roohallah saberi riseh

The production of siderophore and cellulase by Trichoderma species is one of the effective indexs in plant growth, effective control and management of pathogens as well as application in industry. Therefore, primary screening of best isolates is very important based on the defined indicators.

In this study, the optimal conditions for the qualitative and quantitative production of siderophore and cellulase were investigated using test plate method for the initial screening of 27 Trichoderma strains. For measuring cellulase enzymes (Endoglucanase, exoglucanase and beta glucosidase), the reactive dyes phenol red, congo red (0.5, 0.05 and 0.015%) were used at pH levels of 4, 5, 7 and 9 with carbon sources including Avicel, CMC and cellobiose. Quantitative measurement of cellulase was investigated using the dinitrosalicylic acid method. Screening of Trichoderma strains for siderophore production was studied by CAS agar method as mycelial culture and crude extract in a well method.

The results of this research showed phenol red 0.015% under pH5 is the best reagent for detection of cellulase, Because of there is no inhibition on mycelial growth and the purple zone diameter is clear. In quantitative cellulase assay, the highest enzyme specific activity is related to T. harzianum CT-763 with 3 U/mg. T. atroviride CT-482, CT-473 and CT-865 were known as active strains in siderophore production, which were able to produce two types of siderophore, hydroximate and catechol. The results of siderophore production in liquid medium using the well method showed that T. afroharzianum CT-891 has the highest siderophore production by creating a halo zone of 1.2 cm, while T. harzianum CT566 produced the lowest amount of siderophore without creating halo.

Considering the application efficiency using of siderophore and cellulase in sustainable agriculture and importance of the role of Trichoderma species in production these metabolites, the well method for siderophore and dinitrosalicylic acid method for cellulase detection suggested. In this study T. atroviride and T. harzianum species had the highest production in siderophore and cellulase, respectively

Crown and root rot is one of the important diseases of citrus trees in Iran. Various methods, including biological control, have been proposed to control this disease. Trichoderma species are widely present in all soils and plant materials. In this study, 27 Trichoderma strains were used for biological control of Phytophthora citrophthora. Measurement of cellulase enzyme and beta 1-3 glucanase produced by Trichoderma spp. was done using the dinitrosalicylic acid method. The results showed that the highest values are related to T. harzianum CT-763 and T. virens CT-9715 strains with 2 µmol/ml enzyme activity. Macroscopic and microscopic examinations of the dualculture of different Trichoderma strains with the pathogen, the inhibitory effect of volatile and non-volatile metabolites on mycelial growth of the pathogen were done. All Trichoderma strains and their volatile and non-volatile compounds inhibited on pathogen mycelia growth. The highest percentage of inhibition dualculture tests was caused by T. virens CT-9715. The highest inhibitory effect was determined for T. afroharzianum CT-891, T. aureoviridis CT-936, T. atroviride CT-865 with 100% and T. afroharzianum CT-55 with 50% in the non-volatile and volatile compounds assay, respectively. In microscopic examination of mycoparasitism effect of Trichoderma spp. and P. citrophthora, it was found that T. harzianum (CT-566, CT-862, CT-634, CT-873), T. afroharzianum CT-55 and T. aureoviridis CT-936, destroyed the mycelium of pathogen by a process such as twisting and lysis. For application of these successful local strains as biopesticide, it is necessary to perform additional studies on their biocontrol effects on Phytophthora in natural conditions.

