Journal of Applied Research in Plant Protection
Year:2022 | Volume:11 | Issue:3|Papers Count:11

In order to identify the new races, determine the virulence/avirulence formula and distribution of the causal agent of the wheat, in the spring of 2018 and 2019, respectively, 21 and 40 samples of leaf rust-infected leaves were collected from wheat fields in Khuzestan, Lorestan and Ardabil Mazandaran, Golestan, Kermanshah, Ilam, Sistan, Baluchistan and Fars provinces. The reaction of the isolates were evaluated by inoculating them on 38 differential lines under controlled greenhouse conditions. The results of this study led to the identification of 20 pathotypes and 13 races in the first year and 28 pathotypes and 11 races in the second year. PKTTS (28%) and PKTTT (18%) were the most prevalent races. The results of this study showed that differential cultivars carrying Lr19 and Lr9 resistance genes were resistant to all isolates and no virulence was observed on them. Lr2a gene with resistance reaction to 17 isolates was the most effective gene for resistance to wheat leaf rust after the two above-mentioned genes. Also, differential lines carrying Lr29, Lr10/Lr27+/Lr31 and Lr2b genes with resistance reaction to the majority of the isolates in two years were the most effective genes for resistance to wheat brown rust after Lr9, Lr19 and Lr2a genes.

In this study, toxicity of hexane, ethyl acetate and methanol extracts of Apium graveolens and Falcaria vulgaris were compared with the microbial insecticide Bt against 1st instars of Phthorimaea operculella. The aerial parts of plants dried in shadow, and were extracted using the above mentioned solvents via maceration method. The results revealed that after 24 hours’,exposure, ethyl acetate extracts of both plants were significantly more toxic than other extracts with LC50 values of 0. 21 and 0. 38 mg/l respectively. These extracts in addition with hexane extracts also were more toxic than Bt after 48 and 72 hours. The dose-response line slopes of methanol extracts of both plants were more than other agents otherwise less toxic than them. The best relative potency calculated as 69. 76 fold in comparing toxicity of Bt with ethyl acetate extract of A. graveolens which indicates the toxicant potential of this extract against PTM larvae. According to the results, Ethyl acetate extracts of both plants showed more AchE inhibitory activity in comparing with other extracts and 60-70% inhibition recorded by LC70 concentration of these extracts. Adults emergence reduced by 68-80% in LC70 concentration of ethyl acetate extracts of both plants. Life span of PTM larvae which treated with methanol and ethyl acetate extract of both plants, increased by 8 days in comparing with controls.

Grape leafhopper, Arboridia kermanshah is one of the important pests of vineyards in Sistan region, which weakens the trees and reduces the quality and quantity of grape production by laying eggs in the leaf tissue, and feeding on leaves and transmission of viral pathogens. During the recent years, grape leafhopper populations have increased sharply in vineyards in Sistan region. This study was conducted in 2019-2020, to evaluate the effect of some insecticides on grape leafhopper by spraying on the grape foliage. The studied insecticides were Thiamethoxam (Actara WG 25%), Thiaclopride(Biscaya OD 24%), Spirotetramat(Movento SC 10%), Imidacloprid(Confidor SC 35%), Fipronil(SC 5%), Chlorfluazuron(Atabron EC 50%) and Control. The insecticide efficacy, seven days after spraying in the first and second years were 100 and 90. 10% for Thiamethoxam, 99. 33 and 91. 06% for Thiaclopride, 99. 74 and 71. 97% for Spirotetramat 0. 75ml/lit, 99. 79 and 83. 14% for Spirotetramat 1ml/lit, 95. 63 and 97. 56% for Imidacloprid, 84. 22 and 71. 97% for Fipronil, 84. 13 and 66. 84% for Chlorfluazuron respectively. Fipronil and Chlorfluazuron had less effective on this pest compared to other treatments. In general, Thiamethoxam, Thiaclopride, Spirotetramat, Imidacloprid are suitable candidates for controlling grape leafhopper.

Sugar beet long snout weevil Lixus incanesncens is spread in almost all sugar beet fields in the Iran and causes economic quantitative and qualitative damage to sugar beet. In current study, the effect of four different sugar beet cultivars,Efesos, Anaconda, Aigrette and Premiere, on weight of adults, gut protein content, gut α,-amylase activity and its inhibition with rye and triticale seed protein extracts were compared. The highest weight (20. 33 mg) was seen in Efesos cultivar fed adults and no significant difference was recorded between the others. The gut protein content and α,-amylase activity in the adults fed on different sugar beet cultivars were different significantly and the least and highest values were recorded in Premiere and Efesos, respectively. According to the results, triticale protein extracts inhibited the gut α,-amylase activity of all adults fed on four sugar beet cultivars and there was no significant difference between them. The highest inhibitory rate (93%) was recorded in adults fed on Premiere. Also, the rye protein extract inhibited the Premiere fed adults digestive α,-amylase activity up to 98% and no significant difference was observed between the others. Consequently, rye and triticale protein inhibitors can be considered as one of the integrated pest management factors for the control of this pest. Also, Efesos and Premiere can be reported as desirable and undesirable cultivars for this insect, respectively.

