Journal Of Crop Protection
Volume:10 Issue: 2, Jun 2021

A checklist for all known Iranian rust fungi including composition and distribution of the taxa was prepared. In the present checklist of Iranian Pucciniales, 470 rust taxa on 1133 vascular plants belonging to 60 plant families are recorded, making 1604 rust-host combinations. The presented data is based on 234 publications and the author’s surveys.

Aspergillus flavus is one of the important species of molds that can produce toxins during improper storage of wheat grains. In this study, different amounts of calcium oxide (0, 0.5, and 1%) were mixed with wheat samples containing mold spores. After 20 days, the samples were exposed to gamma radiation (0, 5, 10, 15, and 20 KGy). The presence of A. flavus, Aflatoxin B1 (AFB1), aflatoxin B2 (AFB2), aflatoxin G1 (AFG1), and aflatoxin G2 (AFG2) was assessed in samples. The results indicated that the effects of calcium oxide, gamma irradiation, and their interactions were significant on A. flavus, AFB1, and AFB2 contamination. Furthermore, other toxins like AFG1 and AFG2 were not found in the samples. An additional reduction in AFB1 and AFB2 was observed when irradiation was accompanied by Cao, and the maximum inhibition of aflatoxin production was achieved at 0.5% CaO. Consequently, based on the standard maximum limit of 10 KGy for cereals, the findings of this research suggest that 0.5% of calcium oxide and 10 KGy of irradiation could be applied in the storage of wheat grains to mitigate A. flavus, AFB1, and AFB2.

The seed-eater wasp, Bruchophagus verbasci (Erdös, 1969) comb. nov. (Hymenoptera: Chalcidoidea, Eurytomidae) is newly quoted from Iran. This species was originally described in the genus Eurytoma Illiger, 1807. Considering its morphological characters and the new finding of its biological association with some fabaceous plants, it was transferred to the genus, Bruchophagus Ashmead, 1888. It was redescribed and illustrated. Two fabaceous plant species, Astragalus brachydonatus Boiss. and Trigonella montana C. A. Mey. are revealed as host plants of B. verbasci for the first time. It is a new record for France, Morocco, and Turkey.

Flour mite Acarus siro (Acari: Acaridae) is an injurious postharvest pest of various stored products. The objective of this study was to investigate the effect of physicochemical characteristics of stored products on A. siro. In this research, the host preference and biology of the mite were studied in three varieties of rice, two varieties of sticky rice, and three different types of cheese. We considered the differences in grain granulometry (whole, broken, and flour) as variation in physical characteristics of the stored products, and proportions of basic nutritional content as variation in chemical characteristics. The results indicated that when offered to grain with different granulometry, A. siro selected broken grain as their host and oviposition site. Furthermore, the mite’s host preferences were also influenced by the nutritional content variation of the stored products. In biology experiments, the total development of A. siro lasted from16.78 ± 0.13 to 20.60 ± 0.51days and its fecundity ranged from 17.65 ± 1.75 to 53.05 ± 0.09 eggs per female. However, the results suggested that faster development and higher fecundity of the mite were generally found in a diet(s) with higher protein, fat, and water content. Additionally, we demonstrated that A. siro is better adapted to flour products, indicating the influence of particle size on the development and reproduction of the mite. Therefore, physicochemical characteristics of the stored products strongly affected the host selection and biology of A. siro, which in turn determines the degree of product susceptibility upon mite infestation.

The two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is one of the most important and destructive herbivorous mites in farm and greenhouse that has developed high levels of resistance to many acaricides. In this study, we investigated the effect of sublethal concentrations of hexythiazox at LC10, LC20, and LC30 on the development and reproduction parameters of Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) and its prey T. urticae. The crude data were analyzed based on age-stage, two-sex life table analysis. Hexythiazox (at LC20 and LC30 levels) reduced the oviposition period (9.68, 8.06 days), total lifespan (22.37, 20.88 days), and total fecundity (50.97, 46.21 eggs/female) compared to the control but did not affect those parameters of A. swirskii. The intrinsic rate of increase (r) and finite rate of increase (λ) were not significantly different at tested concentrations, but the net reproductive rate (R0), gross reproductive rate (GRR), and mean generation time (T) reduced significantly. Our study demonstrated lower toxicity of hexythiazox on A. swirskii compared to its prey. It could be concluded that the use of selective acaricides at lower concentrations may be helpful in integrated pest management programs.

Cucumber mosaic virus (CMV) is one of the most important viruses that globally cause disease outbreaks in horticultural, vegetable, and agronomic crops. To investigate the incidence of viruses infecting Achillea species (yarrows), 350 samples with mosaic, yellowing, and deformation symptoms were collected from different Markazi province locations during the spring seasons of 2017, 2018. CMV infection was detected by using DAS-ELISA. Five samples were selected for phylogenetic studies based on sampling areas and yarrow’s species. A 657 bp fragment of coat protein was amplified using specific primers of CMVCPr and CMVCPf in RT-PCR, cloned and sequenced. Obtained sequences of this study were compared with the retrieved sequences from GenBank. The identities of the CP at the nucleotide and amino acid levels were 95% and 100%, respectively, and are close to other Iranian isolates of CMV. Constructed phylogenetic tree showed that five Iranian isolates from yarrows were placed in the subgroup IB. This finding is the first genetic analysis of CMV from yarrow in Iran.

