شیده موجرلو

To identify the endophytic fungi of the caper plant, samples were collected from the healthy leaves, stems, and roots from Bushehr and Qom provinces during the summer and early autumn of 2022. Isolation and purification of fungal isolates were performed on potato dextrose agar and 2% water agar culture media, respectively. A total of 102 fungal isolates were obtained. Morphological characteristics and molecular data of the ITS region and TUB gene were used to identify the fungal species. Based on the results, Microascus cirrosus and M. terreus were identified as new endophytic fungi of caper for the first time in the world, and M. terreus was introduced as a new record for the funga of Iran.

To provide suitable models for predicting the temporal progress of barley leaf stripe disease caused by Pyrenophora graminea, epidemiological studies were conducted in 2019-2021. The temporal progress of disease was examined in five cultivars (Zehak, Nimroz, Auxin, Nowruz and Izeh) of barley in a randomized complete block design with four replications at Golestan Research Station in Khuzestan Province. Well-known epidemiological models such as Monomolecular, Logistics, Log-logistics, Gampertz and Weibel were used to assess the disease progress. The results showed that, in all cultivars, the log-logistic model is the most proper model in describing disease progress. In order to determine crop loss caused by barley stripe disease, 1000-kernel weight, yield and area under disease progress curve (AUDPC) during the growing season were measured. The results showed that the integral model using AUDPC as an independent variable and the loss percentage as a dependent variable in the Nowruz cultivar (L=33.241+0.0002AUDPC) can justify 50% of AUDPC changes against crop loss. In the multivariate model, disease severity at different stages was considered as an independent variable and yield was considered as a dependent variable. This model had high efficiency in estimating the amount of yield. The results also showed that disease severity in the early stages of disease symptoms and after heading is more important than other phenological stages in yield estimation. This multivariate model (Y = 4836.17 – 38.51X1- 33.78X7+ 16.83X28- 26.56X35) could explain more than 90% of changes in disease severity versus crop yield.

During the growth period, the potato crop is exposed to a combination of biotic and abiotic stresses. Rhizoctonia solani Kuhn is the causal agent of potato stem canker disease and one of the most important soil-borne plant pathogens that reduce the yield and quality of potatoes worldwide. Antagonistic bacteria seem to be a good alternative to chemicals in controlling plant pathogens. This study evaluated the biocontrol properties (hydrolyzing enzymes, siderophore, surfactant, biofilm) of 20 Bacillus isolates against R. solani AG3. In total, 23 to 64.9 % of isolates in dual culture assay, 38.2 to 85.4% in volatile compound production, and 76.9 to 90% in antibiotic production showed inhibition against the tested fungus. The isolates were variable in terms of biocontrol properties. Based on the in vitro results, five isolates including Ba1, Ba5, Ba8, Ba11, and Ba12 were selected for identification and additional investigations under greenhouse experiments. The selected isolates inhibited the germination of fungal sclerotium and caused mycelial fragmentation and cytoplasmic coagulation. Strains Ba1, Ba5, Ba8, Ba11, and Ba12 belonged to B. mojavensis, Bacillus sp., B. pumilus, Bacillus sp., and B. velezensis, respectively. In the greenhouse trials, the disease severity index was zero in treatments Ba5 (Bacillus sp.) and Ba8 (B. pumilus), similar to Rovral -TS fungicide and completely controlled stem canker disease. Therefore, they are suggested for additional investigations and preparation of optimal formulations.