Gummosis (Phytophthora Crown and Root Rot) is one of the Most Important Diseases of Pistachio Trees. In Order to Evaluate the Relative Resistance of 29 Rootstocks of Pistacia to this Disease, a Factorial Experiment was Conducted with Two Factors Rootstocks Type and Disease Stress, Based on Completely Randomized Design with Three Replications. Two-Month-old Pistachio Seedlings were Artificially Inoculated with Phytophthora Drechsleri and After Six Months, Evaluation Was Done. The Resistance of Rootstocks was Evaluated by Determining the Percent of Crown Rot Girdling, Disease Severity and Mortality Indices and Measuring the Stem Length, Stem and Root Dry Weight Traits in Control and Stress levels. The Results Showed that There was a Significant Difference Between the Studied Rootstocks in Terms of Resistance to Disease. The Disease Stress Caused a Decrease in Stem Length, Stem and Root Dry Weight of Seedlings. The Atlantica Had the lowest Amount of Crown Girdling (20%) and Disease Severity (17%) and in Terms of Disease Severity, it Showed a Significant Difference with other Rootstocks. The Sarakhs Rootstock Had also the Highest Amount of Crown Girdling (95%), Disease Severity (90%) and Mortality (55.55%) and in Terms of These Indices, it was Significantly Different from other Rootstocks. Therefore, Atlantica was the most Resistant and Sarakhs the most Susceptible Pistacia Rootstocks Against Gummosis Disease. The Cluster Analysis Divided the Rootstocks into Four Groups: Resistant (Atlantica, Integerrima and UCB1), Moderately Resistant (Mutika, Benebaghi, Kalleghouchi, Ghazvini, Gholamrezaei, Italiaei, Ahmad Aghaei, M5 and BK1), and Moderately Susceptible and Susceptible .

Pistachio is one of the most important agricultural products and iran has the richest germplasm of pistachio in the world. The presence of this genetic resources will be an appropriate opportunity for use in breeding purposes. Knowledge of genetic relationships among pistachio genotypes has important role in it’s breeding programs. Molecular markers are one of the powerful tools for studying plant phylogenetic relationships. Start Codon Targeted (SCoT) technique is one of the molecular systems that used to assess the genetic relationship among different plant species and cultivars. This study was performed in order to evaluate the genetic relationships between a numbers of Pistacia species and cultivars using SCoT molecular markers and to assess the usefulness of this markers in differentiating this genus.

Plant materials of this study are included 29 genotypes of domestic and wild species of genus Pistacia. A total of 25 SCoT primers were used to evaluate the genetic relationships. Genomic DNA were extracted from leaf samples using CTAB method with minor modifications. The quantity and quality of the extracted DNA were measured by spectrophotometer and agarose gel electrophoresis. Cluster analysis based on Jaccard’s similarity matrix and complete linkage algorithm and Principal coordinate analysis were performed using NTSYSpc 2.02e software.

In total, 449 DNA fragments were amplified by primers out of which 433 bands (96/43%) were polymorphic. The average number of amplified fragments for each primer was 17.96 bands with a mean of 17.32 polymorphic bands per primer. A number of species-spicific marker were detected in some Genotypes. The average of polymorphism information content values varied from 0/18 to 0/38. Also, the values of marker indices ranged from 0/56 to 4/36. The range of similarity coefficients of genotypes varied between 25% to 68%. Cluster analysis divided Genotypes into two main cluster including vera (domestic) and wild species. Principal coordinate analysis separated vera cultivars and genotypes from wild species and confirmed the results of cluster analysis.

The results of this study demonstrated that SCoT molecular markers detected high polymorphism among pistachio species and cultivars and differentiated the studid genotypes. Therefore, SCoT Marker is a useful tool for studying phylogenetic relationships in genus Pistacia.

Pseudomonas fluorescens bacteria are the most important rhizosphere bacteria that have a positive effect on vegetative and biochemical traits of the plant. In this study, genetic diversity of 22 Pseudomonas fluorescens strains and their effect on defense enzymes and growth factors of wheat plant were performed in three stages of greenhouse, molecular and biochemical evaluation. In molecular evaluation, 12 RAPD primers were used to evaluate the genetic diversity of strains. Biochemical evaluation was performed in 4 stages of 0, 3, 6 and 9 days after inoculation on wheat to measure the defense enzymes peroxidase and phenylalanine ammonialyase. VUPF5 strain on wheat increased shoot and biological weight. RAPD-PCR separated strains with similar geographic location and similar host. Greenhouse, molecular, and biochemical groupings identified almost the top strains. Strains 680, 738, 50, 354, 49, 58 and VUPF5, which had a positive effect on molecular evaluation in one group, were shared with the superior group of enzymes. T26-2 and F-68 in OP-I15 and OP-H8 primers amplified 1300 bp and 1200 bp bands, respectively witch these bands can evaluated after be further studies as candidate bands in the expression of these enzymes in wheat.

