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Showing 7 results for baghaee


Volume 3, Issue 1 (3-2014)
Abstract

In this study two Bacillus pumilus including ToIrFT- KC806241 and ToIrMA-KC806242 were obtained from tomato fields and characterized based on phenotypic and molecular properties. Their possibility to reduce root knot disease of tomato caused by Meloidogyne javanica was evaluated. The experiments were done in lab and under pot conditions. Application of the ToIr-MA against M. javanica reduced the number of galls and eggs. Preliminary results indicated that the ToIr-MA has an ability to produce proteolytic enzymes in lab conditions. It seems that the bacterial culture filtrates can suppress egg hatching and increase juvenile's mortality, but the role of these metabolites in disease suppression needs to be investigated. Significant enhancement in root and shoot length (33%) and dry root and shoot weight (64 and 67%) was also recorded over usage of strain ToIr-MA in comparison to untreated controls. Additionally, survival of bacterial strains in rhizosphere and increases in population density were seen using root colonization assay. To our knowledge, this is the first time that such B. pumilus strain with nematicidal activity against M. javanica has been reported in Iran which may suggest to manage disease and change microbial population dynamics in the rhizosphere.  

Volume 3, Issue 3 (9-2014)
Abstract

Samples of leaf, twig and fruit from ‘Mexican’ lime (Citrus aurantifolia) and grapefruit (Citrus paradisi) with symptoms of bacterial canker were collected from different provinces throughout Iran during spring and summers of 2010 and 2011. Yellow, gram-negative colonies were isolated from infected tissue samples. Results of pathogenicity assays indicated that some isolates incited tissue hyperplasia, hypertrophy and raised callus-like lesions typical of canker in hosts while other isolates stimulated flat necrotic and water-soaked lesions on leaves. Candidate samples of each group were identified according to morphological and physiological characteristics. Detections were also made using specific primers and partial sequencing of 16SrDNA for Pantoea group and gyrB for Xanthomonas group. Results showed that one group was characterized as the typical Xanthomonas citri subsp. citri strain while the other group containing most of the isolates was identified as Pantoea agglomerans. Samplings done frequently in different seasons revealed the presence of high populations of P. agglomerans with bacterial canker, especially in warmer and drier regions. These bacteria were able to incite canker-like symptoms on grapefruit seedlings and could be reisolated after two months.

Volume 13, Issue 3 (12-2024)
Abstract

Among rhizobacteria, plant-beneficial effects of Pseudomonas bacteria are known in agricultural ecosystems. Screening of fluorescent pseudomonad isolates obtained from potato rhizosphere led to selecting five bio-reagents capable of controlling soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum (Pcc) (JX029052) in plate assay, on intact potato tubers and under storage challenges using preventative and curative applications. The biocontrol features related to the tested rhizospheric bacteria were also evaluated. According to phenotypic tests, the representative antagonistic strains belong to the fluorescent pseudomonads group and are placed in the P. protegens cluster based on 16S rRNA gene sequencing. Strains IrPs8 and IrPs18 are potent to produce siderophore, cyanide hydrogen, and protease, form strong biofilm and carry phl, plt and prn genes on their genomes corresponding to 2, 4-diacetylphloroglucinol, pyoluteorin and pyrrolnitrin, respectively. Treated tubers inoculated with IrPs8 and IrPs18 showed a reduction in the soft rot-inducing potency of Pcc by 63.4 and 65.5% in preventative and by 57.8 and 58.3% in curative tests, respectively, under storage conditions that confirmed the in vivo results. This study highlights the potential of rhizospheric P. protegens strains as beneficial bacteria that can be suggested as preservative coatings for potato tubers under storage conditions.

