scholarly journals Relative potency of a novel acaricidal compound from Xenorhabdus, a bacterial genus mutualistically associated with entomopathogenic nematodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gamze Incedayi ◽  
Harun Cimen ◽  
Derya Ulug ◽  
Mustapha Touray ◽  
Edna Bode ◽  
...  
Keyword(s):  
Adult Female ◽  
Entomopathogenic Nematodes ◽  
Field Experiments ◽  
Petri Dish ◽  
Phytoseiulus Persimilis ◽  
Mortality Rates ◽  
Predatory Mites ◽  
The Novel ◽  
Compound Identification ◽  
Mutant Strains

AbstractOur study aimed to identify the novel acaricidal compound in Xenorhabdus szentirmaii and X. nematophila using the easyPACId approach (easy Promoter Activated Compound Identification). We determined the (1) effects of cell-free supernatant (CFS) obtained from mutant strains against T. urticae females, (2) CFS of the acaricidal bioactive strain of X. nematophila (pCEP_kan_XNC1_1711) against different biological stages of T. urticae, and females of predatory mites, Phytoseiulus persimilis and Neoseiulus californicus, (3) effects of the extracted acaricidal compound on different biological stages of T. urticae, and (4) cytotoxicity of the active substance. The results showed that xenocoumacin produced by X. nematophila was the bioactive acaricidal compound, whereas the acaricidal compound in X. szentirmaii was not determined. The CFS of X. nematophila (pCEP_kan_XNC1_1711) caused 100, 100, 97.3, and 98.1% mortality on larvae, protonymph, deutonymph and adult female of T. urticae at 7 dpa in petri dish experiments; and significantly reduced T. urticae population in pot experiments. However, the same CFS caused less than 36% mortality on the predatory mites at 7dpa. The mortality rates of extracted acaricidal compound (xenocoumacin) on the larva, protonymph, deutonymph and adult female of T. urticae were 100, 100, 97, 96% at 7 dpa. Cytotoxicity assay showed that IC50 value of xenocoumacin extract was 17.71 μg/ml after 48 h. The data of this study showed that xenocoumacin could potentially be used as bio-acaricide in the control of T. urticae; however, its efficacy in field experiments and its phytotoxicity need to be assessed in future.

The long-term persistence of seeds of oilseed rape (Brassica napus) in arable fields

2003 ◽  
Vol 141 (2) ◽  
pp. 231-240 ◽  
Author(s):  
P. J. W. LUTMAN ◽  
S. E. FREEMAN ◽  
C. PEKRUN
Keyword(s):  
Brassica Napus ◽  
Oilseed Rape ◽  
Field Experiments ◽  
Petri Dish ◽  
Initial Field ◽  
Seed Loss ◽  
Exponential Decline ◽  
Arable Fields ◽  
Decline Curves

The present paper reports on three sets of experiments exploring the persistence of seeds of oilseed rape (Brassica napus). The first, where known numbers of seeds were buried in September 1991 in two field experiments, demonstrated substantial initial losses of seeds, such that only 0·2 and 3·8% of seeds were still present after 4 months. In these experiments, which were not disturbed by mechanical cultivation, there was little evidence of further decline over the following 13 months. In the second of the two experiments, seeds were then left undisturbed for a further 136 months. A mean of 1·8% of seeds were still present after this period, providing further confirmation of the lack of decline in seed numbers in these undisturbed conditions. In the second pair of experiments, known numbers of seeds of three rape cultivars were broadcast onto plots and then either ploughed into the soil immediately after the start of the experiments, or were exposed to weekly shallow tine cultivation followed by ploughing after 4 weeks. The former created a larger seedbank than the latter. The experiments were then ploughed, annually (Expt 1) or at less frequent intervals (Expt 2); appreciable numbers of seeds survived for 65 months in both. Calculations based on exponential decline curves indicated that 95% seed loss would take 15–39 months, depending on the site, cultivar and initial post-harvest stubble treatment. The third part of the paper is based on more detailed studies of persistence of seeds of six cultivars in Petri dishes and buried in 25 cm pots. This work confirmed that cultivars differed in their persistence, as Apex was confirmed as highly persistent, whereas Rebel was short-lived. There were inconsistencies in the response of cultivar Synergy between the Petri-dish and pot experiment, which need further study. This experiment also reinforced the conclusion of the initial field experiments that little seed loss occurs in the absence of cultivations. Appreciable numbers of rape seeds will persist up to 4 years, in normal cropping conditions and in the absence of cultivation one experiment has confirmed persistence for over 11 years.