The purpose of this study was to investigate the effect of heat treatment on biological resistance and some physical and mechanical properties of paulownia wood (Paulownia fortunei). Thermo-wood specimens were prepared from paulownia wood based on thermo-D process. Heat-treated and untreated wood specimens were evaluated after exposing to brown rot fungus for 16 weeks. The laccase activity and its effect on mass loss and wood density were investigated. Moreover, some mechanical properties including impact strength and compression parallel to grain was measured. Evaluation of laccase activity showed more efficiency of this enzyme in untreated specimens in compared with thermo-wood and also it resulted in more mass loss. Therefore, heat treatment can improve biological resistance. The results also showed that heat treatment reduces density and impact strength of specimens, but improve compression parallel to the grain. Investigation of physical and mechanical properties of specimens exposed to brown rot fungus also showed that heat treatment reduced efficiency of this fungus on paulownia wood. So that, the value of mass loss, density and compression parallel to the grain in controls were more than thermo-wood. However, reduction of impact strength of thermo-wood was more than controls.

Beans are major feed crops belonging to the family Leguminosae, representing one of the most consumed legumes in Iran. Root rot diseases account for high yield losses in bean crops annually, driving the need to identify causative pathogenic agents. During the cropping season of 2019, samples were collected from rhizosphere and infected plant tissues in Khomein county. Of the total 80 purified isolates, 19 fungal isolates were selected for morphological and molecular identification studies. Fusarium equiseti, Fusarium acuminatum, and Macrophomina phaseolina were isolated from the infected crown and root tissues. Their pathogenicity on bean cultivars (Yaghout, Dorsa, and Koosha) is reported for the first time from Markazi province. However, the pathogenicity of fifteen saprophytic and pathogenic fungi species that are isolated from the rhizosphere needs to be confirmed in further studies. Disease symptoms were found to be more severe on pinto beans than red and white beans. In all cases, molecular studies using ITS and tef genomic region confirmed the morphological results. Briefly, these fungal species are introduced as bean root rot causal agents in Khoemin county, which needs to be considered in upcoming breeding programs.

The potential of Trichoderma spp. for biocontrol of phytopathogenic fungi has been well documented. In this study, the wild-type isolate of Trichoderma aureoviride (Tv59) was treated with the target dose of 250 Gy as the optimum dose. Twenty-six mutants were preliminarily screened based on better growth rates. In vitro, antagonistic evaluation of the 26 mutants and wild-type was performed against two Macrophomina phaseolina isolates (F33 and H7). Six mutants (Tv2(4), Tv20(6), Tv25(6), Tv3(3), Tv4(5), and Tv3(4)) showed remarkable inhibitory activity and were selected for further examination in greenhouse trials. Greenhouse assessment of the selected mutants against M. phaseolina isolates revealed Tv20(6) and Tv25(6) as the most highly effective treatments screened for the measured indices. Moreover, the total genomic DNA of the wild-type isolate and its 26 corresponding mutants were analyzed to determine their genetic variability through the RAPD technique. Five RAPD primers generated different banding patterns and yielded a total of 178 amplified fragments, 172 amplicons (96.62%) were polymorphic. While the dendrogram obtained by UPGMA cluster analysis of combined RAPD fingerprints differentiated the wild-type from its mutants at approximately 40% similarity level, the mutants were categorized into two clusters. Based on Jaccard similarity coefficients, eight mutants (Tv25(6), Tv1(5), Tv14(5), Tv20(6), Tv3(4), Tv40(6), Tv33(6), and Tv14(6)) showed the lowest genetic similarities with the parental isolate. The possibility of improvement in biocontrol effectiveness of T. aureoviride through random mutagenesis and detection and differentiation of genetic changes induced by gamma rays using RAPD analysis was successfully proved in the present study.

The circulatory system is involved in the transport and storage of food and defense against microorganisms. The success rate of this system depends on the number and type of blood cells and their proper function against contaminants in the body. In the present study, the effect of Bacillus thuringiensis and temperature stress was investigated on homocyte abundance and phenol oxidase activity in fifth larvae of Plutella xylostella. In the first experiment, rapeseed leaves were treated with sub–lethal concentrations of bacteria and fifth instar larvae were bled at 12 and 24 hours after feeding on the leaves. In the second experiment, the larvae were exposed to 4 and 30 degrees Celsius for 12 hours and temperature stress was examined on their homocytes. The results showed that feeding on canola leaves infected with bacteria after 12 and 24 hours caused a significant increase in total cells, plasmotocytes and granulocytes and phenol oxidase activity compared to the control. Temperature stresses also increased the number of homocytes and phenol oxidase activity compared to the control, which was more significant in larvae that tolerated high temperature stress. Certainly, additional research is needed to be able to evaluate the possible use of microbial control methods against cabbage willow by recognizing the safety characteristics.

