نشریه پژوهش های کاربردی در گیاه پزشکی
سال دوازدهم شماره 1 (بهار 1402)

Habrobracon hebetor is an important ectoparasitoid of several lepidopteran pests. The efficiency of parasitoids would be affected by insecticides applications. Integrating the application of biological control agents and insecticides for pest management requires knowledge about impact and selectivity of the insecticides on biological control agents. In this study, the lethal and sublethal effects of indoxacarb, Voliam Targo and profenofos were evaluated on different life stages and some behavioral responses of the parasitoid. Field recommended rate of Voliam Targo and profenofos caused 100 % mortality on adult female wasps. Based on bioassay tests, the LC50 values of indoxacarb, Voliam Targo and profenofos on adult stage were 172.5, 4.4 and 2.9 mg a.i./L, respectively. The result of bioassay experiments on adult stage showed that profenofos had higher toxicity against adult stage compared to indoxacarb and Voliam Targo. Field recommended rate of indoxacarb and Voliam Targo had low toxicity on immature stages of the parasitoid. The effect of LC30 of the tested insecticides on functional response as an important behavioral factor of parasitoids was also studied. The functional response of the parasitoid revealed a type II functional response in control and all of insecticides treatments. This study showed that the control and profenofos treatment had the shortest and longest handling time, respectively. The highest and lowest maximum attack rate was observed in profenofos and control treatments with 0.992 and 0.507 h, respectively. Evaluation of sublethal effects of indoxacarb, Voliam Targo and profenofos on orientation behavior of the wasp by olfactometer showed that the parasitoid preferred untreated host larvae compared with treated host larvae by tested insecticides. Results showed that profenofos had more negative effects on the parasitoid. Due to the high toxicity effect of Voliam Targo on adults, it seems that Indoxacarb would be a more suitable insecticide for using in integrated pest management programs.

Rhizoctonia root rot of common bean (Phaseolus vulgaris) caused by Rhizoctonia solani is among the most important soil-borne fungal diseases worldwide. In this study, nine arbuscular mycorrhizal fungi (AMF) including Acaulospora longula, Funneliformis mosseae, Gigaspora margarita, Glomus caledonium, G. claroideum, G. etunicatum, G. fasciculatum, G. versiform and Rhizophagus irregularis were evaluated for their effect on some growth traits and inhibition of R. solani in bean plants under greenhouse conditions. Six AMF species (F. mosseae, G. claroideum, G. etunicatum, G. margarita, G. caledonium and G. versiform) significantly reduced the disease severity index and the first four of these also reduced the incidence of disease compared with the infected control. The lowest disease severity and incidence were obtained by F. mosseae and G. claroideum, respectively. Compared with the infected control, the root length was significantly improved by all AMF. The other growth traits were also significantly improved by all AMF species with some exceptions as follows: root wet and dry weights (except G. fasciculatum), shoot wet weight (excep G. versiform), shoot length (except G. claroideum, G. versiform and G. etunicatum) and shoot dry weight (except G. etunicatum, G. fasciculatum, G. caledonium and G. margarita). Glomus fasciculatum had the highest root colonization. According to the results of this study, many AMF fungi improved plant growth and partially compensated for Rhizoctonia root rot on common bean, and they could be considered as good candidates for studying the biological control of this disease under field conditions.

Codling moth, Cydia pomonella L. (Lepidoptera: Tortricidae) is the key insect pest of apple orchards in Iran. This study was conducted in the main apple-growing regions of East Azarbaijan Province to generate potential habitat suitability maps of C. pomonella using MaxEnt modeling and to determine the importance of vegetation index in improving the accuracy of these models. Field surveys for collecting the occurrence data of codling moth were conducted during three growing seasons, 2017 - 2019. The activity of codling moth adult males was monitored using delta-shaped traps baited with female sex pheromone. Fifteen environmental variables were considered as potential predictors for estimating codling moth distribution. These variables were categorized into topographic, climatic, and remote sensing variables. A MaxEnt modeling algorithm was used to predict the distribution of codling moth. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC). By using the topographic, climatic, and topographic+climatic variables, the AUC values were 0.840, 0.951, and 0.938, respectively. The model including normalized difference vegetation index (NDVI) had the highest AUC value (0.99), which strongly supports model predictive power and indicates the importance of vegetation index in codling moth distribution modeling. NDVI was the most contributed variable in the model followed by precipitation of September, slope, minimum temperature of May, and mean temperature of April. The distribution map obtained in MaxEnt provides an important tool for identifying potential risk zones of codling moth. This map can assist managers in forecasting and planning control measures and therefore, effective management of current infestations of codling moth.