scholarly journals Activity of insecticides on coffee berry borer (Hypothenemus hampei) (Coleoptera: curculionidae, scolytinae)

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Dieudilait Metellus ◽  
Marcus Vinicius Sampaio ◽  
Fernando Juari Celoto
Keyword(s):  
Field Experiment ◽  
Field Experiments ◽  
Residual Effect ◽  
Petri Dish ◽  
Hypothenemus Hampei ◽  
Artificial Infestation ◽  
Artificial Breeding ◽  
Eggs And Larvae ◽  
Residual Control ◽  
Green Stage

The objective of this work was to evaluate the topical, residual and agronomic effects of the insecticides Voliam Targo, Benevia, Lorsban 480 BR, Curbix 200 SC, Sperto, Verismo, Polytrin 400/40 CE, Curyom 550 EC, Polo 500 SC and Vertimec 18 EC in the control of the berry borer of coffee (H. hampei). The experimental design was completely randomized and four replicates were used in the trials. In the laboratory, a direct spray was sprayed on the insect (topical effect) and applied to the fruits of the coffee (residual contamination). In both experiments, each plot consisted of a Petri dish lined with filter paper, 10 fruits in the green stage and 10 adult females of the berry borer, originating from artificial breeding. Two field experiments were carried out at Campus Glória Experimental Farm. The first one was carried out with the objective of evaluating the residual effect of the insecticides on artificial infestation of the berry borer after applying the products to fruits at the beginning of maturation. The number of perforated fruits, dead females, number of eggs and larvae were evaluated in laboratory and field experiments. The second field experiment had as objective to evaluate the effectiveness in controlling the natural population of the berry borer. Two applications were performed with a 30-day interval, using a motorized turbocharger. The number of fruits bored in 50 fruits per plot and percentage of seeds bored in a sample of 250 seeds per replicate were evaluated. In the laboratory, all insecticides provided mortality higher than 80% in topical application and greater than 73% by residual contamination, except the insecticide Polo 500 SC, which provided a 55% mortality. In the field experiment with artificial infestation, all the insecticides differed from the control, maintaining residual control until 30 days after application and with mortality higher than 70%, reaching up to 100% of mortality. In the test with natural berry borer females infestation the insecticides differed from the control in all evaluated parameters, showed efficacy higher than 75% at 35 days after the second application. The insecticides Voliam Targo, Lorsban 480 BR, Curbix 200 SC, Sperto, Polytrin 400/40 CE and Verismo presented the best control results, being indicated for use in the management of the berry borer of coffee.

scholarly journals Application of Nano Bio-clay Composite in a Scaling-up Study for Wastewater Treatment

2021 ◽  
Vol 12 (5) ◽  
pp. 6393-6414
Keyword(s):  
Industrial Wastewater ◽  
Field Experiments ◽  
Ph Value ◽  
Field Tests ◽  
Scaling Up ◽  
Environmentally Benign ◽  
Impregnation Method ◽  
The Novel ◽  
Wastewater Recycling ◽  
Cr Concentration

A scaling-up study integrating experimental and field experiments was managed to explore the most appropriate catalysis method to assist industries in getting rid of the Congo Red (CR) dye from industrial wastewater. The adsorption potential of kaolinite (K) modified by Ulva Lactuca (UL) was evaluated to eliminate CR dye from aqueous solutions. The novel kaolinite/alga nanocomposite (KUL) was synthesized following steps of the wet impregnation method and then subjected to characterization using different techniques. The newly reported KUL nanocomposite shows a significant increase in adsorption ability higher than that of K and UL. To research different experimental factors' effects, batch experiments were evaluated, and each of the kinetics/isotherms of CR adsorption were explored either. The CR removal% is clearly affected by catalyst dose, working temperature, and pH value with high percentage. The best temperature for CR adsorption onto KUL is 400C at pH>7. CR adsorption on KUL following the first-order diffusion model, while K and UL appeared to follow two different kinetic adsorption models depending on the CR concentration. Moreover, the field tests (scaling-up experiments) revealed optimistic results with 91% efficiency for KUL nano-adsorbents in eliminating mixed dyes from industrial wastewater, which means the foundation of novel environmentally benign nano-adsorbents to help in industrial wastewater recycling.

