مجله دانش گیاه پزشکی ایران
سال پنجاه و دوم شماره 2 (پاییز و زمستان 1400)

Root and crown common rotdisease caused by Bipolaris sorokiniana, has caused severe losses of wheat products worldwide. A collection of 147 monoconidial isolates was made from cultivated wheat in West Azerbaijan (Miyandoab), Golestan (Gorgan), Alborz (Karaj), Kermanshah (Kermanshah) and Fars (Shiraz) provinces in 2017-2018. After morphological and molecular identification, mating type primers were designed based on a conserved DNA binding (alpha domain) in MAT-1 and the high mobility group (HMG) domain in MAT-2. Frequency of mating type idiomorphs of B. sorokiniana isolates were done by multiplex PCR. Among 147 isolates of five population, 86 isolates amplified by MAT-1 primer and 61 isolates by MAT-2 primer. Frequencies of MAT-1 alleles in Shiraz and Gorgan populations was more than the MAT-2 alleles. According to the results of the Chi-square test (X2), Karaj, Kermanshah and Miyandoab populations had not significant difference (P<0.05). Therefore, these three populations have the highest potential for sexual reproduction than the otherthreepopulations. In addition, isolates from all of the populations were studied to evaluate the sexual fertility in vitro. After two months, pseudothecia without mature asci and ascospores formed in media.

Spodoptera cilium (Guenee 1852) is one of the grass pests in green space in the southern regions of Iran and many countries around the world. This study was conducted to evaluate the effectiveness of the two Iranian isolates of Beauveria bassiana (Bals.)Vuill including IRAN440C and IRAN441C on S. cilium larvae under laboratory and field conditions. The larvae were reared at 25±10 C, a relative humidity of 60±5%, and a 16:8 h (L:D) photoperiod on grass leaves. The effect of different concentrations of two fungal isolates on second and third larval instars was performed by two methods of larval dipping and grass leaf immersion with spore suspension. The results showed that in both larval instars, the percentage of mortality increased with increasing spore concentration. Based on the mortality rate for both stages, in both methods, the highest percentage of cumulative mortality (51.1%) was observed at a concentration of 5×106 spores of fungi per mL. As the concentration of the suspension increased, a significant decrease in the time required to mortality 50% of the larval population was observed. Our results indicated that the IRAN440C strain of B. bassiana at 5×106 spores of fungi per mL concentration was the most effective strain in terms of toxicity and high mortality in the population of S. cilium. Therefore, this strain can be used in control programs of grasslawn armyworm in urban green space.

Venturia canescens Gravenhorst is one of the important parasitoids of lepidopterous pests with worldwide distribution. For assessing the efficiency of natural enemies in biological control, it is necessary to study their foraging behavior. In this study, host stage preference (between 1st and 4th instar larvae), functional response (densities of 2, 4, 8, 16, 24, 32, and 64 of 4th instar larvae), and mutual interference of V. canescens (densities of 1, 2, 4, 6, and 8 of wasps) were studied on potato tuber moth, Phthorimaea operculella Zeller, larvae. In the preference experiment, the 4th instar larvae of potato tuber moth were preferred by the wasp. The logistic regression analyses revealed that the functional response of V. canescens to the 4th instar larvae of potato tuber moth was type II. Searching efficiency (a) and handling time (Th) of the wasp were estimated 1.174 h−1 and 1.1347 h, respectively. In the mutual interference experiment, the per capita searching efficiency of the wasp ranged from 0.0810 to 0.1111 h-1, with the highest value at the density of 1 and 2 and the lowest value at the density of 8 wasps. The slope of regression line or interference coefficient was estimated to be -0.1356, indicating the mutual interference among the wasps. Based on the results, the foraging behavior of V. canescens was affected by the developmental stage and density of the host, as well as the density of the wasps. So, V. canescens has a good potential for IPM programs of potato tuber moth.

