Ekološko-biohemijska proučavanja varijabilnosti autohtonih vrsta gljiva iz roda Trichoderma u različitim tipovima zemljišta

Abstract

Gljive iz roda Trichoderma spp. su kosmopolitske filamentozne gljive koje se pojavljuju kao dominantne komponente zemljišnog ekosistema. Ekološka i biološka uloga ovih gljiva je veoma raznovrsna. Kao endofitni simbionti biljaka imaju primenu u kontroli biljnih bolesti čime pospešuju biljni rast i prinos. Takođe, poznata je i njihova sposobnost da indukuju otpornost kod biljaka koje su izložene biotičkom ili abiotičkom stresu. Pored važne primene u poljoprivredi one nalaze primenu i u različitim granama industrije jer proizvode mnogobrojne enzime i metabolite. Obzirom da su mnoge vrste u okviru ovog roda ne mogu razlikovati na morfološkom nivou, neophodna je njihova identifikacja na molekularnom nivou. Cilj ove teze bio je utvrđivanje najvažnijih faktora koji utiču na varijabilnost roda Trichoderma u različitim tipovima zemljišta. Molekularna identifikacija gljiva roda Trichoderma, izolovanih iz različitih tipova zemljišta (rendzina, sirozem na lesu, ritska crnica, fluvisol, ranker, gajnjača, černozem sa različitim podtipovima i smonica) i iz rizosfere različitih biljnih kultura urađena je analizom sekvenci ITS i TEF1-α gena. Uzorci zemljišta ispitani su u funkciji fizičko-hemijskih i mikrobioloških karakteristika, kao i sadržaja ukupnih i lakopristupačnih metala (Cr, Co, Ni, Cu, Zn, Cd, Pb i Mn). U cilju ispitivanja primene ovih gljiva kao antagonista fitopatogenih mikroorganizama, testirani su odabrani izolati prema Fusarium solani species complex (FSSC), Alternaria alternata i Phoma cucurbitacearum. Enzimska karakterizacija izolata odabranih za test antagonizma, urađena je semikvantitativnim testom API-ZYM. Kako bi se ispitao efekat ovih gljiva i na abiotski stres izazvan povećanim sadržajem metala u zemljištu, između ostalih, odabrani su izolati koji su identifikovani iz zemljišta u kojima je određena povećana koncentracija metala, bakra(II) i nikla(II). Na osnovu in vitro testa, gajenjem izolata na povećanim koncentracijama bakra(II) i nikla(II), odabran je izolat, koji je pokazao najveću tolerantnost i primenjen je u ispitivanju uticaja na biljke paradajza gajene u vodnom deficitu...

Fungi of the genus Trichoderma spp. are cosmopolitan species present in different ecosystems. with important ecological and biological roles.. Beneficial effects of this fungi are responsible for their use in various fields of biotechnology and agriculture. As plant endophytes they are involved in control of plant deseases. They are known to induce plant tolerance to various biotic and abiotic stresses. Known to produce different enzymes, they can be used in preparations of commercial products, such as biopesticides. However, for their adequate use and application their identification on the molecular level is of great importance. The aim of this thesis was to investigate the most important factors that influence Trichoderma variabilty in different soil types. Molecular identification of Trichoderma spp. from different soil types (Rendzic Leptosol, Regosol (Calcaric, Arenic), Calcic Gleysol, Fluvisol, Dystric Leptosol, Eutric Cambisol, Chernozem on loess terrace Chernozem (Arenic) and Vertisol) and plant rhizosphere of different crops was done based on their ITS and TEF1-α sequences. Variability was investigated in function of physical, chemical, microbiological properties of the soil, as well as total and extractable metal (Cr, Co, Ni, Cu, Zn, Cd, Pb and Mn) content in the soil. In order to examine the application of these fungi as antagonists of phytopathogens, selected strains of Trichoderma species were tested against Fusarium solani species complex (FSSC), Alternaria alternata and Phoma cucurbitacearum. The enzyme characterization of selected strains was performed with semiquantitative test API-ZYM. Furthermore, the selected strains were tested for tolerance to various concentrations of copper and nickel. The strain T. brevicompactum SZMC 22661 which showed the best tolerance to metals was applied in the examination of drought effect on tomato plants...