scholarly journals Antifungal Effects of Paraquat and Glyphosate on Rhizoctonia solani (Kühn) in Potato in vitro Condition

2021 ◽  
Vol 10 (1) ◽  
pp. 16
Author(s):  
José L. Arispe Vázquez ◽  
Abiel Sánchez Arizpe ◽  
Ma E. Galindo Cepeda ◽  
Cristina Trejo Ramos

Potato is one of the main crops worldwide. It this research, antifungal activity in vitro of paraquat and glyphosate were evaluated for Rhizoctonia solani control. R. solani was identified from potato tubers collected out from at open markets in Saltillo, Coahuila, Mexico. Two types of herbicides were applied: paraquat and glyphosate, at four different dosage treatments of: 10, 100, 1 000 and 10 000 μL. One 5 mm diameter PDA disc with R. solani mycelium was placed at the center of the Petri dish, with a radial registry fungal every 24 h for 192 h. Pathogen was identified by morphological criteria and the data was evaluated randomly with a factorial arrangement, on which, herbicides represented factor A and dosage treatments were represented by factor B. Thus experimental design had two levels for factor A and five levels for factor B with six replications. The results were analyzed by the SAS version 9.1 statistical program, the mean separation with the Tukey test (p=0.05). Glyphosate achieved inhibition of R. solani by 35.5882% and paraquat up to 80.0399%. Results reveal the importance of the need for more studies of these herbicides as fungicides. High concentrations of paraquat (10 000 μL) inhibits R. solani, and glyphosate does not affect R. solani mycelium development at low dosages (10 and 100 μL) and inhibits it at higher doses (10 000 μL).

Plant Disease ◽  
2016 ◽  
Vol 100 (12) ◽  
pp. 2427-2433 ◽  
Author(s):  
Sahar Arabiat ◽  
Mohamed F. R. Khan

Rhizoctonia damping-off and crown and root rot caused by Rhizoctonia solani are major diseases of sugar beet (Beta vulgaris L.) worldwide, and growers in the United States rely on fungicides for disease management. Sensitivity of R. solani to fungicides was evaluated in vitro using a mycelial radial growth assay and by evaluating disease severity on R. solani AG 2-2 inoculated plants treated with fungicides in the greenhouse. The mean concentration that caused 50% mycelial growth inhibition (EC50) values for baseline isolates (collected before the fungicides were registered for sugar beet) were 49.7, 97.1, 0.3, 0.2, and 0.9 μg ml−1 and for nonbaseline isolates (collected after registration and use of fungicides) were 296.1, 341.7, 0.9, 0.2, and 0.6 μg ml−1 for azoxystrobin, trifloxystrobin, pyraclostrobin, penthiopyrad, and prothioconazole, respectively. The mean EC50 values of azoxystrobin, trifloxystrobin, and pyraclostrobin significantly increased in the nonbaseline isolates compared with baseline isolates, with a resistant factor of 6.0, 3.5, and 3.0, respectively. Frequency of isolates with EC50 values >10 μg ml−1 for azoxystrobin and trifloxystrobin increased from 25% in baseline isolates to 80% in nonbaseline isolates. Although sensitivity of nonbaseline isolates of R. solani to quinone outside inhibitors decreased, these fungicides at labeled rates were still effective at controlling the pathogen under greenhouse conditions.


Blood ◽  
1971 ◽  
Vol 37 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Y. YOSHIDA ◽  
D. G. OSMOND

Abstract Radioautography with 3H-thymidine was used to examine the proliferative activity of bone marrow lymphoid cells and to identify the precursor cells of small lymphocytes in short-term cultures of lymphocyte-rich marrow fractions. High concentrations of small lymphocytes (nuclear diameters less than 8.0 µ in smears) together with large lymphoid ("transitional") cells (nuclear diameters greater than 8.0 µ) were separated from suspensions of guinea pig bone marrow by centrifugation in linear sucrose-serum density gradients. When such lymphocyte-rich marrow fractions were cultured in vitro the labeling and mitotic indices following either continuous or terminal exposure to 3H-thymidine indicated that the large lymphoid cells were confined mainly to the pre-DNA-synthetic (G1) and early DNA-synthetic (S) phases at first, but proceeded subsequently through S phase and mitosis. From these data tentative values were derived for the in vitro duration of G1 (12 hours) and S (13.7 hours). Further cultures were followed radioautographically after a 1-hour pulse of 3H-thymidine at 6-7 hours of culture. The absolute numbers of labeled large lymphoid cells declined during the subsequent 21 hours but, simultaneously, labeled small lymphocytes appeared and increased progressively in absolute numbers to 44.4 ± 8.1 per cent of the initial numbers of labeled large lymphoid cells. The mean grain count of labeled small lymphocytes was half that of the initially labeled large lymphoid cells. Very few labeled undifferentiated cells other than large lymphoid cells were observed. The results demonstrate that lymphocyte-rich marrow fractions are capable of sustaining the production of small lymphocytes in short-term cultures and that the immediate precursors of marrow small lymphocytes are contained within a population of large lymphoid cells.


