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 Take-all is a devastating soil-borne disease of wheat Triticum aestivum L. The disease is caused by the pathogenic fungus Gaeumannomyces tritici, a pathogen distributed worldwide in major wheat production areas that causes severe damage to wheat production. Identification of genotypes with the high nutritional value of seeds can be considered in controlling this disease and in wheat breeding programs. Variation of high molecular weight glutenin subunits (HMW-GS) at the Glu-A1, Glu-B1, and Glu-D1 loci was studied using SDS-PAGE electrophoresis in 15 genotypes of bread wheat. A positive correlation was found between 1000-seed weight and the 5 + 10 allele (r = 0.594), indicating that presence of this allele will increase 1000-seed weight. A simple corresponding analysis was conducted to show the relationship between the take-all index and the genetic diversity of genotypes and the association between the bilateral groupings of individuals based on two criteria (genetic diversity and disease response). The result of stepwise regression showed that glutenin subunit null, 7 + 8, 2*, 7 + 9, 5 + 10 have linkage with resistance to take-all disease. Findings are useful in breeding programs to improve baking quality, develop uniformity and improve heterogeneous genotypes by selecting the best genotypes.

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The date palm fruit stalk borer is one of the most important pests of date palm in the world. Biochemical properties of digestive proteases in Oryctes elegans Prell larvae were investigated in this research and optimal total proteolytic and trypsin activities were obtained at pH 9.0 and 11.0, respectively. Activity staining of protease on SDS-PAGE showed one isoform. Also, zymogram pattern of trypsin using nitro-cellulose membrane revealed two isoforms. The inhibitory effect of PMSF, TLCK, TPCK, EDTA, iodoacetate and iodoacetamide were determined on O. elegans proteolytic activity. The iodoacetamide showed the highest inhibition on total proteolytic activity. Therefore, cysteine protease accounted for the major proteases in the gut of O. elegans. Total proteolytic activity was inhibited 22.3 and 12.15% by inhibitors extracted from Vicia faba and Lathyrus sativus, respectively. However, the inhibitors extracted from seeds of Prosopis farcta, Panecum miliaceum, and Alhagi maurorum showed negligible inhibitory effects on proteolytic activities. Trypsin activity was inhibited 91.5 and 82.3% by inhibitors extracted from V. faba and L. sativus, respectively. Electrophoretic analysis showed that inhibitors extracted from V. faba reduced the intensity of total proteolytic and trypsin activities. The inhibitor from V. faba was purified by ammonium sulfate precipitation and gel-filtration, also the molecular mass of inhibitor was determined 35 kDa. This purified inhibitor was able to inhibit trypsin activity by 72.7%. In addition, the highest inhibition of trypsin activity by inhibitor from V. faba occurred at pH 11.0. Also, the stability of inhibitor from V. faba was evaluated at different pHs and temperatures. This inhibitor was stable at pH 11.0 and 30 °C.

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Root and crown rot of wheat is caused by the fungus Gaeumannomyces graminis var. tritici. "Take-all" is an important disease affecting wheat, and its incidence has been reported in several provinces of Iran. To identify resistant cultivars, bread wheat germplasm should be evaluated. To evaluate bread wheat germplasm in response to Iranian isolate fungus (T-41) of Gaeumannomyces graminis var. tritici, 333 genotype of bread wheat, collected from different locations of Iran and other countries were evaluated to take-all in greenhouse conditions. Two experiments were conducted, the first with 89 and the second with 244 genotypes. The measured traits were amount of root and crown infection, disease intensity, wet and dry biomass, and height of shoots. Analysis of variance and means comparison for the parameters indicated that in the first experiment, two genotypes were resistant to the disease, and the rates of disease intensity in these genotypes were 0.13 and 0.06. In the second experiment, five completely resistant genotypes were identified with disease intensity ratings of '0'. The identified resistant genotypes screened from both experiments were re-evaluated, and the results were the same. Mean comparison between winter and spring types for dry weight and disease intensity showed that winter wheat is more resistant than spring type. The results of this research showed that there is resistance resource to take-all (T-41 isolate), in this germplasm.Since the experiment was conducted in greenhouse conditions, these genotypes should be tested against this disease in infected conditions at field. 