Caspian boxwood (Buxus hyrcana Pojark.) is one of the ever green hardwoods of Caspian sea forestes which, unfortunately; is endanger of overthrow. Furthermore, several hectares of its habitats in Gilan and west of Mazandaran are exposed to Blight and excessive wilt caused by Cylindrocladium buxicola, recently. This fungus is serious peril for survival and generation of these trees. Certainly, identification of this fungus characteristic can be benefit in election and development of management strategies. So this research with the aim of information increment about this fungus and its population features in Iran was carried out. Firstly, phenotype properties of C. buxicola isolates (including morphology and disease severity),which randomly have collected from different sites of boxwood habitats, were evaluated. Then genetic variety of the isolates was evaluated by rep-PCR markers. Based on morphological assessments including shape and growth of mycelium, length, shape and the number of septates of conidia, also length and vesicle characterization of stips, 52 obtained Iranian isolates identified as Calonectria pseudonaviculta. 21 representative isolates were selected based on pathogenicity.These isolateds showed different levels of pathogenicity. The results of banding patterns of rep markers were analyzed together and the 21 representative isolates categorized into 4 groups at 95% similarity, and they were scattered in three provinces. This investigation furthermore revealed that all examined isolates, belonged to the authentic Calonectria pseudonaviculta group having main and stable morpho-physiological characteristics, so it seems that in the disease control, the use of resistant cultivars is one.

In this study, to isolate and identify the root endophyte fungi, root samples of herbaceous plants were collected from the central regions of Mazandaran province during 2016-17. In laboratory, each root sample was cultured on PDA medium after surface disinfestation and incubated for a month at 25°C and continuous darkness. Fungal isolates were purified using the single spore and hyphal tip methods. Fungal species were identified based on morphological characteristic and ITS sequence data. In this study, 27 species belonging to 14 different genera including: Alternaria alternata, A.arborescens, A. burnsii, A. dumosa, A. solani, A. tenuissima, Botryosphaeria dothidea , B. auasmontanum, Curvularia australiensis, C. buchloes, C. spicifera, Cladosporium tenuissimum, Daldinia concentrica, Diaporthe bohemiae, Fusarium acuminatum, F. avenaceum, F. equiseti, F. oxysporum, F. tricinctum, F.verticillioides، Microsphaeropsis arundinis، Nigrospora sphaerica، Paraconiothyrium cyclothyrioides, Periconia macrospinosa, Poaceascoma helicoides, Preussia minima and Xylaria heliscus were identified. Among identified fungi Botryosphaeria auasmontanum, Curvularia australiensis, C. buchloes, C. spicifera, Diaporthe bohemiae, Microsphaeropsis arundinis, Nigrospora sphaerica, Paraconiothyrium cyclothyrioides, Periconia macrospinosa, Poaceascoma helicoides and Preussia minima are new for mycoflora of Iran. Except Alternaria arborescens, other fungi are introduced from their hosts for the first time, in Iran.