Due to the importance of mycorrhizal fungi and their ability in colonization of plants, the use of some microorganisms and chemical compounds to improve mycorrhizal activity is an important issue. In this study, an experminet  was conducted as a compeletely randomized factorial desin with  three replications at Valiasr University of Rafsanjan.Three fungal species, Funneliformis mosseae(FM), Rhizophagus intraradices(RI) and Rhizophagus irregalaris (RIr) were applied asmycorrhizal inoculant and the effect of some microorganisms including yeast (Issatchenkia orientalis) and bacteria (Pseudomonas fluorescens VUPf5) as well as chemical compounds such as compost tea, azolla extract, bacterial siderophore, humic acid and amino acid complex on fungal activity and physiological parameters of corn plant (SC750 cultivar) was examined. The results showed that all species of mycorrhizal fungi combined with bacterial treatment and chemical compounds had a significant effect on stem diameter and longitudinal growth, leaf area increase, root weight and dry weight and shoot dry weight. Variance analysis of SPAD showed that there was not significant difference between mycorrhizal and non-mycorrhizal treatments. However, the application of different species of mycorrhizal fungi had a significant effect on the content of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in compared to the control (without mycorrhizal fungus) treatment. The use of humic acid and compost had the extreme effect on plant growth. Amino acid complex treatment with Rhizophagus intraradices had the greatest effect on chlorophyll a, chlorophyll b and total chlorophyll content. The treatments of yeast and amino acid complex had the greatest effect on carotenoids, respectively..

Identifying resistant genotypes is necessary to control wheat take-all disease Gaeumannomyces graminis var. tritici. In this study, 30 bread wheat genotypes were evaluated under greenhouse and field conditions. The genotypes were evaluated with fifteen molecular markers (SSR and specific primers for translocation wheat-rye). The genotypes were divided into four groups based on disease severity (the greenhouse) and agronomic traits (the field). Chi-square results showed the interactions for these groupings. The correlation between disease severity and agronomic traits indicated that plant resistance is strongly dependent on plant yield. Based on cluster analysis for molecular data (based on simple matching similarity coefficient and UPGMA method), genotypes were separated into resistant and susceptible ones. The correlation between disease severity and amplified loci showed that disease resistance is interactive with xbarc232, xbarc124, and gpw95001 markers. Resistance to take-all disease is probably associated with the interaction of several genes. These results add significant information to our knowledge of the chromosomal location of genes for the take-all disease.

The current study evaluated Pseudomonas fluorescens VUPf5 and three isolates of Bacillus subtilis (GB32, GB12, and VRU1) for induction of resistance against Cucumber mosaic virus (CMV) in cucumber Cucumis sativus L. (cultivar Sultan) plants. Seed treatment with plant growth-promoting rhizobacteria (PGPR) strains significantly reduced the number of symptomatic plants when CMV was mechanically inoculated. Serological analysis using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) also showed a significant reduction in the CMV accumulation in plants treated with PGPR strains. In every treatment, growth indices, leaf chlorophyll content, leaf carotenoid content, leaf, and root Iron, Zinc, Copper, and Manganese concentration of virus-infected plants were significantly increased. The highest reduction in CMV concentration was observed in plants treated with VRU1. The maximum chlorophyll concentration, leaf Iron, copper, and manganese were observed in plants treated with GB32.
Nevertheless, the highest carotenoid content was measured in the VUPf5 treatment. In the case of growth indices, the best results were obtained by VUPf5 compared to untreated control. In addition, the production of lipase, siderophore, protease, cellulase, HCN, auxin, and phosphate carbonate was determined under in vitro conditions. All four strains were positive for siderophore and auxin production. These results suggest that P. fluorescens and B. subtilis should be further evaluated for their potential to contribute to CMV management under in vivo and in situ conditions.