In this study, the effect of two fungal species and also a strigolacton phytohormone was evaluated on inducing resistance in two tomato cultivars infected with fusarium wilt disease. In this greenhouse experiment, two cultivars of tomato namely, Captain and 4129 and Trichoderma reesei, Rhizophagus irregularis and GR24 phytohormone (106µM) were used. For this purpose, a factorial experiment was used in a completely randomized design with three replications in different time periods after inoculation of the pathogen (0, 7, 15, 35 days). The effect of biocontrol treatments on changes of some antioxidant enzymes, phenol, total protein and disease severity was assayed. Data analysis showed that the highest activity of all three enzymes with different values for both cultivars occurred during 35 days after inoculation. Among combined and single treatments, application of a combination of three biocontrol factors (T. reesei, R. irregularis and GR24 phytohormone), respectively showed significant effect on increase of measured parameters compared with other treatments. Based on the results of this study it is suggested that application of all three agents in liquid form can be considered as a limiting factor for the growth of the pathogen on the seed surface besides inducing resistance against disease.

To evaluate the effect of Fusarium verticillioides on fresh weight, chlorophyll index, the activity of superoxide dismutase isoforms, and leaf proteins using two-dimensional gel electrophoresis in two corn lines, a factorial experiment based on a completely randomized design with five replications was performed with two corn lines B73 and MO17, infected with and without F. verticillioides under greenhouse conditions. The results showed that the effect of F. verticillioides on fresh weight was not significant, but it was significant on chlorophyll index in both corn lines. Electrophoretic analyses were carried out using 8% slab polyacrylamide gels. Superoxide dismutase was observed in three isoforms into polyacrylamide gels, and also these isoform activates were increased in plants infected by F. verticillioides. Leaf tissue proteome analysis of two corn lines showed that eight reproducible protein spots had significant alterations under F. verticillioides. These eight differentially expressed proteins were involved in the defense system and regulation processes. Isoform 2 of Mitogen-activated protein kinase 12 and Peroxiredoxin-2E, chloroplastic proteins involved in the defense system had overexpression under F. verticillioides in both corn lines. It seems that increased superoxide dismutase isoforms and proteins involved in the defense system can reduce F. verticillioides damage in the corn seedlings.

Scale insects (Coccoidea) cause lots of damages to plants every year. Some mites (Acari) as one component of the scale insect’s ecosystem, can reduce the population of these pests in case of not using pesticides. The aim of this study was to collect and identify some prostigmatic mites associated with scale insects that may have predatory relationship with scale insects or use scale insects as shelter. For this purpose, the scale insect infected parts of the host plants transferred to the laboratory and the related mites segregated. After process of clarification and slide preparation, 12 species belonging to 11 genera and seven families of Prostigmata collected and identified in association with 10 species from nine genera belonging to five families of the scale insects. Within these mites, a new record for Iranian fauna collected that showed with the asterisc (*). Prostigmata: Anystidae: Anystis baccarum; Erythraeidae: Abrolophus sp., Callidosoma sp., Leptus sp.; Iolinidae: Pronematus rykei, Pronematus ubiquitus; Microtrombidiidae: Eutrombidium sp.; Smarididae: Fessonia sp., Tenuipalpidae: Aegyptobia eriogonum*, Cenopalpus pulcher; Tetranychidae: Tetranychus urticae, Eotetranychus sp. Coccoidea: Eriococcidae: Acanthococcus isacanthus; Coccidae: Eulecanium tiliae, Coccus hesperidum, Saissetia oleae; Diaspididae: Diaspidiotus prunorum, Lepidosaphes malicola, Parlatoria oleae; Orthezidae: Orthezia urticae; Pseudococcidae: Planococcus citri, Planococcus vovae.

The greenhouse whitefly, Trialeurodes vaporariorum, is an important pest of greenhouse plants. To prevent the problems of using chemical pesticides in the greenhouse environment, it is necessary to use non-chemical methods. This study was carried out to evaluate efficiency of different colors and to determine the best light wavelength of sticky trap on tomato plants in greenhouse, during 2019–2020. Four experiments were carried out in a completely randomized design with 6 replications to evaluate the efficiency color of the sticky trap on attraction T. vaporariorum, throughout comparison between six colors (yellow, orange, green, blue, red, and white), and to evaluation efficiency height of the sticky trap on attraction, through comparison between three heights (30, 80, and 160 cm above the ground). Finally, the daily mean of trap capture and the light wavelength of the colored traps were measured. The results showed that, the orange and yellow colors had the best efficiency with the daily mean capture of 66.96 and 65.55 T. vaporariorum per trap, respectively. The most capture of sticky colored traps, was recorded at an installation height of 160 cm, with the daily mean capture of 115 T. vaporariorum per trap. The results of spectral measurement of traps showed that, the maximum wavelength reflectance in yellow and orange sticky traps were 580 and 600 nm, respectively. According to the results of this study, orange sticky traps with a light wavelength of about 600 nm, have the best efficiency in attracting and control of the greenhouse whitefly, T. vaporariorum.

