallmann

Abstract1,2-dehydropyrrolizidine alkaloids (PAs) represent a class of secondary plant compounds that are active in defence against herbivory. They are present in Chromolaena odorata, one of the most invasive weeds of Asia and Africa. In vitro studies demonstrate that pure PAs from C. odorata roots have nematicidal effects on the root-knot nematode Meloidogyne incognita, even at concentrations of 70-350 ppm. In vivo experiments show that mulch or aqueous crude extracts from C. odorata roots reduce the infection of lettuce by M. incognita. Thus, the use of PA-containing plants appears to be a valuable element for integrated nematode management.


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.


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