Molekularna karakterizacija kvržičnih bakterija izoliranih iz tla s poplavnjenog područja županjske Posavine

master's thesis

• Author: Valentina Knok
• Mentor: Mihaela Blažinkov (mentor)
• Committee member: Mihaela Blažinkov (predsjednik povjerenstva)
• Committee member: Sanja Sikora (član povjerenstva)
• Committee member: Ana Pospišil (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Microbiology); Zagreb
• Defense date and country: 2016-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

U svijetu kao i u Hrvatskoj se posljednjih godina sve više bilježe ekstremni vremenski događaji kao posljedice klimatskih promjena. Takve promjene imaju velik utjecaj na prirodne sustave, a tako i poljoprivrednu djelatnost koja izravno ovisi o klimatskim prilikama te je od iznimne važnosti postala održiva poljoprivreda koja teži smanjenju negativnih posljedica na okoliš. Biološka fiksacija dušika je prirodni proces gdje se putem simbiotskog odnosa kvržičnih bakterija i većina leguminoza slobodni atmosferski dušik pretvara u organski oblik dostupan biljci. Nadalje, selekcijom sojeva kvržičnih bakterija koji su pokazali učinkovitost i u nepovoljnim klimatskim uvjetima bi omogućilo iskorištavanje prirodnog procesa biološke fiksacije. Cilj ovog rada je izolacija i karakterizacija kvržičnih bakterija koje su izolirane iz poplavljenih područja županjske Posavine. Molekularne metode korištene za genetsku karakterizaciju izoliranih bakterija su 16S rDNA PCR - RFLP, RAPD i rep - PCR metoda. Na osnovi rezultata 16S rDNA PCR – RFLP metode utvrđeno je da većina izolata pripada vrsti Bradyrhizobium japonicum. Primjenom RAPD i rep – PCR metode utvrđena je velika genetska varijabilnost između ispitivanih sojeva. Ipak, obje metode su potvrdile da najveću sličnost između sojeva imaju sojevi izoliranih s lokacije Rajevo selo.

Abstract (english)

During the last several years, the world as well as Croatia, have been affected by the extreme weather events as a result of climate change. Such changes have immense effect on human and natural ecosystems, more precisely on agriculture, which is directly dependant on changes concerning the climate. It has become of crucial importance to follow the inputs of sustainable agriculture and reduce the negative consequences on the environment. One of such sustainable processes in the nature is biological nitrogen fixation, where rhizobia form a symbiotic relationship with most legumes, which results in converting the atmospheric nitrogen to organic forms which can be used by plants. Futhermore, the selection of rhizobial strains that have demonstrated effectiveness even in the unfavourable conditions would enable the further exploatation of this natural process even in the areas affected by extreme environmental conditions. The aim of this study was to isolate and identify rhizobia that were obtained from flooded areas of županjska Posavina. Molecular methods used for the genetic characterization of isolated bacteria were 16S rDNA PCR – RFLP, RAPD and rep – PCR methods. The results based on 16S rDNA PCR – RFLP method showed that majority of the isolates could be regarded as Bradyrhizobium japonicum. RAPD and rep – PCR methods showed a considerable level of genetic diversity among isolated strains, but also proved that the greatest similarity between the strains are strains isolated from Rajevo Selo.

• Keywords: klimatske promjene; simbiozna fiksacija dušika; kvržične bakterije; genetska varijabilnost; 16S rDNA PCR – RFLP; RAPD; rep – PCR
• Keywords (english): climate changes; symbiotic nitrogen fixation; rhizobia; genetic diversity; 16S rDNA PCR – RFLP; RAPD; rep – PCR
• Language: croatian
• URN:NBN: urn:nbn:hr:204:089423
• Study programme: Title: Plant Sciences; Study programme type: university; Study level: graduate; Academic / professional title: magistar / magistra inženjer/inženjerka biljnih znanosti (magistar / magistra inženjer/inženjerka biljnih znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2016-10-18 06:51:19