جستجوی مقالات مرتبط با کلیدواژه « اسید سالیسیلیک » در نشریات گروه « گیاهپزشکی »

The olive fruit fly, Bactrocera oleae (Dip.: Tephritidae), is an important pest affecting olive crops, leading to substantial economic losses and diminishing both the quality and quantity of olive oil production. This study investigated the effects of salicylic acid (SA) treatments at concentrations of 1 mM and 2 mM, with a control, on the Manzanilla olive variety in Rudbar Olive Research Station, Guilan Province during 2021 and 2022. The results indicated that both the year and treatment factors had a significant effect on different developmental stages of olive fruit fly including egg, first, second, and third instar larvae and pupae. The treatment effects were significant across all measured traits. Damage assessments revealed that salicylic acid reduced the contamination of fruit to pupae and adult insects due to disruption in egg to larval formation. The year-related effects on various fruit morphological traits, including length, width, weight, volume, density, fruit flesh weight, and kernel dimensions were significant during the two years survey. The treatment effect was significant for all traits except for the width, fruit weight, and flesh weight of the fruit. Analysis of olive oil fatty acid composition demonstrated an increase in oleic and linoleic acids amount in treatments versus control. The concentration of squalene in healthy samples treated with 2 mM salicylic acid was significantly higher than control in 2022. These findings show that salicylic acid can be considered in olive fruit fly integrated management programs

The melon aphid, Aphis gossypii Glover is one of the most important pests in pepper fields and greenhouses, which is of special economic importance due to its wide distribution and large host range. In this research, biological and reprodutive parameters of A.gossypii on two pepper cultivars (Poblano and Paprika) treated with salicylic acid, were investigated at laboratory conditions (25 ± 2 ˚C, 65 ± 5 % RH, and a photoperiod of 16L: 8D h). According to the results, the use of salicylic acid in both cultivars had a significant effect on most of the demographic parameters of the A.gossypii, compared to the control (spraying with distilled water) and decreased its life span, life cycle length, and Survival. The lowest and highest lifespan were 5.91 days (salicylic acid treatment in Paprika) and 10.25 days (control treatment in Poblano), respectively. Also, the use of this hormone had a significant effect on the reducing gross reproductive rate (GRR), net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) of the aphid. The minimum and maximum values of r  were obtained in salicylic acid treatment on Paprika and control treatment on Poblano (0.2570 and 0.4046 d-1 respectively). So, salicylic acid can considerably reduce biological and reprodactive parameters of A.gossypii in pepper and can be used in integrated pest management programs of melon aphid.

Using plant resistance inducers leads to the reduction of disease incidence and severity. The effect of several resistance inducer compounds on onion downy mildew disease was tested in a factorial experiment with a randomized complete block design comprising of 10 treatments in 3 replications at Behbahan Agricultural Research Station. Treatments consisted of chemical indicers in five levels of 50mμ dipotassium phosphate, 80mμ nicotinic acid and 3mμ salicylic acid, and ridomil mancozeb fungicide (3g/L) and control that treated with water. Treatments were applied 5 times from mid-February when the plants were in 3 to 4 leaf stage until late April every two weeks. Genotypes were in two levels including modified onion of Behbahan and Early White Texas. Disease severity was calculated by evaluating 40 plants in each treatment when the disease index in the control treatment was more than 75% in two middle rows of each plot in each treatment. The highest percentage of disease severity (75.50%) was observed in the control treatment with no spraying and the lowest rate of disease severity was observed in the application of Ridomil with 14.17%. The severity of the disease was 28.33%, 33.33% and 23.33% in dipotassium phosphate, salicylic acid and nicotinic acid treatments, respectively. Therefore, the use of resistance inducers can be a substitute of fungicides.

Greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is a serious pest of a wide range of plants, such as common bean, cucumber, tomato, pepper, lettuce, etc, in both field and greenhouse production. It typically feeds on the underside of leaves, sucking phloem sap from the plant, which causes both direct damage, by overall weakening the plant and reducing yield, and indirect damage, by excreting honeydew, on which sooty mold grows, as well as transmission of several plant viruses. The widespread use of insecticides to control T. vaporariorum has resulted in developing resistance to the insecticides and affected human’s health and safety. The utilization of plant extract and elicitors is an environmentally safe method that is used in the control recently. Therefore, alternative control strategies are required to minimize the harmful effects of insecticides. In order to control this pest, environmentally friendly methods, especially of plant origin are recently considered by researchers. For this regard, the effect of some organic compounds including methanolic and n-hexanic extract of walnut’s husk or dill’s seeds and salicylic acid, individually and in combination with spirotetramat on population density of greenhouse whitefly’s nymphs and some secondary compounds of bean plant were investigated.
Seeds of common bean, Phaseolus vulgaris L. (Berloty cultivar) were sown and grown in 15-cm-plastic pots in a greenhouse at 25 ± 3°C, 50 ± 10% RH, and a natural photoperiod. For the experiments, potted bean plants at 6-8 leaf stage, highly infested with T. vaporariorum nymphs, were sprayed with 12 different treatments, including: (1) spirotetramat (SP), (2) methanolic extract of walnut husk (MW), (3) n-hexanic extract of walnut husk (NW), (4) methanolic extract of dill seed (MD), (5) n-hexanic extract of dill seed (ND, (6) salicylic acid (SA), (7) spirotetramat in combination with salicylic acid (SP+SA), (8) spirotetramat in combination with methanolic extract of dill seed (SP+MD), (9) spirotetramat in combination with methanolic extract of walnut husk (SP+MW), (10) spirotetramat in combination with n-hexanic extract of dill seed (SP+ND), (11) spirotetramat in combination with n-hexanic extract of walnut husk (SP+NW), and (12) water as a control (CO). After five days, the population density of T. vaporariorum nymphs on bean plants leaves was recorded. Furthermore, the effects of tested treatments on the total phenol and flavonoid contents of bean plants were evaluated. For this reason, dried leaves (5 g) from each treatment were used for the preparation of extracts. The total phenolic of the extracts were determined using the Folin - Ciocalteu reagent. Sample and standard readings were made using a spectrophotometer (Lambda 45-UV/Visible) at 765 nm against the reagent blank. Furthermore, the aluminum chloride colorimetric method was used for determination of the total flavonoid content of treatments. For total flavonoid determination, quercetin was used to make the standard calibration curve. The absorbance was read using a spectrophotometer (Lambda 45-UV/Visible) in the wavelengths of 415 nm. Data were analyzed by one-way ANOVA using SPSS 23.0 software. Comparison of means for nymph density using SNK (Student-Newman-Keuls) multi-range test and comparison of means for secondary chemical compositions using Tukey's test at probability level five Percentage occurred.
Results showed that the population density of greenhouse whitefly and the secondary metabolites of plant were significantly affected by the tested treatments. The lowest number of whitefly’s nymphs was on spirotetramat and spirotetramat in combination with methanolic extract of dill seed and the highest number was on control. Total phenolic contents ranged from 58.96 to 114.07 mg g-1 dry weight on different treatments, which the highest and lowest amount of it was obtained in spirotetramat in combination with methanolic extract of dill seed and spirotetramat in combination with n-hexanic extract of walnut husk, respectively. The highest amount of total flavonoid content of bean plants was in spirotetramat in combination with salicylic acid. The results of the present study showed that the density of greenhouse whitefly population in spirotetramate treatment was lower than other treatments but there was no significant difference with the combined treatments and methanolic extract of walnut husk. Also, all the treatments compared to the control significantly changed the population density of this pest and increased the amount of total phenolic compound in bean plant. Therefore, these compounds, especially the methanolic extract of walnut husk, can be used in integrated management programs of this pest.
This research could provide valuable information for control of T. vaporariorum in other plants like ornamental plants in the field and greenhouse and thus can be useful for the production of healthy and organic crops. So it can be used in the IPM programs of this pest.