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.

Root-knot nematode damage is one of the major challenges in Iranian pistachio production. In the current research, the potential of five isolates of Bacillus subtilis (B96, B95, B84, B48, B67) and Pseudomonas fluorescens VUPf52 were evaluated to manage root-knot nematode (RKN) Meloidogyne incognita in pistachio.

The experiment was conducted in a randomized complete block design with three replicates and different treatments depends on the assay.

In vitro experiments indicated that all B. subtilis treatments could kill second-stage juveniles with 100%, 63.80%, 63.33%, 87.14%, and 78.09% mortality at 72h, respectively. Under in vivo conditions, B96 and B95 were able to increase their population in the nematode infected soil more than other treatments. Compared to the control, these isolates also induced a significant decrease in the galling indices of nematodes, egg masses, and adult females per 0.5 gr of pistachio roots. Moreover, the results showed the significant effect of some treatments on the growth factors of pistachio plants. Bacterial suspension of B96 and P. fluorescens VUPf52 was applied as a soil drench under field conditions. Field assessments indicated that P. fluorescens VUPf52 was not significantly different compared with the negative control; although, B96 decreased the populations of second-stage juveniles (J2) the most.

It is concluded that B. subtilis products have the potential to be one of the components in the integrated RKN management in pistachio. Bacterial efficacy on M. incognita in pistachio orchards is reported here for the first time.

Phosphorus is one of the essential elements for plant growth and increase in the availability of indigenous phosphorus have an effective role in reducing the chemical fertilizers consumption. This study was conducted to investigate some inoculant formulations for phosphate-solubilizing fluorescent pseudomonads for agricultural and environmental uses. For this purpose, 30 isolates belong to fluorescent pseudomonad group were collected from microbial bank of Faculty of Agriculture of Vali-e-asr University of Rarsanjan. Then ability of all isolates for solubilizing tricalcium phosphate were studied. In addition, the ability of those isolates for increasing phosphorus availability in soil amended with and without phosphate rock at 15, 30 and 60 days was inspected. Finally, the persistence of the selected isolate was evaluated in some inoculant formulations. The results indicated that all isolates were able to increase the solubility of tricalcium phosphate in solid and liquid media of PKV and the pH of culture medium also decreased significantly. The maximum and minimum phosphate solubilization in solid media of PKV were related to isolates D33 and D24 and in liquid media, it was related to isolates D6 and D4 respectively. The results showed that isolates D33 and D35 increased the soil phosphorus bioavailability in 15, 30, 60 day after inoculation by 48, 25, 75% and 72, 50, 26% respectively. The cell numbers of D33 and D35 isolates in three inoculant formulations including talcum powder, talcum+rice bran and talcum+sawdust (180 days after inoculation) indicated that maximum and minimum of cell numbers of D33 were occurred in talcum powder and talcum+rice bran (105 cfu/g) and talcum+sawdust (8×103 cfu/g)  respectively. Maximum and minimum of cell numbers of D35 were observed in talcum+rice bran (105 cfu/g) and talcum+sawdust (10 cfu/g) respectively. Finally, inoculant formulation of talcum+rice bran was able to maintained an acceptable cell numbers of both isolates D33 and D35 (106 cfu/g) at the end of 150 days.

