نشریه پژوهش های کاربردی در گیاه پزشکی
سال دوازدهم شماره 2 (تابستان 1402)

Ash trees (Fraxinus spp.) are one of the most important ornamental trees in the green space of cities. To evaluate the fungi associated with decline and dieback of ash trees, the symptomatic samples from branches, trunks, and roots of two species of Fraxinus (European Fraxinus, F. excelsior and Van, F. rotundifolia) were collected from Ardabil and Namin during the summer and autumn of 2018–2019. From the 60 samples, 81 fungal isolates were recovered. Based on morphological features of all isolates together with sequence data of tef-1α gene and specific primers of some Fusarium and Neocosmospora species, 21 fungal species were identified, i.e., Alternaria, Chaetomium, Clonostachys, Cytospora, Fusarium, Microascus, Microsphaeropsis, Neocosmospora, Peyronellaea and Phialophora. Neocosmospora solani, Cytospora chrysosperma and F. oxysporum had the highest abundance, respectively. Pathogenicity test was performed by excised shoot for F. cerealis, F. equiseti, F. oxysporum and N. solani excided shoot method and for C. chrysosperma on excided shoot method and also on two years old ash saplings in greenhouse. Our results showed that all examined species except F. cerealis and F. equiseti cause discoloration of wood texture at the inoculation site. According to our knowledge, most of the fungal species identified in this study, are reported for the first time on ash trees worldwide. Besides, F. denticulatum is a new record to the Iranian mycobiota.

Tuta absoluta is one of the most important tomato pests in Yazd province. Geographic Information System (GIS) with integrated, accurate and timely information, which is the most important part of any management program, can be used to solve pest management issues. In order to determine and evaluate the distribution pattern of tomato leaf miner, a 1-hectare tomato greenhouse was selected around Yazd city. Data on pest population density were obtained through random sampling from the greenhouse surface. Based on the results of the nearest neighbor method, the distribution pattern in these communities in the beginning and middle of the cultivation was cumulative and at the end of the season was uniform. The Ripley k method also showed that the dispersion pattern was cumulative at the beginning and middle of the culture, which tends to disperse more with increasing distance. This pattern was observed uniformly at the end of the growing season. As a result of these two methods, this pest has a cumulative distribution in the early and middle of the growing season, so it is possible to control it according to the location in the greenhouse. The spatial distribution map of the pest was drawn through Kriging model in all parts of the greenhouse.

Potato tuber moth, Phthorimaea operculella is considered as one of the most serious insect pests infesting plants in the family Solanaceae. The indiscriminate utilization of chemical pesticides has caused problems such as environmental pollution, development of resistance in insect pests and undesirable effects on human and non-target organisms. Plant-based materials are one of the appropriate candidates as an alternative to synthetic chemical compounds that have the lowest risk to the environment. In this research, the insecticidal toxicity of chlorantraniliprole on different biological stages of P. operculella was compared with powder, essential oil and extract of Syzygium aromaticum. Oviposition-preference activity of adults and larval penetration rate were also studied. Based on probit analysis, the most sensitive stages to chlorantraniliprole, essential oil and extract of S. aromaticum were larvae (LC50= 3.39 mg/l), adults (LC50= 0.43 µl/l air) and adults (LC50= 241.54 mg/l), respectively. Although, chlorantraniliprole was effective in reducing the larval penetration rate, it did not have a significant effect on oviposition preference of adults. The results of this study showed that powder, essential oil and extract of S. aromaticum have a good potential to protect stored potatoes from P. operculella infestation and can be used for management programs of this pest.

Root and crown rot disease of apple trees is important in different regions of the world and causes considerable damage to apple orchards around the world annually. Due to the presence of newly known fungal agents in apple growing areas of Isfahan province, sensitivity of Fusarium solani and F. oxysporum species as the most abundant identified species of decay of apple trees compared to common fungicides including Tilt, Eminent, Cabrio Duo, Collis, Ortiva Top, Lamardor, Uniform, Flint, Stroby, Rovral TS and Topsin M at concentrations of 10, 25, 50, 100 and 200 mg/l were tested in vitro. Lamardor, Rovral TS, Ortiva top and Tilt fungicides at the highest tested concentrations in both Fusarium species and Eminent at all tested concentrations in F. oxysporum resulted in more than 50% mycelial growth inhibition in vitro, in comparison with the other fungicides. Although, performing a laboratory test is very useful in the initial screening of fungicides, but in order to definitively recommend a fungicide to control the disease, in addition to fungicides experiment in vitro, testing in greenhouse and field conditions is also necessary.