2001 ◽  
Vol 9 (4) ◽  
pp. 239-244 ◽  
Author(s):  
Alla Aroutcheva ◽  
Jose A. Simoes ◽  
Susan Shott ◽  
Sebastian Faro

Objective:To evaluate thein vitroeffect of varying concentrations of clindamycin onLactobacillusspp.Methods: Concentrations of clindamycin ranging from 1.95–20 000 mg/ml were studied for their effect on the growth of six strains ofLactobacillus.Results:Clindamycin concentrations between 1.95–31.25 mg/ml had no statistically significant effect on growth of lactobacilli (p> 0.05). Concentrations 125 and 250 mg/ml had a bacteriostatic effect. The mean minimum inhibitory concentration (MIC) for studiedLactobacillusstrains was determined as 1000 mg/ml.Conclusion:High concentrations of clindamycin achieved in the vagina by intravaginal application might be inhibitory forLactobacillus.


Reproduction ◽  
2000 ◽  
pp. 151-158 ◽  
Author(s):  
MA Driancourt ◽  
J Fevre ◽  
J Martal ◽  
KH Al-Gubory

Ovarian follicular growth and maturation and its control throughout pregnancy have not been described fully in sheep. Experiment 1 characterized the size and maturation (steroid production in vitro and aromatase activity) of ovarian follicles obtained at days 20, 50, 80 and 110 of pregnancy compared with those obtained at day 12 of the oestrous cycle. There was no difference in the number of small follicles (< 3 mm in diameter) between cyclic and pregnant ewes, regardless of the stage of pregnancy. There was a marked reduction (P < 0.01) in the number of medium follicles (3-5 mm) starting at day 80 of pregnancy. Large follicles (> 5 mm) were not detected at day 110 of pregnancy. In vitro testosterone output by follicles was constant throughout pregnancy. Oestradiol output remained steady until day 80, but decreased markedly at day 110 of pregnancy. This decrease was associated with a reduction in aromatase activity in follicles obtained at this stage. Experiment 2 examined the effect of administration of high concentrations of progesterone between day 100 and day 120 after mating on resumption of follicular growth in ewes that underwent Caesarean section at day 99 of pregnancy. In ewes that underwent Caesarean section, progesterone supplementation was successful in mimicking the profile found in pregnant ewes, but did not prevent re-initiation of follicular growth, as demonstrated by the presence of large follicles (> 5 mm) at day 120 after mating. Experiment 3 examined the effects of PGF(2alpha)-induced regression of the corpus luteum of day 100 of pregnancy on resumption of follicular growth. High concentrations of PGF(2alpha) (0.28 mg kg(-1) body weight) administrated at day 100 of pregnancy were required to initiate regression of the corpus luteum. At day 120 after mating, the mean (+/- SEM) diameter of the largest follicle in PGF(2alpha)-treated ewes (3.40 +/- 0.47 mm) was significantly greater (P < 0.05) than that in control pregnant ewes (2.52 +/- 0.34 mm). Experiment 4 examined the effect of removal of the fetus and of the corpus luteum at day 100 of pregnancy on resumption of ovulation. Removal of the corpus luteum by PGF(2alpha) treatment at the time of removal of the fetus resulted in earlier occurrence of short luteal phases (27.8 versus 40.6 days, PGF(2alpha)-treated versus non-treated) but did not alter the timing of the first normal luteal phases (41 days). In conclusion, the results from these experiments indicate that placental compounds play a major role in inhibiting follicular growth and maturation during late pregnancy in sheep.