Essential oils app;ication in integrated pest management as alternative or complementary to chemical insecticides appears quite safe and promosing. However the chemical instability, volatility and poor water solubility remain the main disadvantages of essential oils and must be resolved before being incorporated into pest management systems. Incorporation of essential oils into a controlled-release nanoformulation is an efficient approach to overcome these limitations. So the present study aimed to analyze chemical constituents of Mentha longifolia free and nanoencapsulated essential oils by gas chromatography–mass spectrometry (GC–MS) and describe a practical approach to synthesize nano hollow silica spheres by sol-gel method as a Mentha longifolia essential oil carrier. GC–MS analysis resulted in the detection of the 43 components, piperitenone (%32), piperitenone oxide (%24.01) and pulegone (%17.44) were the three most representative constituents. The success of M. longifolia essential oil encapsulated was characterized based on some parameters including particle size, zeta potential, polydispersity index (PDI) and encapsulation efficiency. The Optimised Reaction mixture consisting of TEOS (0.5 ml), CTAB (0.08 g), essential oil (1 ml), ethanol (13 ml), 25% ammonia (0.5 ml), 2 hours of ultrasonication at room temperature and emulsification at 15000 rpm for 5 min, resulted in particle size between 66 to 80 nm, a polydispersity index of 0.2, zeta pontencial of −37 mV and an EE of 79.64%.

Predatory ladybeetle, Cryptolaemus montrouzieri Mulsant is a beneficial agent in citrus orchards against scale insects. Effect of four insecticide treatments at recommended dose including mineral oil EC 10 ml/L, mineral oil mayonnaise 10 ml/L, insecticidal soap 2.5 ml/L and buprofezin 0.5 ml/L with control treatment (water) was evaluated on life table parameters of C. montrouzieri. The experiment was performed on fourth instar larvae and the offspring of emerged adults used to evaluate the life table parameters. The lowest mean number of eggs was related to buprofezin treatment (50.6 eggs) which was about 2.8 times less than the control (146.5 eggs). All tested compounds except mayonnaise oil 10 ml/L significantly reduced the intrinsic rate of increase (rm), the finite rate of increase (λ) and the net reproductive rate (R0) compared to the control. The life table parameters of C. montrouzieri were more affected by buprofezin treatment than other treatments, and these parameters were not significantly different in EC and palizin treatments compared with mayonnaise oil treatment. According to our results, simultaneous use of buprofezin with C. montrouzieri should be avoided in integerated management of scale insects. After confirming the results by conducting field experiments, alternative compounds such as mineral oils and palizin can be used.

The quality of host plants as the first level of nutrition and a key effective factor affect the biological ability of herbivorous pests. Green peach aphid, Myzus persicae (Sulzer), is an important pest of agricultural crops with the wide host range and the high ability to transmit important viral pathogens. This study was conducted to investigate the effect of foliar application of micronutrient fertilizers of Alpha Fe, Zinc sulfate, Copper sulfate and Manganese sulfate on some physiological and phytochemical characteristics of Capsicum annuum L., as well as some biological parameters of M. persicae under greenhouse conditions. Duration of different developmental stages of the aphid and estimation of biological parameters were recorded using the two-sex life table procedure. The results showed that the amount of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in plants treated with micronutrient fertilizers was increased. Also, the foliar application of micronutrient significantly was increased the activity of plant antioxidant enzymes during the nutritional interaction between the treated plants and the aphid compared to the control and the treated plants before aphid infestation. On the other hand, the plants treated with different micronutrients effected the biological parameters of aphid and the lowest life span and reproductive period, fecundity and longevity of adults were observed in plants treated with manganese micronutrient. According to the results, the foliar spraying of bell pepper with micronutrients can induce antibiotic resistance in it and possibly other plants hosting of M. persicae and be used in integrated management programs of this pest.