In this study, 32 plant samples with leaf spot symptoms were collected from Chaharmahal and Bakhtiari province, Iran, in the spring and summer of 2018. Isolation and purification of 26 fungal isolates were performed on 2% water agar and potato dextrose agar to identify the causal agents. Fungal species were identified according to morphological characteristics and molecular data obtained from glyceraldehyde 3-phosphate dehydrogenase (gpdh) gene sequences. In this research, 11 species belonging to four genera of hyphomycetous fungi, including Alternaria cantlous, A. consortialis, A. multiformis, Bipolaris sorokiniana, B. zeicola, Curvularia spicifera, C. nicotiae, C. inaequalis, Stemphylium beticola, S. symphyti, and S. vesicarium are introduced. Among them, three species, including C. nicotiae from Salvia officinalis L., S. beticola from Plantago major L., and S. symphyti from Mentha pulegium L., are reported as new records for mycobiota of Iran. All collected plant species are reported as new hosts (matrix nova) for the identified fungal taxa.

The present study is based on the material collected from East Azerbaijan province (Northwestern Iran) between July-August 2019. The specimens were collected using Malaise traps from a variety of habitats. Lycorina triangulifera Holmgren, 1859 were collected and identified. This species is the first record of the subfamily Lycorininae Cushman and Rohwer, 1920 (Hymenoptera: Ichneumonidae) in Iran. Morphological descriptions, as well as detailed illustrations of this species, are presented.

The specimens were collected from northern Iran using the sweeping net and Malaise traps during 2010-2019. A total of 25 species were identified, of which four species are recorded for the first time from Iran: Choerades femorata (Meigen, 1804), Dysmachus dentiger Richter, 1962, Heteropogon ornatipes Loew, 1851, and Neomochtherus schineri (Egger, 1855). Also, some species are new provincial records for the northern provinces of Iran. Local and global geographical distributions of all 25 species, diagnostic characters of the newly recorded species, and their photos are provided.

The cotton bollworm, Helicoverpa armigera (Hübner), is a destructive pest feeding on a diverse array of host plants. We studied the demographic parameters of H. armigera on artificial diets prepared from seeds of 10 corn Zea mays L. hybrids (KSC301, KSC403, KSC540, KSC600, KSC604, KSC704, KSC711, Maxima, NS770, and ZP677) using the age-stage, two-sex life table procedure. The results revealed that except for the incubation period, the Z. mays hybrids-mediated artificial diets significantly affected the length of the other immature stages. They also influenced the adult longevity, adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), and oviposition days of H. armigera. Furthermore, the total fecundity of H. armigera was affected by Z. mays hybrids. Accordingly, the females reared on KSC711 with 503.31 eggs had the highest total fecundity. The highest net reproductive rate (R0) (88.41 eggs/individual), the intrinsic rate of increase (r) (0.109 day-1), and finite rate of increase (λ) (1.115 day-1) were observed on KSC711. Our results provided valuable information regarding the life cycle of H. armigera on an artificial diet substrate prepared from different Z. mays hybrids. It was also revealed that although H. armigera had no significant differences in life table parameters on most hybrids, some of them, such as KSC711, were very susceptible to damage. One of the issues that emerged from these findings is the possibility of using some hybrids, e.g., KSC711, in the preparation of semi-artificial diets for this pest.

The black pod disease of cocoa in Ghana caused by Phytophthora palmivora and P. megakarya is traditionally managed with fungicides. Because of challenges associated with fungicide use, biological control options, if available, are worth trying. A fungus with proven usefulness in suppressing P. palmivora and P. megakarya in dual plate cultures and cocoa pods has partly been identified as an Aspergillus (designated AI_1). However, its exact identity has been unknown, requiring specific identification by comparing it with known Aspergillus flavus strains (designated AI_2, AI_3, AI_4, and AI_5). It was retested against P. palmivora to confirm the potency of AI_1. The putative A. flavus isolates were also tested for the first time against P. palmivora. Morphological features were determined on carrot agar (CA), potato dextrose agar (PDA), and malt extract agar (MEA). Genomic DNAs from the Aspergillus isolates were subjected to the ITS region and β-tubulin gene sequencing. All the Aspergillus isolates inhibited P. palmivora in assay plates by levels ranging from 89.33 to 95.33% (Experiment 1) and 46.67 to 60.33% (Experiment 2). Generally, the AI_1 produced culture features similar to those of the putative Aspergillus flavus isolates. ITS region sequence analysis grouped all isolates as A. flavus and beta-tubulin also grouped AI_1, AI_2, AI_3, and AI_4 as A. flavus but differentiated AI_5 as A. flavus var. parvisclerotigenus. AI_3 recorded the highest inhibition zone and prevented black pod development of inoculated pods as well. The previously unknown Aspergillus isolates AI_1 is now conclusively identified as A. flavus.

