تاثير سويه هاي Bacillus cereus بر آزاد سازي پتاسيم و آهن از كاني هاي ميكايي در محيط هاي آزمايشگاهي و ريزوسفر جو

چكيده انگليسي :

Effect of Bacillus cereus Strains on the Release of Potassium and Iron from Micaceous Minerals under Laboratory and Barely Rhizospheric Conditions Mohsen Soliemanzadeh m solymanzadeh@ag iut ac ir January 11 2014 Department of Soil Science Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiH Khademi hkhademi@cc iut ac irM Sepehri sepehri@cc iut ac irAbstract Microorganisms play an important role in providing nutrients for plants and also in soil development Microorganisms help the release of nutrients from soil minerals using different mechanisms This studywas conducted to investigate the effects of two strains of Bacillus cereus on potassium and iron releasefrom micaceous minerals under laboratory and rhizospheric conditions Under laboratory condition acompletely randomized design with factorial arrangement with three replications consisting of twominerals phlogopite and muscovite two strains of bacteria PTCC 1247 and PTCC 1665 and control no bacteria and eight time periods including 12 hours 1 2 4 8 16 32 and 64 days were used Themicaceous minerals were affected by strains of bacteria for different time periods Then the amount ofreleased potassium and iron soluble from minerals were measured by flame photometry and atomicabsorption spectrometery respectively The greenhouse experiment was run using a completelyrandomized design with factorial arrangement and three replications The treatments included fournutrient levels complete iron free potassium free and iron and potassium free two types of potassiumbearing minerals phlogopite and muscovite two strains of bacteria PTCC 1247 and PTCC 1665 andcontrol The pots were irrigated with four nutrient solutions during the growing season After 150 days shoot and root of plants were harvested and the amount of potassium and iron was measured Then claysize particles were separated and clay mineral analysis was carried out by XRD The results of thelaboratory experiment showed that the rate of potassium and iron release dependson the type of mineraland bacterial strain Strains PTCC 1665 released higher amount of potassium Up to 32 days potassiumreleaseincreased but decreased afterward At all the time periods the released potassium was higher inPTCC 1665 than PTCC 1247 and control However unexpected results indicated that release ofpotassium from phlogopite was less than muscovite Release of iron at the start of experiment 12h increased but decreased afterward and at the end of the experiment it increased again After 12h thehighest amount of iron was released from phlogopite and the amount of iron released from phlogopitewas higher than muscovite Results of greenhouse experiment showed that both strains of bacteriaincreased root and shoot dry weights However iron and potassium uptake increased under the treatmentof bacteria strains in rhizosphere Results of XRD analyses indicated that release of potassium and ironfrom interlayer and structure of phlogopite respectively led to hydroxyinterlayer vermiculate HIV formation Whereas no visible changes were observed in muscovite XRD patterns The presence ofbacteria in plant rhizosphere could release nutrients from soil minerals and lead to improve growth andyield of plants In conclusion the optimal use of useful type of bacteria could decrease chemical fertilizerapplication under greenhouse conditions Keywords Release of potassium and iron Bacillus cereus Muscovite Phlogopite

سليمان زاده، محسن

تاثير سويه هاي Bacillus cereus بر آزاد سازي پتاسيم و آهن از كاني هاي ميكايي در محيط هاي آزمايشگاهي و ريزوسفر جو

فلوگوپيت , موسكويت