scholarly journals Novel Keratinolytic Activity of Cyberlindnera fabianii Nrc3 Aza as A Plant Growth Promoting Agent (PGPA)

2015 ◽  
Vol 3 (4) ◽  
pp. 609-618 ◽  
Author(s):  
Azza M. Abdel-fattah ◽  
EL-Shahat H. A. Nashy ◽  
El-Tahir A. Sabiel ◽  
Manal M. Hussien ◽  
Ahmed S. Attia
Keyword(s):  
Plant Growth ◽  
Field Experiments ◽  
The Novel ◽  
Keratinolytic Activity ◽  
Morphological Studies ◽  
Feather Waste ◽  
Plant Growth Promoting ◽  
Growth Promoting ◽  
Keratinase Enzyme

Two field experiments had been conducted in Nubaria sandy soil, Behaira Governate, Egypt to show the effect of keratinase enzyme produced by the novel microbial isolate (Cyberlindnera fabianii NRC3 Aza) on plants.The trials had been conducted in the two successive summer seasons (2011/2012 and 2012/2013) to show the effect of keratinase enzyme from degraded feather–waste on the morphology and chemical composition of peas pods (Pisumsativum L.)–family Fabaceae (Leguminasae). In 2011/2012 season, only the chemical analysis of the dried powdered beads was studied. In 2012/2013 season, the morphological studies of the yield were considered beside the chemical ones. The results depicted significant effects of the sprayed enzyme (keratinase) on peas as plant growth promoting agent (PGPA), compared with the blank (sprayed with water). Electrophoreses and amino acid analysis were carried out for the characterization of the partial pure keratinase enzyme. Int J Appl Sci Biotechnol, Vol 3(4): 609-618

Effects of acaricides on Oligonychus sp. and compatibility with predatory mites Neoseiulus californicus and Phytoseiulus persimilis

2021 ◽  
Author(s):  
Marcos E. Cua-Basulto ◽  
Esaú Ruiz-Sánchez ◽  
Alfonzo Pérez-Gutiérrez ◽  
Rodolfo Martín-Mex ◽  
Ángel Nexticapan-Garcéz ◽  
...  
Keyword(s):  
Phytoseiulus Persimilis ◽  
Predatory Mites ◽  
Neoseiulus Californicus

scholarly journals Analysis of biological parameters of Boophilus microplus Canestrini, 1887 exposed to entomopathogenic nematodes Steinernema carpocapsae Santa Rosa and All strains (Steinernema: Rhabditida)

2005 ◽  
Vol 48 (6) ◽  
pp. 911-919 ◽  
Author(s):  
Gláucia Marques Freitas-Ribeiro ◽  
John Furlong ◽  
Viviane Oliveira Vasconcelos ◽  
Cláudia Dolinski ◽  
Alan Loures-Ribeiro
Keyword(s):  
Entomopathogenic Nematodes ◽  
Petri Dish ◽  
Boophilus Microplus ◽  
Steinernema Carpocapsae ◽  
Survival Period ◽  
Cattle Tick ◽  
Reproductive Efficiency ◽  
Biological Parameters ◽  
Positive Role ◽  
Efficiency Rate

Engorged and partially engorged females of Boophilus microplus were exposed to 600; 3,000; 6,000 and 30,000 infective juveniles of Steinernema carpocapsae Weiser, 1955 Santa Rosa and All strains per dish, under lab conditions. Eggs weight, pre-laying period, laying period, survival period, reproductive efficiency rate, percentage of larval eclosion and lethal concentrations of 50% and 90% (CL50 and CL90) were calculated for engorged females. In the case of partially engorged females, only egg weight, survival period and CL50 and CL90 were calculated. All biological parameters of engorged or partially engorged females were altered by exposition of S. carpocapsae infective juveniles (IJs), Santa Rosa and All strains (p<0.05). The increase in the response was directly proportional to the increase of IJs concentration per Petri dish (p<0.05). Results suggested that entomopathogenic nematodes could have a positive role in the control of cattle tick.