Faba Bean (Vicia faba) is an important legume among cultivated plants and Alternaria leaf spot is a serious disease that causes broad damages and yield loss in Golestan and Mazandaran provinces. In current research, sampling was carried out from Mazandaran and Golestan provinces. Morphological and molecular surveys of the obtained isolates showed that they belong to A. alternata species. In order to evaluate resistance of nine Faba Bean cultivars against Alternaria leaf spot, area under disease progress curve (AUDPC) were calculated in greenhouse condition. In addition, variation of some resistance related enzymes between resistant and susceptible lines were tested at different time intervals after inoculation. Statistical analysis showed significant difference between cultivars (P≤ 0.05). The Otono cultivar with the highest AUDPC and Zereshki cultivar with the least AUDPC were suggested as susceptible and resistance cultivars, respectively. The ANOVA of antioxidant enzymes showed positive effects on CAT, APX and GPX levels after inoculation (P≤ 0.01). Increasing in the amount of enzymes in incompatible interaction (Zereshki resistant cultivar) was greater than that of compatible interaction (Otono susceptible cultivar), indicates the role of these enzymes in activating plant defense responses in Faba Bean to interact with the pathogen and induce resistance. In general, the results showed that Zereshki cultivar with low level of AUDPC and high expression of antioxidant enzymes has high potential to be used in breeding programs for resistance to Alternaria leaf spot.

Fresh grapes (Vitis vinifera L.) show severe lesions at the post-harvest stage and during the storage period. Decreasing the quality of grapes in the post-harvest stage limits its consumption and commercialization. Some methods such as using bio-control agents, natural antimicrobials, physical methods, disinfectants agents ,GRAS, (ozone, ethanol, acetic acid) have been used to control Botrytis cinerea after harvest. Encapsulation of the essential oils will increase their ability by increasing the effectiveness of the essential oils. Currently, chitosan has been interested for encapsulating bioactive compounds, as they are generally known to be safe and possess superior biological properties such as biodegradability, biocompatibility and non-toxicity. The aim of this study was to encapsulate thyme essential oil in chitosan nanogels to enhance and maintain its antifungal effect against B. cinerea in vitro and in vitro on Shahroodi red grape.

For the purpose of this study, chitosan nanogels were first prepared and the infrared spectrum of chitosan-meric acid nanogels was measured using FT-IR430 infrared spectrophotometer at 20 ° C. The morphology of chitosan-meric acid nanogels and encapsulated essential oil was analyzed by SEM. Release test was then performed to determine the release rate of thyme essential oil encapsulated in chitosan-meric acid nanogels. Effect of chitosan-meristic acid nanogels at three levels of 0, 150 and 300 µl/L, pure thyme essential oil and thyme essential oil encapsulated in chitosan-meristic acid nanogels at three levels of 0, 75 and 150 µl / L in vitro and on the shelf life of grape fruits was studied under modified atmospheric conditions during 72 days storage at 2 to 4 °C. During storage, some traits such as firmness by manual penetrometer, electrical conductivity of fruit tissue, some components of fruit skin color and soluble solids were assessed by a refrectometer.

 Infrared spectroscopy (FTIR) results confirmed the successful coupling between chitosan amin groups and carboxylic acid-meristic acid groups and scanning electron microscopy image showed that the particle size of chitosan-meric acid nanogel was than 100 nm. The Comparison of the particle size in the present study with the previous studies on the size of chitosan-meric acid nanogels was smaller and more uniform. These differences could be related to several reasons, transform the long chitosan chain into smaller fragments by initial sonication, the important role of ultrasound in the reduction of the particle size and passing the nanogels through the filter. Release test showed that the diffusion of thyme essential oil from chitosan-meric acid nanogels has a two-step process. The chitosan-meric acid nanogels prepared in this study have hydrophilic (chitosan polymer) and hydrophilic (meristic acid fatty acid chain) regions, which led to the gradual release of thyme essential oil due to their hydrophobic nature. The results of the infected packaged berries confirmed that with increasing concentration of thyme essential oil, the antifungal effect was also increased. Evaluation of the effects of essential oil and nanogels - essential oils on grape berries infected with pathogenic spores showed the highest number of spores in control treatment (10.125 × 105 per ml) and the lowest number in NE2 (1.375 × 105 per ml) were observed. Coating treatments of chitosan-meric acid nanogel and thyme essential oil encapsulated in chitosan-meric acid nanogels showed better results at higher concentrations, but in the case of essential oil, lower spores were observed. The lowest electrical conductivity and discoloration, the highest L * component and chroma index were observed in thyme essential oil treatment with concentration of 75 µl/l. The results showed that the lower concentrations of the essential oil in the control of botrytis cinerea was better than the pure essential oils, whereas in the experiments on the storage of grape fruit, the treatment of thyme essential oil with a concentration of 75 µl/l It showed the most favorable result. Based on the results of the present study, the effect of essential oil nano-gel and essential oil alone on the shelf life after harvesting of grapes packed with polyethylene film confirmed that the essential oil performance was better than the essential oil nanogel. The lower performance of the essential oil nanogel than that of the essential oil alone can be due to inhibition of the essential oil diffusion through the packaging film while, the encapsulated essential oil release slower than the essential oil alone, it is likely to have an effect longer than expected in this study for the storage period of the grape. Considering this case and the antimicrobial capability of essential oil nanogel, it is necessary to investigate the effect of essential oil nanogel compared to essential oil on longevity of grapes for a longer of storage period.