In this study using with the Mirabilis antiviral protein (MAP), it was attempted to explore the MAP controlling effect mechanism as well its antiviral activity against the Cucumber mosaic virus-Fny (CMV) and Potato virus Y strain O (PVYº, ) under the greenhouse condition. Toward this aim, MAP was first isolated from different fractions of the crude extracts mixture of the leaves and roots of the four o'clock plant and then Nicotiana benthamiana seedlings were cultivated in 50 g pods and mechanically inoculated with the PVYO-UK (Acc. no. KY112748) and CMV-Fny (Acc. no. D00356. 1) at 4 to 6 leaf stages. PVYO inoculation was also separately done by the aphid. MAP was administrated directly into the rhizosphere area of the pods at the concentration of 300 μ, g in two days after and two days before seedling inoculations. Infection with each of the inoculated viruses in MAP treated benthamiana plant seedlings were then assessed by DAS-ELISA, 14 days after inoculations. Using with the Real-time RT-PCR, PVYO transcript levels was assessed at this time. Results showed that soil treatments of the benthamiana plant seedling with the MAP significantly decreased the titre of the tested viruses up to 14 days after treatments. Results of the Real-time RT-PCR indicated to the significant decrease in PVYO transcript level compared with the infected control plant. It was also revealed that MAP is more effective in controlling PVYO compared to CMV-Fny. Results indicated that MAP has not inhibited the PVYO transmission by the aphid vector. The dry and wet weights and the phenol content were also increased in benthamiana plants treated with the MAP.

Soybean cyst nematode Heterodera glycines is the most important factor in reducing the yield of soybean crop (Glycine max) in most of its cultivated areas in the world and is also spread in Iran in Mazandaran and Golestan provinces. In the present study, the reaction of 100 genotypes and soybean cultivars in the seed bank of Oilseeds Research and Development Company to soybean cyst nematode was evaluated. Genotypes were studied in a randomized complete block design with three replications under constant greenhouse temperature conditions. The race of soybean cyst nematode population was determined and identified using differential soybean cultivars. The results showed that 12 genotypes among Leflor, Bedford and Forrest as resistant,three genotypes including Chiquita, Centennial and Cloud as moderately resistant,26 genotypes as moderately sensitive and 59 genotypes namely Essex, Faur and Clark with susceptible check (Jk cultivar) as highly sensitive genotype to race 3 of soybean cyst nematode were identified. The results of cluster analysis based on nematode resistance, maturity group, seed color and umbilical color divided the genotypes into five groups. The most susceptible genotypes were in the second cluster group and the most resistant genotypes were in the third cluster group. Also, most of the resistant genotypes in terms of soybean maturity group belonged to groups V and VI of the maturity group.

Yellow mealworm, Tenebrio molitor, is a wealthy source of proteins and other nutrients. In this study, to improve the breeding of this edible insect, some of its biological parameters were evaluated by feeding on sixteen diets containing different levels of the antibiotic lincomycin (doses of 0, 0. 005, 0. 01 and 0. 02%) and probiotics. Probiotic levels included: 1-probiotic-free (p0), 2-commercial probiotic (pA), 3-probiotic prepared from culture of Lactobacillus bacteria (pB), and 4-probiotic containing commercial yeast (pC). All three probiotics were used at a dose rate of 1% (108 CFU/gr). Treatments were applied to first instar larvae in bran and carrot-based diet. Based on the results, a significant increase was observed in the larval life span in the treatment of pC-dose of 0. 01%, with an average of 67. 75 ±,1. 16 days, compared to the control (64. 17 ±,1. 04 days). The greatest mean larval weight, 144. 17 ±,5. 30 mg, was related to the pA-dose of 0. 01%, which was significantly different only with pC-dose of 0. 01% (117. 50 ±,3. 05 mg). The pupation percentage at zero dose (84. 46 ±,1. 77%) was significantly lower than the doses of 0. 01 and 0. 005% of antibiotics (8 and 9. 32%, respectively). Traits of pupal life span, pupal weight, adult weight and adult emergence rate were not affected by diets. Based on the findings, the interaction of antibiotics and probiotics can affect some growth and developmental parameters of the yellow mealworm that can be considered in insect breeding programs.