Root-lesion nematodes genus Pratylenchus are among the 10 most important plant parasitic nematodes in the world. Their economic damage as the third damaging group sometimes reaches 85%. In this research, the response of 100 landraces of spring bread wheat, 20 cultivars and two species Aegilops tauschii and Ae. cylindrica was evaluated to root-lesion nematode under greenhouse conditions in the form of a randomized complete block design. ANOVA analysis was done based on one-way analysis of variance and to compare the averages, the least significant difference (LSD) test was used at the probability level of 5%. The results showed that inoculation with nematodes led to a significant decrease in the growth indices. The effect of genotype and nematode inoculation on all phenotypic traits was significant at the 5% probability level. Based on the reproduction factor, the genotypes were divided into five groups with RF <0.36 (resistant), 0.36-0.58 (semi-resistant), 0.58-0.81 (tolerant), 0.81-1.03 (semi-sensitive) and RF > 0.03 (sensitive). Ten genotypes (8.2%) as sensitive, 12 genotypes (9.83%) as semi-sensitive, 30 genotypes (24.59%) as tolerant, 49 genotypes (40.16%) as semi-resistant and 21 genotypes (17.21%) were identified as resistant. A direct relationship between the nematode-related indices (RF and the number of nematodes per root weight) and the growth indices of plants after nematode infection was observed, so that the higher the nematode indices, the lower the plant growth index. This matter showed the significant effect of nematode on the studied genotypes.

Tomato bushy stunt virus (TBSV) is one of the important tomato viruses in Iran and all over the world. In this study, the effect of mycorrhizae in Tomato bushy stunt virus infection was investigated. For this purpose inoculum of mycorrhizal fungus Rhizoglomus irregulare was added to the plant growing medium at the time of tomato transplanting and after four weeks, TBSV was inoculated mechanically to the plants. The rate of virus multiplication was evaluated by Real-time PCR at time intervals of 19, 25 and 31 days after inoculation. The treatments included control plants (C), plants infected with TBSV (V), mycorrhizal plants (M) and mycorrhizal plants infected with TBSV (MV). The results of investigating the amount of virus accumulation in plants showed its decrease in MV plants compared to V plants, and this decrease was more obvious in more advanced stages of the disease. Investigating the expression level of AGO2 and MYB33 genes also revealed that these genes had a significant increase in MV plants compared to V plants. This increase indicates an increase in the resistance of MV plants to the virus compared to V plants and it also confirms the lower reproduction of the virus in tomato plants inoculated with mycorrhiza. The results of this research show that the use of mycorrhizal fungi as a stimulant of the plant's defense system may be a good way to defend against this viral disease.

Fusarium head blight disease of wheat causes economic damage on this strategic crop. This disease reduces crop yield and quality by lowering the grain yield and pose health risks to consumers via production of fungal toxins such as nivalenol and deoxynivalenol on the seeds. In this study the reaction of 25 commonly cultivated wheat genotypes were evaluated to Fusarium head blight disease under greenhouse conditions.The genotypes were inoculated twice at the time of spike formation and flowering, and after ten days, the disease incidence and the disease severity were calculated. Analytical results of data related to disease incidence, disease severity and seed contamination rate (thousand seed weight and number of seeds per spike) in greenhouse conditions showed that there is a significant difference between genotypes regarding the mentioned characteristics. Also, Irana, Niknejad, Gahar, Morvarid and Zagros were resistant genotypes, Wa-82-9 and Akbari genotypes were semi-resistant, Chamran, Karvan, Pastor, Chamran 2, Chenab, weebile 264 and Spring BC Roushan were semi-susceptible genotypes, S-90-5, Mehregan, Sholah, Flat, Hirmand, Alvand, Darab, Sistan, Zarin and Star genotypes were sensitive and also Bazh was recognized as very sensitive genotype. With the evaluation of resistance and semi resistance genotypes designated in this study, against this disease under field conditions, it will possible to recommend these genotypes for wheat production programs in different parts of Iran.

To evaluate the effect of tank mixing surfactants and nitrogen sources on the efficacy of tribenuron methyl herbicide, a greenhouse experiment was conducted as a factorial arrangement in a completely randomized design with four replications in the faculty of agriculture at Tarbiat Modares University in 2021. Experimental treatments included four rates of tribenuron methyl (0, 4.5, 9, and 15 g active ingredient (ai) ha-1), as a post-emergence herbicide: nitrogen sources (control without nitrogen, ammonium nitrate, ammonium sulfate, ammonium acetate, and asparagine amino acid): and types of surfactants (control without surfactant, amphoteric, anionic, and two non-ionic surfactants). The results showed that the values of greenness index, leaf area, and total dry weight were highest under control (no herbicide application), and decreased as herbicide rate increased. Application of nitrogen sources and surfactants with herbicide separately increased its efficiency compared to the non-use of additives, so that ED90 decreased from 15 to 6 by ammonium nitrate and ammonium acetate and from 15 to 14 and 11.02 g ai ha-1 by sodium lauryl ether sulfate and castor oil ethoxylate, respectively. The mixture of surfactant and nitrogen with tribenuron methyl was more effective than herbicide application with each of these additives alone. Generally, the application of ammonium nitrate, ammonium acetate, or ammonium sulfate with lauryl alcohol ethoxylate, ammonium nitrate with castor oil ethoxylate, and ammonium acetate with sodium lauryl ether sulfate are recommended.