In this study the cellulytic activity of different species of Iranian Trichoderma isolates including Trichoderma harzianum (NAS-H101), T. aureoviride (NAS-AV106), T. pleuroticola (NAS-P109), T. longibrachiatum (NAS-L110), T. ghanens (NAS-K108), T. virens (NAS- Vi114), T. atroviride (NAS-A113) and T. atroviride (NAS-A112) was studied. The extracellular protein concentration of these isolates was determined by the dye binding method of Bradford. The molecular weight of cellulase enzymes was studied using SDS-PAGE. The lowest extracellular protein production was observed in NAS-K108. The highest Endo and Exo-glucanase activity were observed in NAS-L110 and NAS-A113, respectively. The SDS-PAGE profiles had several enzyme bands such as cellobiohydrolases, endoglucanases and β-glucosidases. The NAS-K108and NAS-P109 had both enzyme bands of CBH I and CBH II, but other isolates had only a sharp enzyme band correlated to CBH I or CBH II. The highest synergy was observed in FPase of NAS-A112, that contained a large amount of Cel 6A (CBH II) and a minor amount of Cel 7B (EG I). The results indicated that NAS-A113 overproduces cellulases, ß-glycosidase, and the extracellular enzymes, which suggest that this species might be utilized as a biological agent and or a source of enzymes for cellulose degradation in colloidal cellulose.

Fusarium solani f. sp.cucurbitae races cause crown, fruit and root rots of cucurbits and economic problem for farmers. The aim of this study is identification of Fusarium solani f. sp. cucurbitae races which collected in Shahrood, Jiroft and Varamin, provinces of Iran using morphological characteristics and fungal-specific primers. Symptomatic cucurbit plants were collected from different fields in three provinces. After isolation and purification of the causal agents, pathogenicity test and DNA extraction were performed. Specific primers for TEF-1α gene were used to distinguish among different species of Fusarium and Fusarium solani. The isolates that showed a specific 658 bp amplicon on agarose gel were selected for subsequent PCR assay in order to detection of F. solani f. sp. cucurbitae race 1 and 2. PCR assays were performed with taxon-specific primers race 1 (505bp PCR product) and race 2 (425bp PCR product). Some samples amplified a 505bp amplicon which is specific for race 1 and was in accordance with morphological characteristics. In these isolates, 5 septate macroconidia were dominant that is specific to Fusarium solani f. sp.cucurbitae race 1 macroconidia. None of the isolates were amplified by race 2 taxon-specific primers. Our study showed that, race 1 of F.solani is the dominant race of the pathogen in Shahrood, Jiroft and Varamin provinces which can help to implement effective disease management strategies.