The present study aimed to investigation of root colonization percent and spore population of Arbuscular mycorrhizal fungi (AMF) in soils of 9 regions of Rafsanjan city. Also the effect of climate and some physical and chemical properties of soil including pH, EC, organic carbon, amount of absorbed P and B soil and amount of silt, sand and clay on these two factors were evaluated. Samples were collected from the rhizosphere of different plants and AMF spores were isolated from the soil samples using the wet sieve method. After root staining and spore extraction of spores from soil, root colonization and spore population determined. Az the results all samples have arbuscular mycorrhizal symbiosis. The average root colonization percent ranged from 17.7% in Western suburb to 83.3 % in Raviz and the average spore population per 10 gr of soil samples ranged from 5.68 in Western suburb to 139.2 in Davaran. There was significant and positive correlation between the spore population and root colonization percent (α= 0.01). There was significant and positive correlation between the percent of sand and organic carbon with spore population and root colonization percent (α= 0.01). correlation of measured indices with pH, EC, P, B, silt and clay showed significant and negative correlation(α= 0.01). furthermore, the results showed that the root colonization percent and spore population in each region is related to the host plant and climate as wel.

Plant growth-promoting rhizobacteria have great potential for increasing plant biomass and controlling plant diseases. Therefore PGPRs can be good substitute for the use of pesticides and chemical fertilizers in agriculture. For evaluation of the effects of antagonistic activities of several PGPRs against Pseudomonas syringae pv. lachrymans the causal agent of cucumber angular leaf spot disease in laboratory and greenhouse Conditions. Several bacteria isolated from different cucumber rhizosphere soil in Kerman province and a number of bacterial strains in the collection of Vali-e-Asr University of Rafsanjan were used. After in vitro screening, four isolates with ability of growth inhibitory effect were selected for further studies in vitro and in planta. Antibacterial activity characteristics of biocontrol agents such as production of secondary metabolites and some of their plant growth promoting traits were evaluated in vitro. During in planta study, the ability of bacterial strains to prevent the development of symptoms using the area under disease progress curve (AUDPC) and increasing the biomass of cucumber plant were evaluated. Greenhouse study showed that Pseudomonas fluorescens VRPF 54 strain have high biocontrol efficacy. During in planta study, this strain, both alone and in the interaction plant-pathogen in comparison with the control plant, significantly increased biomass and controlled cucumber leaf spot disease. After selection of this strain, some its antagonistic activities, biochemical properties and molecular identification were screened in vitro. Also, the assay of antioxidant enzymes activity such as peroxidase, guaiacol peroxidase, phenylalanine ammonia lyase, polyphenol oxidase and total phenol content were considerably increased.

Colonization and population of antagonistic bacteria on rhizosphere have a definite role on their antagonistic effect. In this study in order to determine optimal population density of antagonistic bacteria, in a way that they would be able to induce maximal defensive power in plant, and also in order to investigate effect of initial inoculated population and amount of plant defense enzymes, microelements uptake, chlorophyll and carotenoids; level of peroxidase, polyphenol oxidase, phenylalanine ammonia lyase, total phenolic compounds, total protein, Zn, Fe, Mn, chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in population of 104, 106 and 108 of four antagonistic bacteria Pseudomonas fluorescens VUPF5, P. fluorescens T-17, Bacillus subtilis V1 and B. subtilis 96 in Sarakhs cultivar of pistachio was measured. Experiments were done in randomized complete block design with three replications per each treatment. Studies showed in the measured factors despite of diverse results in bacterial populational treatments, all populational treatments follow a constant pattern in a way that along with increasing in bacterial population, amount of measured enzymes, total phenol content, microelements, chlorophyll and carotenoids increases.

Bean yellow mosaic virus (BYMV) which belongs to Potyvirus genus, is able to infect wide range of plants because of its wide host range. This virus is transmitted by mechanical inoculation and aphid vectors in non-persistent manner. In this research the effects of six treatments including: synthesized silver nano particles of P. fluorescens CHA0, preparations of T. harizianum and P. fluorescens CHA0, olive (Olea europaea) and yarrow (Achillea millefolium) extracts and potassium phosphite on damage reduction in three common bean genotypes against a BYMV isolate was investigated. This experiment was carried out in a completely randomized factorial design. For this purpose, treatments were applied on plants immediately afterward first symptoms in mechanically inoculated plants were appeared. Virus concentration in treated plants was evaluated by DAS-ELISA test using BYMV polycolonal antibody. Evaluation of vegetative and reproductive parameters, measurement of peroxidase and polyphenol oxidase enzymes activity and virus accumulation indicated that potassium phosphite, silver nano particles of P. fluorescens CHA0 and yarrow extracts had highest influence on virus accumulation

The use of plant growth-promoting rhizobacteria (PGPR) is a promising method in sustainable agriculture and can be an efficient alternative to chemical pesticides.