In this study, the possibility of chemical control against 1st instar larvae of leopard moth Zeuzera pyrina using peak flight time of adults, was assessed in walnut orchards of East Azarbaijan province. For this purpose, three areas were chosen in walnut orchards of Oskou and Azarshahr Counties. Pheromone traps were used to determine the peak flight time of leopard moth. The trees were sprayed with chlorpyrifos, imidacloprid, chlorpyrifos + imidacloprid, chlorpyrifos + indoxacarb, chlorpyrifos + fenvalerate and chlorpyrifos + cypermethrin, 12 days to two weeks after the peak of flight. Unsprayed trees were considered as controls. For damage assessment at the end of the growing season, eight to 16 trees were chosen from the control and treatment plots based on the plot area. Eight samples were taken per tree stratified as four main directions (N, E, S, and W) and two canopy levels (upper and lower half of the tree crown). Each sample was a 60 cm branch terminal. The number of larval tunnels in each sample was counted and recorded separately. Chlorpyrifos + cypermethrin had the greatest effect in reducing the number of larval tunnels (90. 75 %), and imidacloprid had the lowest effect (37. 5 %). Chlorpyrifos, chlorpyrifos + fenvalerate, chlorpyrifos + indoxacarb and chlorpyrifos + imidacloprid caused 51. 11 %, 87. 65 %, 83. 33%, and 79. 44 % reduction in infestation compared to control, respectively. All chemical treatments had significant difference with control at 0. 05 probability level. The results of this study showed that in high populations of the pest, the use of chemical insecticide can be recommended at the peak of the emergence of first instar larvae to reduce the damage.

Thrips tabaci, is one of the most important pests of onions, which due to its high fertility rate and high growth rate, quickly becomes resistant to pesticides, Therefore, integrated pest management and cultural methods is the best way to control this pest and prevent the emergence of resistant populations. This research was aimed to use nutrient elements and irrigation intervals in reduction of population and damage of onion thrips and was conducted as a factorial experiment arranged in completely randomized design. Treatments including irrigation intervals (4, 8 and 12 days) and nutrients (silicon, potassium, calcium and no fertilizer) were applied at four-leaf stage of onion, Zargan cultivar. The results revealed that the use of different fertilizers and irrigation intervals had a significant effect on the population and the amount of damage of onion thrips. The lowest mean number of T. tabaci was observed in the silica fertilizer treatment (13. 37) and the highest mean number was observed in control plants (without fertilizer) with an average of 40. 68 thrips per plant. Also, the highest damage to the leaf surface was observed in the 12-day irrigation interval (with an average of 42. 7%) and the lowest damage was observed in the 4-day irrigation interval and silica fertilizer treatment with an average of 27. 5%. According to our results, managing the irrigation intervals and types of nutrients, especially silica and calcium, which strengthen plant tissues, can reduce the onion thrips population and its damage.

The functional response of ectoparsitoid wasp Anisopteromalus calandrae parasitizing the 4th instar larvae of the cowpea weevil, Callosobruchus maculatus was investigated over host plant and complex patch treatments in the laboratory. In the first group of experiments, the effect of two different host plants including cowpea Vigna unguiculata L. and chickpea Cicer arietinum was studied on the functional response of the parasitoid wasp. In the second series of tests, the influence of patch complexity was investigated using chickpea as the host plant. According to the results of the logistic regression, the functional response for A. calandrae when attacking 4th instar larvae of C. maculatus on both chickpea and cowpea, and also in the complex patches of the host was type II. The search rates of the parasitoid were estimated 0. 0488 and 0. 0378 h-1, and the handling times were calculated to be 2. 0962 and 2. 1804 h in chickpea and cowpea treatments, respectively. In the complex patch using chickpea seeds as host plant, the estimated search rate value for A. calandrae (0. 0269 h-1) decreased in comparison with a simple patch (0. 0488 h-1),however, the difference was not significant. These results can provide useful information for the biological control of the cowpea weevil in silos and store places.

Leek yellow stripe virus (LYSV) (Potyvirus, Potyviridae), is one of the most important and prevalent viral pathogens of garlic (Allium sativum) causing significant yield losses worldwide. In this study, in order to identify LYSV, sampling was performed from Shushtar in Khuzestan province. For this purpose, 28 garlic leaf samples with chlorosis, mosaic and deformity were collected. Preliminary evaluation of the infection was performed using potyvirus-degenerate primers related to each of the CI (Cylindrical Inclusion) and NIb (Nuclear Inclusion body) genomic regions using RT-PCR test. Electrophoresis of PCR product on 1% agarose gel showed the presence of 700 and 350 bp fragments in 15 samples out of 28 collected samples, respectively. However, the results of nucleotide sequencing only confirmed the contamination of 3 samples out of 15 samples with LYSV. To complete the study, an isolate called LYSV-AE65 was selected and tested using two specific primer pairs for the complete sequence of CI and CP (Coat Protein) genes. The PCR product of each genome fragment was sequenced following cloning in the plasmid vector pTG19-T. In the phylogenetic analysis based on the nucleotide sequence of each of the CI and CP genes separately, no clear correlation was found between LYSV isolates similarities, their geographical origins and host range. Moreover, recombination analysis by RDP4 revealed that no potential recombination event/s happened between LYSV-AE65 from Iran with their respective isolates from NCBI in CI and CP genes. This study is the first molecular study of LYSV in Iran.