Fluorescence-activated cell sorting (FACS) as a novel and sensitive technology was used to evaluate the biocontrol efficiency of Bacillus subtilis against Agrobacterium tumefaciens, a very destructive plant pathogen. The combination of two methods of culturing and cell sorting by FACS technology was used to distinguish a rapid and accurate method in monitoring the biocontrol effect of Bacillus (ATCC21332) on Agrobacterium (IBRC-M10701 and AGL1),. The culture method indicated that the B. subtilis could suppress A. tumefaciens in vitro and in vivo. We used a green fluorescent protein (GFP), reporter, to flow cytometric analysis using FACS. The mean of GFP expression levels was significantly reduced to 17.98, 16.48, and 11.27% in treatments 24, 48, and 72 h post-treatment; however, it was 31.57, 26.06, and 23.98% in the nontreated ones. The experiments demonstrated a positive biocontrol effect of Bacillus against Agrobacterium. Overall, our findings may provide a basis for improving the new rapid biocontrol agent detection method based on FACS.

The codling moth (CM), Cydia pomonella (L.), is among the economically important pests of pome fruits. This moth causes tremendous crop losses worldwide annually. In the current study, 210 larvae from apple, pear, quince, and walnut orchards were collected from seven locations in Zanjan province, Iran. Four CM-specific microsatellite DNA loci, including Cyd10, Cyd11, Cyd12, and Cyd13, were analyzed by polymerase chain reaction (PCR). According to the results, the CM population sampled from quince showed the highest number of alleles per locus with the mean observed and effective allele numbers 1.75 and 1.51, respectively. The latter shows the number of alleles with equal frequencies that contributed the most to the observed heterozygosity. Also, the mean observed and expected heterozygosity for this population was 0.508 and 0.258, respectively. The increased observed heterozygosity confirms that the selection acts in favor of heterozygote genotypes. Large genetic distances were detected between the CMpopulation from quince and the populations sampled from the other host plants, the largest between quince and walnut populations. Further, among-population diversity contributed the most to the insect’s genetic diversity, which was 89%. Moreover, some of the populations had a deviation from the Hardy-Weinberg equilibrium (p < 0.001). While Cyd13 locus was more polymorphic than the other tested loci, Cyd11 locus was monomorphic. These findings reveal genetic variation in C. pomonella, collected from various fruit trees, indicating differences in some phenotypes noteworthy in integrated pest management.

Biocontrol agents have different growth and biocontrol responses under the influence of physicochemical parameters. The culture medium is one of these parameters. Therefore, in this study, the effects of eight liquid media were investigated on the growth and antagonistic efficacy of Trichoderma harzianum Tr6 against Phytophthora drechsleri. Tr6 at 108 spores per ml was grown in these media. All media pH was set at 5.5. Treatments were maintained under a light intensity of 206 Lux and 130 rpm at 28 °C for 10 days. Maximum sporulation (2.5 × 1010 spore/g.dw) occurred in Mol. C. (Sugar beet molasses and Corn steep liquor) medium. The most inhibition against pathogen was related to Mol. M. (Sugar beet molasses and Malt extract) medium. Mol. M. and Mol. B. (Sugar beet molasses and Baker yeast) had the most effect on disease reduction (58.33%). Mol. M. had not superlative effect on plant growth factors but had a better effect compared with other treatments except Mol. Y. (Sugar beet molasses and Yeast extract). The following assays were done to simultaneously select the optimum medium for high sporulation, effective control of disease, and plant growth promotion. Therefore, Mol. M., Mol. B., Mol. C., and Mol. C. B. M. media were used. Mol. C., Mol. C. B. M. and Mol. M. had the highest spore production with 2.35 × 1010, 1.83 × 1010, and 1.65 × 1010 spore/gdw, respectively. There was no significant difference between the Mol. C. B. M. and Mol. M. Furthermore, Mol. C. B. M. reduced disease by 62.5%, but this reduction was not significantly different from Mol. M. and Mol. B. Therefore, Mol. M. medium had the most influence on growth and biocontrol performance of Tr6.

Some saprophytic fungi were isolated during fungi isolation causing black spot or scab-like symptoms (genus Venturia) from Iran. One saprophytic isolate from apple leaf was identified as a member of the family Phaeosphaericeae based on morphological characteristics of pseudothecia, asci, and ascospores on oatmeal agar (OA). Mature pseudothecia were produced on OA after one-month incubation at 24 °C and continuous dark conditions; however, the pseudothecia produced on PDA were immature. Pseudothecia were dark brown and globose in shape. Numerous bitunicate asci formed in a broad hymenium. Asci were clavate, apically rounded, short pedicellate, with eight overlapping biseriate fusiform ascospores. Ascospores with the smooth wall, straight or slightly curved and slightly constricted at the second septum. Phylogenetic analysis based on sequence data of ITS and LSU regions of ribosomal DNA confirmed the morphological identification and specified the isolate as Neosetophoma poaceicola. The N. poaceicola is the first report from Iran and apple leaf in the world.