In this study, antagonistic features of four bacterial strains, including Pseudomonas fluorescens VUPF5, P. fluorescens T-17, Bacillus subtilis V1, and B. subtilis B96 were investigated. In addition, their effects on crown and root rot of pistachios (gummosis), caused by Phytophthora parsiana, were assessed. Besides, different populations (104, 106, 108 CFU/ml) of bacterial strains on the fresh and dry shoot and root weight of pistachios in the Sarakhs cultivar were evaluated.

The results showed that all bacterial strains had remarkable antagonistic effects and were capable of controlling pistachio gummosis under greenhouse conditions. P. fluorescens VUPF5 had the strongest effect among the selected strains under laboratory and greenhouse conditions, with a 70% reduction in the mortality rate. Upon a reduction in the initial inoculated population of the bacteria, their growth-promoting effects on growth factors in pistachio seedlings decreased.

Research should be carried out on the efficiency of the selected rhizobacteria strains by utilizing them under field conditions to evaluate their effectiveness in interaction with other microorganisms.

One critical environmental stress that limits plant production and development is salinity stress. Recently it has been shown that application of plant growth-promoting rhizobacteria (PGPR) can alleviate the deleterious effects of environmental stresses. Present study aimed to evaluate the effects of some bacterial strains on proline, sugar, total phenolic compounds (TPC), Phenylalanine ammonia lyase (PAL), photosynthetic pigments and antioxidant activities (guaiacol peroxidase, polyphenol oxidase and superoxide dismutase) of cucumber plants under salinity stress. A completely randomized design was applied with a factorial arrangement of two factors: salinity at three levels (0, 50 and 100 mM) and Pseudomonas fluorescens and Bacillus subtilis strains, with three replications. The results showed that cucumber plants that were inoculated with Pseudomonas and Bacillus strains possessed noticeable variations in proline, sugar, TPC, PAL and enzymes activity compared to un-inoculated control. These results suggest that use of these bacterial strains overcame harmful effect of salinity by accumulation of proline, TPC, sugar, PAL activity and enzymes activity that can be considered as a suitable method to manage salinity stress.

Plant growth which promotes rhizobacteria (PGPR) has a potential role in controlling root-knot disease. To reach the aim of this study, we used rhizobacteria replaced by chemicals to reduce this problem in Pistachio trees. Based on the previous studies, some strains with high ability were selected to reduce root knot severity. Three different formulations were prepared, using different carriers of materials named; wheat bran, dried apple and talc powder. we have used six individual strains of P. fluorescens and one combination of two strains (Vupf506+Vupf52). These formulations were tested to control M. incognita in Pistachio seedlings in the greenhouse condition. The wheat bran based treatments was effective in reducing disease by 32.7 to 88.9%. The bacteria survived longer in wheat bran-based and talc-based formulations than in dried apple-based formulation. The results of the study indicated that organic carriers can be efficiently used to improve the stability and efficiency of biocontrol-active microorganisms in controlling the Pistachio root-knot disease