In this study, the efficacy of the biological material named as Rouin1 based on Bacillus subtilis BS106 in controlling Rhizoctonia root rot disease of sugar beet was evaluated. The experiment was carried out as split plots in the pattern of randomized complete block design in two research farms in Kermanshah county. The major factor was seed coating with Rouin1 at various conditions. The minor factor was irrigating and not irrigating the plots with Rouin1 solution. All of the plants were inoculated with R. solani RS 124 inoculum 8 weeks after planting. The results of this study showed that major factor as seed coating had no effect on disease severity or crop yield in different forms, but minor factor as irrigating with bacterial solution reduced disease severity and increased crop yield at 1% probability level. By applying irrigation treatment of Rouin1 commercial material at the rate of 200 g/ha at two stages of 45 and 90 days after planting, the average disease index decreased from 4.4 (average control treatment) to 3.58 (average irrigation treatment). As a result, the disease index decreased by 0.82 units (approximately equivalent to 8.2% of the infection rate). Also, the average yield increased from 39,560 kg in the control treatment to 48080 in the irrigation treatment, which is equivalent to 17.72% of production increasing per hectare.

In the present study, the pathogenicity of spores/crystals produced byBacillus thuringiensis subsp. kurstaki (HD-1) in different culture media within fermented and non fermented conditions were determined against the second larval instar of Ephestia kuehniella L. The colony forming unit (CFU), spore count, optical density (OD) and cell mass indices in enriched and non-enriched liquid media of fermented condition after 96 h cultivation were (28.2×‌1014 CFU.mL-1, 11.8×‌1010 spore.mL-1, 28.0×‌108 mg.mL-1 and 11.0 g.L-1) and (26.6×‌1014 CFU.mL-1, 10.0×‌1010 spore.mL-1, 24.4×‌108 mg.mL-1 and 9.9 g.L-1), respectively while those were found to be (18.1×‌1014 CFU.mL-1, 8.1×‌1010 spore.mL-1, 16.4×‌108 mg.mL-1 and 8.9 g.L-1) and (16.8×‌1014 CFU.mL-1, 7.4 ×‌1010 spore.mL -1, 15.6×‌108 mg.mL-1 and 7.9 g.L-1) in non-fermented condition, respectively. The LC50 value of Btk spore/crystal cultured on enriched and non-enriched liquid media for 96h cultivation in fermented condition after 2 days treatment against larval instar were obtained (0.9 and 3.0) and in non-fermented condition (1.5 and 4.2) µg.mL-1, respectively.The LT50 value in fermented condition (6.2 and 10.7) and in non-fermented condition (7.2 and 12.6) h were, respectively. Bioassay studies indicated that the Btk spore/crystal suspention cultured on enriched and non-enriched media in fermented condition for 96h cultivation after 2 days treatment had (61.0 and 46.6-%) and in non-fermented condition (53.3 and 38.6%) mortality, respectively. The results confirm that enriched culture medium in fermented conditions produced the highest amount of spores and crystals and thus increased bacterial toxicity on the second larval instar of E. kuehniella after treatment.

Identification the sources of seedling and adult plant resistance genes is important for gene pyramiding, gene deployment, and developing durable wheat cultivars to control the leaf rust with Puccinia triticinea Erickss agent. In this study, 218 Iranian wheat genotypes collected from different regions were cultivated in one-meter lines in the experimental farm of Golestan Agricultural Research Station in Ahwaz during 2019-2020 and treated with Khouzestan leaf rust prevalent pathotypes including LR-98-8, LR-98-5, LR-94-5 and LR-9-4. Seedling reactions with five prevalent pathotypes were carried out in a randomized complete block design with two replications in the greenhouses of the Cereal Pathology Unit of Seed and Plant Breeding Institute, Karaj. To evaluate resistance, we used Infection Type (IT), AUDPC (Area Under Disease Progression Curve), Final Disease Severity(FDS) and Coefficient Infection (CI) indices. The results showed that 10 percent and 7 percent of the genotypes are resistant in greenhouse and field conditions, respectively. In the adult plant stage, the responses of 23 genotypes were moderately resistant (MR) and 14 genotypes were moderately susceptible (MS). The correlation coefficients between the final disease severity, with the coefficient infection and rAUDPC were 0.989 and 0.949, respectively. Finally, 30 genotypes with the desired characteristics, ie final disease severity between 0-40%, coefficient of infection between 0-40 and rAUDPC between 0-30% were selected as the suitable genotypes. Cluster analysis classified the genotypes into four groups: susceptible (S), moderately susceptible (MS), moderately resistant (MR) and resistant (R).