Plant hormones are the compounds that are increased followed by the attack of herbivores to enhance plant defense ability. The idea of external application of hormones on crop plants to induce resistance to herbivores has been studied by examining the behavioral and physiological responses of tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae) on three tomato cultivars including Dehghan, Falat-111 and Mobil in response to jasmonic acid and salicylic acid hormone treatments by measuring the oviposition preference of the females, survivorship and development time of each immature stage and the concentration of soluble carbohydrates and phenols in the leaves. Oviposition preference of females and embryo development time on the susceptible cultivar, Falat-111, were significantly reduced and increased respectively in jasmonic acid treatment units. Larval development rate showed the highest response to hormonal treatments in the semi-resistant cultivar, Dehghan. Survivorship and development rates of the pupae were also significantly reduced under the influence of jasmonic acid treatments on all three cultivars. Despite significant differences in leaf soluble carbohydrates and phenols concentrations between control and sprayed tomato cultivars as well as a significant positive correlation between changes in carbohydrates and phenols concentrations in the experimental units, no significant correlation was observed between the aforementioned plant contents and insect biological variables. The results showed that these hormones in combination with appropriate plant varieties can be used to induce behavioral and physiological changes in the pest.

In this study, the effect of the low doses of gamma irradiation (10, 20, and 30 Gy) alone and in associated with the salicylic acid and indirect temperature on the seed borne infection of Bean common mosaic virus</em> (BCMV) was assessed. Commercial bean seeds called “Sadri” with seed borne infection to BCMV were sowed. The seedlings were tested for the infection of BCMV by indirect plate-trapped antigen (PTA- ELISA) test and seeded. Results indicated that the growth factors in the irradiated seeds alone and in associated with the salicylic acid or indirect temperature significantly increased (P≤0.05) in healthy and infected seedlings compared to the non-irradiated seedlings. Gamma irradiation induced the specific activity of various antioxidant enzymes (PPO, POX, CAT and PAL) as well as the total protein density in treated healthy and infected beans, and decreased the concentration of BCMV proteins in the infected and irradiated seeds alone and so in associated with the salicylic acid or indirect temperature compared to the non-irradiated seedlings. Results of this research indicated to the induction of the relative resistance against BCMV in infected bean seedlings treated with the 20 and 30 Gy doses of gamma irradiation alone or in associated with the salicylic acid and indirect temperature.

In this study the effect of different concentrations of salicylic acid (0, 200, 400 and 600 mg/l) on fungal growth and induction of resistance in wheat against Fusarium graminearum causl agent of head blight at 0, 24, 72 and 120 h after inoculation was investigated. Then the treated plants were inoculated with spore suspension ( at concentration of 106 spore/mL) by injection into the lower part of spikelet.The activity of antioxidant enzymes, total phenolic content and oxalate oxidase and β- 1,3- glucanase gene expression as indicators of resistance was assayed. The results showed that the highest rate of enzyme and total phenol production was related to concentration of 400 ppm and 72 hours post-infection. The analysis of genes expression by Real time-PCR showed that in72 hours after infection the concentration of 400 ppm had the most influence on the expression of both genes. The β- 1,3- glucanase gene in the same concentration had higher than oxalate oxidase. Effect of salicylic acid on inhibition of mycelium growth showed that the inhibitory effect was increased by increasing concentration and concentration of 600 mg/l absolutely prevent mycelium growth. According to the results it can be concluded that salicylic acid may be useful in the induction of resistance to head bligh.

In this study¡ response of 18 bread wheat cultivars were evaluated in interaction with five Mycosphaerella graminicola isolates from five provinces in seedling stage. In this experiment¡ the seeds were treated by 0¡ 0.75 and 1 mM concentrations of salicylic acid. According to the analysis of variance¡ significant difference (p

In this study، the ability of nematode-trapping fungus Arthrobotrys oligospora and salicylic acid (SA) were examined to control root-knot nematode، Meloidogyne javanica، in the laboratory and greenhouse conditions. Also changes of polyphenol oxidase (PPO) and peroxidase (POX) enzymes and total phenolic compounds accumulation in different treatments were studied. In greenhouse studies، we used leaf spraying of SA (5 mM) and soil drenching of A. oligospora (106 spore/ml) at six-leaf stage of the plants، separately and in combination. After 50 days of inoculation، diameter of the galls، number of galls and number of egg masses per individual plant، number of eggs per individual egg mass، root and foliage fresh weights were recorded. The data were analyzed in completely randomized design and subjected to analysis of Duncan’s multiple range test (p≤0. 05). The results showed that combined application of A. oligospora and SA were more effective compared to individual application of them. Study of changes in PPO، POX enzymes activities and total phenolic compounds accumulation showed that treatment with these factors caused increase in enzyme activities and also accumulation of total phenolics which shows induction of plant defense system.