Water deficit is one of the limiting factors of plant productions in arid and semi-arid areas. Many adaptive strategies such as accumulation of osmotic adjustments, phenolic compounds and antioxidant enzymes activity have been developed in plants for dealing with drought stress. The use of microorganisms, including probiotic bacteria, is a type of soil management that is effective in reducing the effects of stress. This experiment aimed to determine the effects of some probiotic bacterial strains on proline, sugar, total phenolic compounds (TPC), phenylalanine ammonia lyase (PAL), photosynthesis pigments and antioxidant activities of cucumber plants under drought stress. A completely randomized design was applied with a factorial arrangement of two factors: irrigation levels and bacteria strains with three replications. The results showed that proline, sugar, TPC, PAL and enzymes activity in control and inoculated plants were increased by increasing drought stresses. By contrast photosynthesis pigments significantly decreased under stress. The use of bacterial strains alleviate the harmful effect of stresses by an accumulation of proline, TPC, sugar, PAL activity and enzyme activity. The results also showed that inoculated plants had higher antioxidant activity compared to control plants under drought. It was found that the use of probiotic bacteria is an effective strategy to enhanced drought stress tolerance in plants.

Plant probiotic bacteria are a group of microorganisms that enhance plant growth and protect plants against many diseases by several mechanisms; they can also be used as biofertilizers.

In this study, the ability of Bacillus subtilis strains (VRU1 and BS-VRU) to produce siderophore, IAA, and some enzymes, such as cellulase, lipase, protease, as well as their potential biocontrol against Phytophthora drechsleri, the causal agent of crown and root rot in pistachios, were evaluated in vitro. In addition, the effects of these bacterial strains on growth parameters, such as fresh and dry weights of shoots and roots, plant height, as well as the biocontrol of P. drechsleri were investigated under greenhouse conditions.

According to the results of this study, two strains were able to produce siderophore, IAA, lipase, cellulas, and protease. Greenhouse results showed that both strains of B. subtilis increased growth parameters significantly in inoculated plants compared to the control. In addition, the results obtained showed that these bacterial strains decreased the mortality rate of pistachio seedlings, with the highest and lowest reductions having been 75% and 50% in VRU1 and BS-VRU, respectively.

According to the results, pistachio gummosis could be controlled by Bacillus subtillis bacteria. In addition, B. subtilis VRU1 and BS-VRU showed high efficacy in the suppression of diseases through several biocontrol mechanisms.

In this study, the effect of some plant probiotic bacteria were isolated from salty and dry areas were investigated in control the fungus agent pistachio gummosis disease and growth stimulating properties. 200 bacteria isolates were isolated from rhizosphere and non rhizosphere areas of pistachio trees and weeds in the margins of gardens in Kerman province. Thirty isolates were able to endure the used salt tolerant. The bacteria isolates were investigated at the hypersensitivity reaction (HR) test. Three of them were eliminated due to positive result of HR and the other were studied more as antagonist agents. In the early stage the biocontrol ability of these isolates against the fungus causing pistachio gummosis diseases such as Phytophthora drechsleri were surveied. For this purpose, inhibition zone test (antibiosis) was performed that antagonist isolates showed significant effect on P. drechsleri growth. In the secondary stage, The ability of isolates to produce some biocontrol metabolites including protease, antifungal volatile compounds and hydrogen cyanide were evaluated. Growth stimulating characteristics of these isolates incloding amount of siderophore and IAA production were measured. soluble ability of insoluble mineral phosphate was surveied, too. The results showed from 27 studied isolates for growth stimulating properties, %80 at least had one of the PGPR properties. %64 of the isolates were productive of siderophore, %80 productive of IAA, %45 having solving ability of insoluble mineral phosphate. The isolates C16, F47 and G11 as superior isolates of this study in vitro were successful in controlling the disease.

Crown and root rot of pistachio trees is a serious disease in pistachio orchards that is induced by Phytophthora species. Due to the harmful effects of chemical compounds on the environment and human health, great emphasis has been placed on the biocontrol of plant diseases, in recent years. Some plant growth promoting microorganisms, such asrhizobacteria (PGPR) and fungi (PGPF), suppress plant pathogens by various direct and indirect mechanisms, including colonization, antibiosis, production of lytic enzymes and volatile compounds (VOCs), as well as induced systemic resistance (ISR). From among beneficial microorganisms, Bacillus and Pseudomonas strains and Trichoderma species have been used as biocontrol agents in many studies, due to their strong biocontrol effects on a wide range of plant pathogens. In recent years, many studies have been done on the biological control of crown and root rot (gummosis disease) of pistachio trees. In the current study, the biocontrol efficacy of soil microorganisms antagonistic to Phytophthoracrown and root rot of pistachio trees has been evaluated.