Trichoderma species have been famous for production of cellulases with relatively high enzymatic activity. However, attempts to use their cellulolytic enzymes in the bioconversion of cellulosic wastes have not been successful because of high cost of production and low enzymatic yields. This study aimed to obtain gamma-induced mutants of T. viride with enhanced extracellular cellulase production. Spore suspensions were exposed to γ-rays at 250 Gy as optimum dose. After irradiation, all germinated spores were grown onto PDA plates and mutant strains with better sporulation were selected and subcultured five times to test their stability. Cellulase activity was tested using Whatman No. 1 filter paper, carboxymethyl cellulose, avicel, bacterial cellulose and walseth cellulose according to the IUPAC recommendation. Extracellular proteins profiles of mutant strains were studied via SDS-PAGE. The maximum activity of total cellulase and avicelase were observed in the isolate of M21 (92.43 and 74.40 U/mg, respectively) and maximum endo-glucanase activity was observed in M18 mutant. The results of this study showed that the application of gamma ray led to a significant increase in Cellulose activity of 38 percent of mutant strains. Thus, this method could be used as a simple and efficient way to achieve strains with the ability to produce high levels of enzymes and other biological metabolites.

Wheat leaf septoriosis caused by Mycosphaerella graminicola is one of the most important and destructive diseases of wheat. Since the resistant cultivars are not durable, disease control is mainly based on using fungicides where the yield loss is considerable. But using one fungicide may cause resistance. In this study, the impact of falcon® fungicide on disease control of wheat septoriosis has been studied. The experiment is carried out by randomized complete block design with 4 replications at Khuzestan agricultural and natural resources research center. No fungicide treatment and Tilt® used as controls. Results of this study showed that Falcon® treatment had lower AUDPC, higher yield and thousands of kernel weight compared to control and Tilt®. Disease severity progress was similar in both Tilt® and Falcon® treatments. Based on the results of current study, Falcon® fungicide is a suitable alternative of Tilt® in periodic applications of fungicides to combat leaf septoriosis

This study was undertaken to find out the optimum physicochemical parameters of fermentation, i.e. pH, incubation temperature and incubation time for the cellulase enzyme production of Trichoderma harzianum. The extracellular protein content was estimated by the dye binding method of Bradford. Endo-glucanase (EG), exoglucanase (or Cellobiohydrolase; CBH), β-glucosidase and total cellulase activity were investigated. The molecular weight of cellulase enzymes was studied using SDS-PAGE. To identify the predominant catalytic components in optimum conditions of enzyme production, cellulases were separated by an adapted two-dimensional electrophoresis technique. Estimated optimum conditions for cellulase enzyme were found as: pH 6.5, incubation temperature 28°C and incubation time 72 h. The SDS-PAGE profiles showed several enzyme bonds such as CBHs, EGs and BGLs. The T. harzianumhad both enzyme bonds of Cel7A (CBHI) and Cel7B (EG). Finally, the results of the 2D PAGE analysis showed that the profile of protein in optimium conditions of enzyme production had several enzymes such as CBHs, EGs and the high values of cellulose activity due to synergism that occurred between the CBH and EG.

Stripe rust cause by Pucciniastriiformis f. sp. tritici is one of the most important diseases of wheat and can cause severe yield loss in many wheat growing regions of the world including Iran. To determine yield loss caused by this disease and evaluate the effect of some chemical components on reduction of yield loss in south of Iran, field experiments were carried out in split plot design with three replications at Ahvaz research station during 2014-2015. Three cultivars; Chamran, Virinak and Boolani, were used and artificial inoculation was performed using an isolate which was collected from south of Iran and designated as Yr27 race variant. Meanwhile the effects of propiconazole and some herbicides on yield loss reduction were studied. In this study, grain yield and area under disease progress curve (AUDPC) were measured. Statistical analysis showed that the level of the yield reduction was significantly different in the three studied cultivars and different treatments. Propiconazole could control the disease significantly. The highest yield loss was observed for cv. Boolani in both with (9%) and without (54%) fungicide treatments. Combined application of propiconazole and herbicides significantly reduced yield loss compared with using them separately. The results of crop loss modeling using integral and multiple point regression models showed that the integral model (L = 0.017AUDPC-17.831) could explain more than 69% of AUDPC variations in relation to crop loss in all cultivars. In multiple point models, disease severity at various dates was considered as independent variable and crop loss percentage as dependent variable. This model with the highest coefficient of determination had the best fitness for crop loss estimation. The results showed that the disease severity at GS39, GS45, GS50 and GS60 stages (Zadok's scale) were more important for crop loss prediction than those in other phenological stages.