1958 ◽  
Vol 41 (5) ◽  
pp. 879-900 ◽  
Author(s):  
William G. Van der Kloot

Isolated frog sartorii were exposed for 30 minutes to HETP—an irreversible anti-cholinesterase, and were then soaked in Ringer's at 15°C. for 16 hours. At the end of the period of soaking the mean resting potential of the muscle fibers was only 29 mv. The decrease in the resting potential of the HETP-treated muscles was accompanied by a loss of potassium and a gain in sodium by the muscles. The effect of anticholinesterases on sodium extrusion was studied by incubating the muscles in a Ringer's containing half of the normal amount of sodium. The muscles respond by extruding sodium against a concentration gradient into the external medium. Sodium extrusion was blocked by prior exposure of the muscle to HETP, and reversibly blocked by exposure to physostigmine. The inhibition of sodium extrusion by physostigmine was correlated with the inhibition of the intracellular cholinesterase. Sodium extrusion was also blocked by high concentrations of 2-methyl-1,4-napthaquinone 8-sulfonic acid and by α-ketoglutarate, which are known to inhibit choline acetylase in vitro. But sodium extrusion was not affected by a third inhibitor of choline acetylase, phenobarbital. Sodium extrusion was unaffected by KCN and partially blocked by IAA. The IAA block was eliminated by the addition of pyruvate. It is concluded that either glycolysis or oxidative metabolism can furnish the energy needed for sodium extrusion.


2006 ◽  
Vol 50 (6) ◽  
pp. 1927-1930 ◽  
Author(s):  
Kesinee Chotivanich ◽  
Jetsumon Sattabongkot ◽  
Rachanee Udomsangpetch ◽  
Sornchai Looareesuwan ◽  
Nicholas P. J. Day ◽  
...  

ABSTRACT The infectivity of Plasmodium falciparum gametocytes after exposure in vitro to quinine, artesunate, and primaquine was assessed in Anopheles dirus, a major vector of malaria in Southeast Asia. Mature gametocytes (stage 5) of a Thai isolate of P. falciparum were exposed to the drugs for 24 h in vitro before membrane feeding to A. dirus. After 10 days, the mosquito midguts were dissected and the oocysts were counted. In this system, artesunate showed the most potent transmission-blocking activity; the mean (standard deviation [SD]) 50% and 90% effective concentrations (EC50, and EC90, respectively, in nanograms per milliliter) were 0.1 (0.02) and 0.4 (0.15), respectively. Transmission-blocking activity of quinine and primaquine was observed at relatively high concentrations (SDs): EC50 of quinine, 642 (111) ng/ml; EC50 of primaquine, 181 (23) ng/ml; EC90 of quinine, 816 (96) ng/ml; EC90 of primaquine, 543 (43) ng/ml. Artesunate both prevents the maturation of immature P. falciparum gametocytes and reduces the transmission potential of mature gametocytes. Both of these effects may contribute to reducing malaria transmission.


2019 ◽  
Vol 29 ◽  
pp. 1-11
Author(s):  
Luis Roberto Pérez Moreno ◽  
Luis Pérez-Moreno ◽  
Rafael Guzmán-Mendoza ◽  
Diana Sanzón-Gómez ◽  
José Roberto Belmonte-Vargas

Se evaluó la respuesta in vitro de un aislado de los hongos Alternaria sp., Fusarium sp., Rhizoctonia solani, a 16 agentes biológicos (AB), ocho fungicidas y un testigo. Se usó un diseño experimental completamente al azar con arreglo factorial. El factor A correspondió a los aislados del hongo y el factor B a los productos de control. La comparación de medias se realizó con la prueba de Tukey (p < 0.05). Se hizo la evaluación del crecimiento promedio radial micelial en centímetros (Cprm) cada 24 h durante 11 días. En cualquier caso, no se encontró efecto, solo o en interacción con los agentes de control. Dicloran, Tebuconazol y Cyprodinil-Fludioxonil inhibieron el crecimiento micelial de todos los aislados de los hongos con un promedio final de 1.0 Cprm, y en mayor proporción que los agentes biológicos. Los AB que propiciaron el menor crecimiento micelial de los aislados fueron: Trichoderma sp., Trichoderma harzianum, Microorganismos y Trichoderma viridae.