scholarly journals Rapamycin alleviates inflammation and muscle weakness, while altering the Treg/Th17 balance in a rat model of myasthenia gravis

2017 ◽  
Vol 37 (4) ◽  
Author(s):  
Feng Jing ◽  
Fei Yang ◽  
Fang Cui ◽  
Zhaohui Chen ◽  
Li Ling ◽  
...  
Keyword(s):  
T Cells ◽  
Autoimmune Disease ◽  
Myasthenia Gravis ◽  
Rat Model ◽  
Th17 Cells ◽  
Mortality Rates ◽  
The Novel ◽  
Muscular Weakness ◽  
Body Weights ◽  
Experimental Autoimmune

Myasthenia gravis (MG) is an autoimmune disease commonly treated with immunosuppressants. We evaluated the novel immunosuppressant, rapamycin (RAPA), in a rat model of experimental autoimmune MG (EAMG). Mortality rates in the RAPA (12%) were significantly down compared with the EAMG (88%) or cyclophosphamide (CTX) (68%) intervention groups. Muscular weakness decreased after both RAPA and CTX treatment. However, Lennon scores were lower (1.74 ± 0.49, 3.39 ± 0.21, and 3.81 ± 0.22 in RAPA, CTX, and EAMG groups, respectively), and body weights (203.12 ± 4.13 g, 179.23 ± 2.13 g, and 180.13 ± 5.13 g in RAPA, CTX, and EAMG groups, respectively) were significantly higher, only in the RAPA group. The proportion of regulatory T cells (Treg) significantly increased, while that of Th17 cells significantly decreased in the RAPA group compared with the EAMG group. In comparison, CTX intervention resulted in increased Th17 but significantly decreased Tregs. Hence, RAPA can be more effectively used in comparison with CTX to treat MG, with an efficacy higher than that of CTX. In addition, our results suggest RAPA’s efficacy in alleviating symptoms of MG stems from its ability to correct the Treg/Th17 imbalance observed in MG.

Virulence of two entomopathogenic nematode species, Steinernema sp. (strain PQ16) and Heterorhabditis indica (strain KT3987), to nymphs of the coffee cicada Dundubia nagarasingna

Nematology ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Chau N. Nguyen ◽  
Anh T. Do ◽  
Phap Q. Trinh ◽  
Phuc K. Hoang
Keyword(s):  
Biological Control ◽  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Nematode Species ◽  
Mortality Rates ◽  
Coffee Plantations ◽  
Heterorhabditis Indica ◽  
Inoculation Dose ◽  
Pot Trial

Summary The virulence and efficacy of two species of entomopathogenic nematodes, Steinernema sp. (strain PQ16) and Heterorhabditis indica (strain KT3987), against nymphs of the coffee cicada, Dundubia nagarasingna, was evaluated under laboratory and glasshouse conditions. The highest mortality rates of coffee cicada nymphs caused by these two nematode strains were 93.5 and 100%, respectively, at an inoculation dose of 600 infective juveniles (IJ) nymph−1. The virulence (LC50) was established as 137.5 IJ and 149.1 IJ for strains S-PQ16 and H-KT3987, respectively. The highest IJ yields of these nematode strains were 66 × 103 IJ (for S-PQ16) and 134.4 × 103 IJ (for H-KT3987) at a dose of 500 IJ nymph−1. The efficacies of the two nematode strains to coffee cicadas at treated dose of 60 × 103 IJ pot−1 were 84.4 and 88.9% after 30 days, higher than the efficacies at treated dose of 40 × 103 IJ pot−1. The number of IJ in 250 ml of soil at 10, 20 and 30 days after treatment, increased from 0.38 × 103 to 4.80 × 103 IJ in soil treated with a dose of 40 × 103 IJ and from 0.66 × 103 to 5.02 × 103 IJ in soil treated with a dose of 60 × 103 IJ (for S-PQ16). Similarly, for H-KT3987 the number of IJ increased from 0.43 × 103 to 8.99 × 103 IJ and from 0.62 × 103 to 9.64 × 103 IJ, at the respective doses. Based on results of a pot trial from glasshouse modelling, an IJ application dosage for biological control of coffee cicada nymphs in coffee plantations was proposed.

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