فهرست مطالب بتول صادقی

Soybean is one of the most important oilseed crops, supplying half of the protein and vegetable oil by humans. Charcoal rot disease and soybean crown and root rot caused by Macrophomina phaseolina and Phytophthora sojae, respectively, are among the most important soybean pathogens that cause a reduction in crop yield. A biocontrol strategy using Actinobacteria, especially different species of Streptomyces, and Hypocreaceae especially different species of Trichoderma, is considered a method for the management of disease and pests. In this study, biological control of these pathogens was investigated using Streptomyces sp. isolate 23 and Trichoderma sp. isolates 1 and their volatile metabolites. The activity of Streptomyces isolates and a Trichoderma isolate taken from the soil of Kerman was evaluated against pathogenic fungi, M. phaseolin, and P. sojae. Experiments in the laboratory were conducted based on a completely randomized design with three replications. Sequence analysis of 16s rDNA and ITS region showed Streptomyces sp. isolate 23 and Trichoderma sp. isolate 1 belong to S. bacillaris and T. longibrachiatum, respectively. The results of the double culture method and volatile metabolites test showed that S. bacillaris isolate 23 and T. longibrachiatum isolate 1, significantly inhibited the growth of M. phaseolina and P. sojae. In both tests, the two biocontrol agents used showed more inhibitory effects on P. sojae compared to M. phaseolina. The results of the dual culture and volatile metabolites tests showed that S. bacillaris isolate 23 and T. longibrachiatum isolate 1 had a high inhibitory effect on M. phaseolina and P. sojae.

Early blight is one of the major diseases of tomato that reduce the quality and quantity of the product. Regarding the molecular mechanisms involved in the host defense to the pathogen, little information is available to realize the mechanisms of defense response of tomato to pathogenic fungus Alternaria solani. In this research, the protein profile (proteome) of tomato leaves were investigated using two-dimensional electrophoresis. A total of 610 detection protein showed 29 different expression proteins in resistant and susceptible cultivars. These proteins mainly involved in stress and defense, energy and metabolism, photosynthesis, protein biosynthesis, and signal transduction. Proteins involved in stress and defense such as pathogencity related proteins (PR) and biosynthesis of phenolic metabolite were the most frequent. The most important defense mechanisms of the plant against A. solani were strengthening of the cell wall and antimicrobial phenolic compounds. The results of this study can be used to production of resistant varieties of tomato against A.solani.

Early blight disease is one of the most common foliar diseases of tomato, which causes a great reduction in the quantity and quality of its yield. Regarding the use of fungicides in controlling this disease, identification of plant defense mechanism against the pathogen can be useful in introducing resistant cultivars and controlling the damage of the pathogen. In this research, several biochemical changes and expression patterns of PR1b1 and WRKY33 genes were investigated by qRT-PCR in a resistant cultivar Super 2270 and a susceptible cultivar CH Flat infected with the fungus Alternaria solani. Sampling was done during five intervals with three replications. The hydrogen peroxide accumulation, activity of defense enzymes Guacul peroxidase, Catalase and Superoxide dismutase enzymes, and the number of transcripts of genes was found to be increased in a challenge with the pathogen. The activity of these enzymes and genes were higher in the resistant cultivar. H2O2 accumulated rapidly in the resistant cultivar leaf tissues and peaked during the early stages of infection, whereas accumulation was stronger and more intense in the susceptible cultivar tissues in later stages.These results indicated that the induction of oxidant/antioxidant responses and the activity of genes in this study are a part of the tomato defense mechanism against the necrotrophic fungus A.solani.

this research was invistigated activitiy of antagonistic activity of 200 soil Actinomycete isolates assayed against Phytophthora parasitica and P. citrophthora in Kerman Provice. Among all Actinomycetes, strains of 19 and 29 showed high level of activity in Agar disk and Well-diffusion methods. In both isolates, the active substance was water and metanol soluble but insoluble in chloroform. The investigation Greenhouse showed effects of four treatments pathogen, pathogen by antagonist, antagonist and control on high and dry wet root seedlings and length, wide leaves were significantly different at level 0/05% in completely randomized experimental design. Strin 19 on high and dry wet root seedlings and lenth leaves isolate and Strin 29 on wide leaves were most effective.From the results of our studies it is clear that usage of strain 19 and 29 as a biofungicidal natural product for application as an amendment in greenhouse soil mix inhibits or reduces the pathogen adverse effects. Antagonistic activity of two isolates in vivo confirm activity of biocontrol them in Greenhouse experiments.