Plant growth promoting rhizobacteria (PGPR) are widely used in protecting plants against pathogens in horticultural crops.

In the current study, the effects of two bacterial strains, i.e. Pseudomonas fluorescens VUPF5 and Bacillus subtilis Bs96 were evaluated on plant growth and antioxidant enzymatic activities, such as GPX, PPO, and PAL, either inoculated with Phytophthora drechsleri or alone, in two pistachio cultivars of Sarakhs and Badami-Rize-Zarand.

The two bacterial strains reduced the mortality rate of pistachio seedlings and increased growth parameters, such as dry and fresh weights of plants’ roots, shoots, and height. The enzymatic activities and levels of phenolic compounds increased in seedlings after inoculation with the two bacterial strains and P. drechsleri. The maximum enzymatic activities were observed on the 6 th day after co-inoculation with the bacterial strains and P. drechsleri.

Pseudomonas fluorescens VUPF5 resulted in the highest levels of enzymatic activities and phenolic compounds. The highest levels of enzymatic activities and phenol contents were found in Badami-Rize-Zarand cultivar, with a highest level of resistance to P. drechsleri.

In order to determine the most efficient chemical compound in fluctuation of plant defense enzymes level and causing resistance to Phytophthora drechsleri in two pistachio cultivars (Sarakhs and Badami-riz-Zarand), a factorial experiment was carried out based on complete randomized design (CRD) with chemical compounds (potassium phosphite, fosetyl-aluminium, potassium silicate, complex amino acid, and siderophore). The results indicated that chemicals used for this experiment were able to reduce the percentage of death in pistachio seedlings as plants treated with potassium phosphite and amino acid complex with 100% and fosetyl-aluminium with 25% had the most and the least effects in these reduction of disease incidence, respectively. These compounds increased plants height, roots, and shoot fresh and dry weights in comparison to the control and inoculated plants with P. drechsleri. The results indicated that chemical compounds used for this experiment were able to reduce the percentage of death in seedling. Plants treated with pottasium phosphite Chemical compounds also enhanced enzymatic levels and phenolic compound content, which phenomenon was more obvious in simultaneous inoculation with disease agent and lead to enhancing the peroxidase, poly phenol oxidase, phenylalanin aminolyase enzymatic level, and total phenolic compound content.

Using plant probiotic bacteria, which can induce systemic tolerance in plants, is one of the most important strategy to reduce the damage of drought stress in plants. In this study the effect of four fluorescent strains (T17-4, VUPF5, 428, CHA0) was investigated on resistance of two pistachio cultivars (Badami-Rize-Zarand and Sarakhs) against the drought stress. A completely randomized design was applied with a factorial arrangement at three replications in a greenhouse trial. In order to evaluate the effects of bacteria on reduction the effects of drought stress, some parameters such as prolin, soluble sugars, chlorophyll a, chlorophyll b, P, Zn, Fe content of shoot and root were measured. The results showed that drought stress increased the prolin and soluble sugars content in both inoculated and non-inoculated seedlings, although the content of prolin and soluble sugars in inoculated seedlings were higher than non-inoculated seedlings. The result also indicated that the drought stress reduces growth parameters, photosynthesis pigments and mineral element content in both cultivars under inoculated and non-inoculated conditions. The most reduction of these traits were recorded in non-inoculated seedlings. The cultivars of pistachio showed different responses to drought stress, so that sarakhs cultivar was recognized more sensitive to drought stress than badami-Rize-zarand cultivar.