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In this study, the antagonistic activity of 1,000 bacterial isolates from different areas of Iran and two isolates of Pseudomonas fluorescens: CHA0 and UTPf5 were individually assayed against two isolates of Fusarium solani and two isolates of F. oxysporum that cause potato dry rot in Mashhad, Iran. Using in vitro dual culture plate technique, most of the tested isolates significantly reduced mycelia growth of Fusarium spp. on PDA after 7 days of incubation at 25^oC, compared to the untreated control. Thirty bacteria isolates with the most inhibition and P. fluorescens CHA0 were selected for experiments on potato tubers. All isolates were tested on tuber of potato cultivar Agria under in vivo conditions. There was no significant difference between rot diameter by P. fluorescens CHA0 and the infected control, but other isolates reduced dry rot development after 21 days of incubation at 25-27^oC, as compared to the untreated control. However, three isolates, namely, VUPf40, VUPf44, and VUPf506 that belong to the P. fluorescens species were the most effective. Talc-based formulation of these three effective bacteria and P. fluorescens CHA0 were assessed for their in situ efficacy against potato dry rot development, caused by F. solani FPO67, on treated tubers compared to the control. The formulation of these bacteria significantly decreased dry rot development, but only P. fluorescens VUPf506, with 79.8% reduction of fungi development, and 18.57% prevalence, was the most effective in reduction of potato dry rot in natural conditions. Based on these results, P. fluorescens VUPf506 can be considered as a promising alternative to chemical fungicides.
 

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 Enzymes play a crucial role in plant-pathogen interactions and are very important to manage plant diseases. Take-all is a disease (Gaeumannomyces graminis var. tritici) affecting the crowns and roots in wheat. So far, the resistance mechanism of this disease has not been identified; therefore, this research was performed to identify the components of resistance to this disease in a number of wheat genotypes. In this study, 8 bread wheat genotypes were cultured, and the changes in “peroxidase, Polyphenol Oxidase (PPO), Phenylalanine Ammonia-Lyase (PAL), and total protein” was assessed in 0, 4, 7, 9, and 12 days after inoculation. The results showed that different genotypes of wheat had different pathogenicity reactions to the take-all disease. Based on the average disease intensity, the genotypes were divided into three groups: resistant, moderately resistant, and susceptible. The results indicated that the level of polyphenol oxidase and phenylalanine ammonia-lyase, and the total protein increased in the resistant and moderately resistant groups. Cluster analysis by K-means was performed to produce three clusters. Polyphenol oxidase activity, phenylalanine ammonia-lyase activity, and total protein content in the second (resistant) and third (moderately resistant) clusters were higher than the first cluster (susceptible). Multivariate analysis indicated that peroxidase enzyme might indirectly influence the resistance. The results have clarified the role of polyphenol oxidase enzymes and total protein in enhancing resistance to take-all disease.

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Fire blight, caused by Erwinia amylovora bacteria, is one of the well-known plant diseases in the world including major diseases of the fruit trees, especially apples and pears. In recent years, due to chemical nature of the pesticides damaging human health and environment, the importance of biological control is considered as alternative measure to manage plant diseases. To investigate the possibility of biological control of the pathogens, healthy foliar samples of apple, pear, and quince trees were collected from different regions of Kerman Province, Iran, and then, biocontrol activity of antagonist agents was evaluated under laboratory conditions. On the basis of the results, some of the antagonists could decrease the symptoms of the disease by 14.28-79.59%. Laboratory evaluation included investigating the disease severity in immature pears, biocontrol activity of antagonist agents in the plate assay, inhibitory siderophore production, biofilm formation capacity, drought stress tolerance, and silver nanoparticle synthesis capability, which showed that these antagonist agents could potentially control the disease. Among the 9 well-performed antagonistic isolates from apples and pears, Vr87 isolate was selected. The studies were confirmed by amplifying part of 16S rDNA region of the isolate, using specific primers. By comparing the results on the NCBI website, the selected isolate was identified as Enterobacter sp. genus. Among all selected isolates as successful factors in controlling fire blight pathogen, including isolated isolates and isolates in the collection of Vali-e-Asr University, Bacillus subtilis strain BsVRU1 in the Vali-e-Asr University collection, with 73.5% inhibition, had higher inhibitory power than the other antagonist isolates against the pathogen of fire blight disease.