Beet black scorch virus is one of the soil-borne sugar beet viruses in Iran. In this research work, we collected 80 samples of sugar beet farms in Razavi and Northern Khorasan Provinces. After extraction of their total RNA, the 3'UTR region of the virus genome was amplified to 315 nucleotides using reverse transcription polymerase chain reaction using specific primers. The 3'UTR of six different isolates was sequenced following cloning and then submitted to NCBI. Phylogenetic analysis based on nucleotide sequences of the 3'UTR region showed that the entire world isolates could be classified into two main groups II and I and each one was divided into two subgroups. Isolates of this study were grouped with 23 isolates from Iran in subgroup IA and Four isolates from Khorasan province were placed in the IB subgroup. Four Iranian BBSV isolates from the West were grouped in the subgroup GIIA. All Chinese isolates and the European isolates together with the USA isolate clustered in subgroup GIIB. The results of nucleotide comparison of six isolates showed that although no mutation occurred at position 3477 (uridine instead of guanine), However, in position 3398, adenine replaced guanine (similar to 60% of Iranian isolates) and in position 3393, uridine was substituted for cytosine only in Fariman isolates (MW274750). The results of comparing the average nucleotide identity of 3'UTR isolates in this study showed that they are identical to Iranian isolates in the range from 97.75% to 97.98%. Nevertheless, they had the least identity with Kermanshah isolates (92.52%).

This study investigated the effect of pre-maturity developmental time on adult longevity and mating behaviors of the cowpea weevil, Callosobruchus maculatus (Coleoptera: Bruchidae). Eggs of the same age and one-day-old virgin adult insects were used for the experiments. Longevity of adult insects associated with each developmental time, the number of eggs and hatching percentage, besides mating-related parameters, including mating success rate, males rejection rate, mating reluctance males, mating latency, onset time, and duration of kicking by the females and mating duration were recorded. The results showed that the length of the developmental time did not significantly affect the longevity of the female insects but showed a significant effect on the longevity of the male individuals. Male insects with a very short or very long developmental time had a shorter lifespan compared to the male insects that appeared in the middle of the period (with a medium developmental time). Male insects with longer developmental time had less ability to succeed against female insect resistance and eventually mating success. Copulation duration was also affected by the insect's developmental time length. In general, the cowpea weevil's developmental time directly impacts the longevity of adult insects, and their mating behaviors. In addition, attention to this issue is important in selecting insects for different experiments. It can play a significant role in reducing experimental errors.

In this study, the effects of dry grapefruit waste at levels of 3,5 and 7% (w/w) and sesame oil cake at 0.5, 1 and 1.5% (w/w) to control of the root knot-nematode Meloidogyne javanica within tomato roots in sterilized and non-sterilized soils were investigated under greenhouse conditions. Also, C:N ratio, roots total phenolic content, chlorophyll and growth factors of host plant were evaluated. The results showed that treatments of 7% grapefruit wastes and 1.5% sesame oil cake, in non-sterilized soil reduced the final nematode population by 54.5% and 83%, respectively. Increasing the percentage of wastes improved the growth indices of infected plants. The highest increases were in 7% grapefruit waste and 1.5% sesame oil cake in non-sterilized soil, and the lowest was in control and sterilized soil. The C:N ratio in treatments of 7% grapefruit wastes and 1.5% sesame oil cake in non-sterilized soil was 8.06 and 10.17, respectively. In comparison to the control, the amounts of total root phenol and leaf chlorophyll of nematode infected tomato increased. In the laboratory trial, the lowest survival rate of the nematode second juveniles occurred in treatment of 7% grapefruit wastes by 3.58% and in 1.5% sesame oil cake during 72 hours by 44.42% after 72 hourse. Inaddition, the lowest egg hatching rates after four days were 4.62% and 13.88% for these treatments, respectively.