Stem rust caused by Puccinia graminis f. sp. tritici (Pgt) is one of the destructive diseases of wheat in the world. The fungal pathogen can infect 365 different grass and more than 70 Berberis species. DNA sequences for the ribosomal RNA internal transcribed spacer (ITS) have proven suitable to explore relationships at the species and subspecies levels. An isolate of Pgt which was collected from Iran and designated as TTSSK was used in this study. Three samples of the isolate were used. ITS region of the samples was amplified and sequenced. Consensus tree based on Maximum Parsimony clustering method was produced by Mega 6.0. Iranian isolate of TTSSK was placed in a clade with P. graminis which was isolated from Berberis sp. and Pgt isolate from Tajikistan. The results showed that more than one conserved genomic regions would be informative to identify phylogenetic relationship of Iranian Pgt isolates and samples from different parts of the world. Complementary studies with more sequence data from other genome loci are in progress.

Rice blast, caused by Pyricularia grisea, is one of the most important diseases of this crop in Iran and all over the world. To evaluate the relationship between spore population (SP) and meteorological factors, SP was measured daily using spore trap during growing seasons of 2006-2008 in Rasht and Lahijan regions (Guilan province, Iran). Weather data including precipitation, daily maximum and minimum temperatures, daily maximum and minimum relative humidity and duration of sunny hours were obtained from weather stations which were five kilometers away from the fields. The relationship between spore population and metrological factors was evaluated by Neurosolution 5.0 software. Weather data and spore population were considered as input and output data, respectively. In this study, multilayer perceptron neural network, regression model and Log(x + 1) transformation were performed. To evaluate the model efficiency, correlation coefficient and mean square error were used. The results showed that the correlation coefficient (r) and mean square error (MSE) parameters were 0.55 and 0.03 in Rasht and 0.1 and 0.03 in Lahijan, respectively. The results also showed the potential of this model for modeling SP using meteorological factors; however more data is needed for validation of this model. There has been no previous report on modeling the relationship between SP and meteorological data using artificial neural network in Guilan province (Iran).

Wheat is the most important crop of Iran and black or stem rust disease is one of the most severe diseases threatning the wheat production. In order to identify new resistant sources against the new race of stem rust virulent on plant with Sr 31gene, the selected Iranian landraces accessions of National Plant Gene Bank of Iran wheat collection were evaluated. The most virulent isolate of Puccinia graminis f.sp. tritici (Pgt) that was from Dasht-Azadegan was used. Isolate purity was tested by propagation of single pustule on seven days seedling of Boulani susceptible cultivar in the green house. Pathotype identification was carried out by 45 differential lines of wheat stem rust received from ICARDA. The Pathotype used was pathogenic against Sr31, Sr36, Sr38 and Sr13 but it was not pathogenic against Sr24. During this study, 62 Iranian landrace accessions were evaluated for resistance against Pgt at seedling stage in the greenhouse. Seven days seedlings were inoculated by spore suspension. 14 days after inoculation based on Stackman et al. method, infection type was recorded. According to the results, the landrace accessions were divided into susceptible and resistant groups. The resistant group included 39 landrace accessions. Complementary analysis for identification of resistance genes by molecular markers is in progress.