Today, development of rapeseed Brassica napus cultivation has been considered due to the need to produce edible oil. Using chemical pesticides and fertilizers for the product increase has had detrimental effects on the environment and food safety. Applying probiotic agents could increase rapeseed improvement and growth factors besides promoting crop resistance to pests and diseases in sustainable agriculture. Thus, the endophytic role of Beauveria bassiana as the most well-known insect pathogenic fungus was investigated in five rapeseed varieties as Okapi, Nepton, Nafis, Nima, and Atura in terms of establishment and improvement of their growth indices. The seeds of these cultivars were treated by immersion in fungal suspensions of 106 and 107 conidia per ml and by coating with fungus conidial powder. Sampling was performed to determine the presence of fungus in the plant and to measure growth factors, until 21 days after inoculation. To re-isolate the fungus from the plant tissues, the tissues were plated on SDAY and evaluated after 10 days. The results showed that the fungus was well established as an endophyte in all varieties. Analysis of data on growth variables showed that there was a significant difference between treated and control plants for each variety. Nepton demonstrated a better response. Since this cultivar is one of the winter varieties that is commonly cultivated in Iran, seed treatment by the fungus could be used operationally in our country. This will improve the growth traits of the strategic plant, rapeseed, and increase the yield indices, ultimately.

Pesticides application is the main approach to manage Trialeurodes vaporariorum Therefore, the effects of azadirachtin, spiromesifen and thiamtoxam on whitefly and its parasitoid Encarsia formosa were investigated. In evaluating the lethal concentration of the treatments on eggs and 3rd nymph of whitefly, the highest lethal effect (LC50) was on egg and 3rd nymphal stage by spiromesifen and thiamtoxam were 89.55 and 76.25 ppm, respectively. The results of analysis of variance of treatment mortality on E. formosa after seven days showed that azadirachtin had the least adverse effect with 60% emergence of parasitoides and thiamtoxam had the highest adverse effect with 12% emergence for E. formosa. In assessment of the oviposition preference of E. formosa, among pesticide treatments, despite highest oviposition in low concentration of thiamtoxam and spiromesifen, but the highest egg hatching was related to azadirachtin. Also, the effectiveness of insecticides against whitefly nymphs in greenhouse and laboratory conditions was compared. The percentage of effect of treatments three, seven and 14 days after spraying showed that the greatest effect on nymphal stage was related to thiamethoxam with 80% mortality in three days after spraying, but in seventh and fourteenth days after spraying, was related to azadirachtin with 96.47 and 95.77% mortality, respectively. According to the results of this study, spiromsifen and thiamtoxam were effective in high population of this insect, but in integrated management program simultaneous use of E. formosa with azadirachtin is recommended.

Cauliflower Mosaic Virus (CaMV) is the first identified plant virus with a DNA genome and causes great economic damage to Brassicaceae plants. The successful production of capsids of this virus is useful both in its serological diagnosis and in the formation of virus-like particles (VLPs). In this research, DNA from cauliflower samples with suspected virus symptoms was extracted and the coat protein (CP) gene of the virus was amplified using specific primers in PCR. Then it was inserted into the expression vector pGEX2TK downstream of GST by digestion endonuclease enzymes BamHI and SmaI and after confirmation of the recombinant vector, its sequencing was carried out. Sequencing was performed and the sequence obtained in the NCBI database was compared with the sequences in the gene bank with the BLASTn program. It was found that this sequence is related to the CaMV virus with accession number KF357590.1 in the NCBI database. The expression of the CP was induced and optimized in E. coli (Rosetta strain). A very high expression of this protein was obtained at 37°C and 6 hours after induction using IPTG with a final concentration of 1 mM. Then, this protein was purified with sepharose nanoparticles which have an affinity to GST, and observed in SDS-PAGE. The related electron microscope images confirm the production of VLPs of this virus with correct assembly without creating inclusion bodies that can be tested in drug delivery in medicine.