2005 ◽  
Vol 494 ◽  
pp. 549-554 ◽  
Author(s):  
S. Trajković ◽  
S. Dobrić ◽  
A. Djordjević ◽  
V. Dragojević-Simić ◽  
Z. Milovanović

In vitro studies have demonstrated that fullerenol, a polyhydroxylated derivative of fullerene (C60(OH)n n = 12-26), has a high antioxidative potential. Since any radiation injury is mainly a consequence of the action of free radical species, the aim of this study was to examine radioprotective efficiency of fullerenol in whole-body irradiated mice. The experiment was performed on male, adult, white mice, whole-body irradiated with Xrays doses of 6 to 8 Gy (X-ray energy of 8 MV). Fullerenol C60(OH)24 was given in doses of 10 and 100 mg/kg i.p. 30 minutes before irradiation. The experimental groups consisted of 25-30 animals each. The survival rate and body mass gain of irradiated animals were monitored for 30 days after irradiation. The mean lethal times (LT50) of irradiated mice and mean lethal dose of X-rays were calculated and compared. The results showed that fullerenol C60(OH)24, in a dose of 100 mg/kg i.p., prolonged LT50 of irradiated mice. This effect was especially pronounced in mice irradiated with 7 and 8 Gy of X-rays. It seems that radioprotective efficiency of fullerenol C60(OH)24 is more marked in mice irradiated by higher doses of X-rays.


2021 ◽  
Vol 22 (21) ◽  
pp. 12002
Author(s):  
Silja Skogstad Tuv ◽  
Marianne Skov-Skov Bergh ◽  
Jannike Mørch Andersen ◽  
Synne Steinsland ◽  
Vigdis Vindenes ◽  
...  

Methiopropamine is a novel psychoactive substance (NPS) that is associated with several cases of clinical toxicity, yet little information is available regarding its neuropharmacological properties. Here, we employed in vitro and in vivo methods to compare the pharmacokinetics and neurobiological effects of methiopropamine and its structural analog methamphetamine. Methiopropamine was rapidly distributed to the blood and brain after injection in C57BL/6 mice, with a pharmacokinetic profile similar to that of methamphetamine. Methiopropamine induced psychomotor activity, but higher doses were needed (Emax 12.5 mg/kg; i.p.) compared to methamphetamine (Emax 3.75 mg/kg; i.p.). A steep increase in locomotor activity was seen after a modest increase in the methiopropamine dose from 10 to 12.5 mg/kg, suggesting that a small increase in dosage may engender unexpectedly strong effects and heighten the risk of unintended overdose in NPS users. In vitro studies revealed that methiopropamine mediates its effects through inhibition of norepinephrine and dopamine uptake into presynaptic nerve terminals (IC50 = 0.47 and 0.74 µM, respectively), while the plasmalemmal serotonin uptake and vesicular uptake are affected only at high concentrations (IC50 > 25 µM). In summary, methiopropamine closely resembles methamphetamine with regard to its pharmacokinetics, pharmacodynamic effects and mechanism of action, with a potency that is approximately five times lower than that of methamphetamine.


2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Hedieh Zadeh - Abbasi Zarandi ◽  
Leila Shirani-Bidabadi ◽  
Abass Aghaei - Afshar ◽  
Mustafa Eghbalian ◽  
Jaafar Zolaala ◽  
...  

Background: Plant extracts or compounds derived from plants are a valuable source for finding new anti-leishmaniasis drugs. Objective: In this study, Capparis spinosa L., Ricinus communis, and Solanum luteum were used as lethal agents for the promastigotes of Leishmania major parasites in the culture medium. Methods: Diluted extracts of 12.5, 100, and 500 mg/mL were prepared from medicinal plant dried extracts. Glucantime at a concentration of 500 mg/mL was used as a positive control. Results: For all three extracts, concentrations of 100 and 500 mg/mL could kill promastigotes at higher rates and speeds compared to other concentrations. The high concentrations of extracts (500 mg/mL) presented similar effects. According to the findings, hydroalcoholic extract of C. Spinosa L. presented considerably lower antiparasitic effects, and S. luteum and R. communis extracts were could kill most of the parasitic promastigotes at higher doses. The ANOVA test did not show any significant viability percentage difference of Leishmania extracts between different extract types. Conclusions: In this study, the lethal effects of R. communis and S. luteum hydroalcoholic extracts on L. major promastigotes were found to be stronger than the C. Spinosa L. extract.


Sign in / Sign up

Export Citation Format

Share Document