 

Volume 19, Issue 3 (5-2017)
Abstract

In the current study, molecular typing of 50 Erwinia amylovora strains related to different regions in Iran was evaluated using multi-locus sequence analysis and variable number of tandem repeats. In the first assay, phylogenetic tree based on partial sequences of recombinase A, sigma factor S and a heat shock protein GroEL showed significant identity in studied gene sequences. A single nucleotide variation in groEL was determined in IrGh59 strain related to Crataegus spp. from Ghazvin Province. In VNTR analysis, the same fingerprinting profile similar to E. amylovora reference strain ATCC49946 was yielded for tested strains except NBQ1 and MQ1 which may reflect a unique contaminating source for this disease in Iran. In addition, the honey-bee movements with respect to blossom season probably have a considerable role in fire blight unique dispersal in our area. The NBQ1 and MQ1 strains generated different VNTR profiles, isolated from cultivars NeishabourandEsfehan of Cydonia oblonga plant, respectively. No definite assessment can be expressed in this case. However, possible entry of other infection mass from neighboring countries should be determined. Overall, VNTR profile analyses are recommended as a tool to evaluate genetic differences in E. amylovora populations. In addition, employing more strains from different known sources could be assistance to achieve more accurate results about E. amylovora genetic variation and also fire blight distribution patterns.

Volume 21, Issue 4 (7-2019)
Abstract

In the current study, the phenotypic and molecular properties of twenty-five strains obtained from cankerous tissues or leaf necrotic lesions of different stone fruits were evaluated in north-east of Iran . All strains studied were identified as Xanthomonas arboricola pv. pruni (Xap) based on phenotypic assays and confirmed by means of specific PCR at species and pathovar levels. All obtained strains were pathogenic under artificial inoculation and exhibited brittle necrotic spots on plum leaves of cultivar Santa Rosa under lab conditions. Then, the pathogenic Xap strains were subjected to molecular assays. In a phylogenetic tree constructed with gyrB sequences, no polymorphism was observed in this gene and Iranian Xap strains were clustered with the reference one in a separate group. The ERIC, BOX and REP primer sets generated reproducible genomic PCR profiles in tested strains and, based on combined data for all primers, a low genetic diversity among Xap strains was revealed. In order to achieve results that are more accurate, application of Xap strains from all geographical regions of Iran will be needed to prove little polymorphism observed in Xap population. The current contribution is the first report of molecular homogeneity of Xap strains that were collected from northeastern Iran.
 

Volume 24, Issue 1 (Spring 2020)
Abstract

Introduction
 
In recent years, the world has been witnessing climate change which is mostly due to socio-economic activities of man and in turn producing greenhouse gas emissions. These actions have been led to global warming, melting of glaciers and extreme variability of weather indicators such as rainfall and temperature. These changes in our country have also shown itself in phenomena like snowfall shortage, devastating floods and storms, terrible and out-of-season storms, and unprecedented summer heat. These Climate fluctuations have had significant effects on different sub-sectors of the economy, especially agriculture, and the phenomenon of climate change in agriculture has shown itself at the first step in different forms of drought. Increasing farmers' resilience and adaptability to climate change are the major strategies that many countries have taken into account to face and confront the negative consequences of drought. One of the provinces that are facing drought phenomenon in Isfahan Province. For example, conflicts among farmers on water shortages and water transfers from this province to the neighboring provinces and crisis in Zayandeh Rood River are just some proof showing the severity of the situation.
 
 
Methodology
Based on the present study, the SWOT Matrix was used to identify the strengths, weaknesses, opportunities, and threats of small-scale farmers' adaptation to drought conditions in Isfahan province. Therefore, appropriate strategies were developed and proposed to achieve this objective. The statistical population of this research consisted of 110 experts working in the field of drought management in Isfahan province out of which, 88 people were selected on the basis of the Krejcie & Morgan table. The main instrument of this study was a questionnaire whose content validity was confirmed by the opinions of an expert panel in the Department of Agricultural Development and Management at the University of Tehran and its reliability was confirmed by Cronbach's alpha coefficients. In order to find appropriate strategies, the TOWS matrix was developed and used in this study. This method integrates scientific and theoretical opinions with application remarks. This method is innovative and provides lights to workable strategies based on a reasonable and appropriate framework.
 
Result and Discussion
Based on the results of study, the most important opportunities for the adaptation of small-scale farmers to drought condition were the "implementing rainwater harvesting programs", "improving urban potable and green-space water management " and "national support for all strategies related to adaptability to climate change in formulating appropriate policies and regulations" It is while the most important threats found to be "weak governmental administrative works for recognition and management of climate change consequences", "insufficient supportive credit for drought management" and "insufficient attention by government to extension education programs related to drought management", In terms of the internal environment, the most important strength was found to be "Increasing farmers assets and their productive power, “cooperation of farmers to manage drought" and "Strengthening farmers Organizations ". Besides, the most important weaknesses were identified as “the low willingness of farmers to apply technologies for reducing greenhouse gases emission", "high cost of irrigation equipment to reduce water consumption" and "decreasing farms resilience towards climate change".
 
Conclusion
 Drought covers about 80% of Isfahan province and 22.5% of the province has been faced with severe drought. A survey of drought conditions over the past years indicates that most parts of Isfahan province are affected by drought. The drought has had many detrimental effects on different parts of the province, including agriculture, industry, services, the environment, public and cultural green spaces. Desertification, air pollution, and dust generation, relative humidity reduction, soil moisture depletion, rangeland wildfire, salinization and depletion of groundwater resources, damage to historic structures are some examples of the negative consequences drought in Isfahan province. In addition, the direct effects of water scarcity on agriculture and other socio-economic sectors are evident.  Outbreaks of pests and plant and animal diseases, increased agricultural migration to cities, loss of productive livestock, reduced aquaculture, and the crisis of access to potable water and reduction of farm productivity in rural areas have been observed and reported as some of the effects of drought. Accordingly, the present study was conducted to find appropriate coping strategies. However, in analyzing the strategic space, the results showed that the most efficient and adaptive strategies in the Jihad Agriculture Organization of Isfahan Province are placed in the ST area. Moreover, using a TOWS matrix, some other agricultural adaptive strategies were formulated to be used in the drought conditions of the province. SO strategies recommend operations such as Diversification of Resistant Crops,   Improving interaction between actors in the agricultural production chain and Proper management of floods through water harvesting projects. Under ST strategies operations such as paying attention to support programs and subsidizing drought management among farmers, Support diversification of livelihood investments for agriculture in times of drought crisis and strict monitoring of groundwater harvesting through the strengthening of aquifers are suggested. WO strategies focus on operations like Using modern irrigation equipment in agriculture through government support for water management projects, Improving specialized drought information for farmers by improving the efficiency of technical-engineering companies in providing services to farmers and Reduce farmers' migration by supporting livelihood adaptation strategies in government programs and projects. WT strategies also place its attention on operations such as Convergence of public and private sectors in implementing drought management programs and providing specialized information to farmers, Change the cropping pattern with the aim of developing drought-resistant varieties,  Defining a clear role for farmers in drought management in agricultural development programs.
 


Volume 25, Issue 6 (11-2023)
Abstract

In the present study, bacterial endophytes were obtained from weeds of potato fields. Their antagonistic activity was screened against potato storage pathogen, Pectobacterium carotovorum subsp. carotovorum (Pcc) (JX029052), in the maceration assay. An endophytic strain, PC-2B was isolated from Convolvulus arvensis L. as a dominant weed of potato fields. In vivo application of this strain led to 58.8% reduction in tuber decay. This motile strain that can produce amylase was identified as Pantoea sp. using phenotypic features and 16S rRNA sequencing. Following PC-2B treatment, 56.7% Reduction in Disease Incidence (RDI) was obtained in preventative and 52% in curative challenges under semi-practical storage trails. Anti-Pcc bioactive compounds of Pantoea sp. was extracted and identified based on H NMR and FT-IR techniques. Two peptide antibiotics including Pantocin A and B with inhibitory effect against Pcc were characterized. These results might indicate that the tested Pantoea strain could be a promising candidate to protect potato tubers against soft rot disease caused by Pcc. However, large-scale complementary trials have to be conducted to validate these results before any recommendations.

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