Title Antifungalni učinak entomopatogene gljive Beauveria bassiana na fitopatogenu gljivu Botrytis cinerea Title (english) Antifungal effect of the entomopathogenic fungi Beauveria bassiana on the phytopathogenic fungi Botrytis cinerea Author Anton Mihovilović Mentor Katarina Martinko (mentor)Committee member Katarina Martinko (predsjednik povjerenstva)Committee member Ivan Juran (član povjerenstva)Committee member Valentina Šoštarčić (član povjerenstva)Granter University of Zagreb Defense date and country 2023-09-18, Croatia Scientific / art field, BIOTECHNICAL SCIENCES Abstract Primjena antagonističkih mikroorganizama u supresiji fitopatogenih gljiva predstavlja supremeni pristup biološke borbe, a zbog značajnih beneficijskih učinaka, antagonistički mikroorganizmi se sve više istražuju. Kako bi se smanjila uporaba agrokemikalija, otkrivanje antagonističkih mikroorganizama i njihovih mehanizama supresije patogena, neophodni su u modernoj biljnoj proizvodnji.
Nekrotrofna gljiva Botrytis cinerea poznata kao uzročnik sive plijesni, dovodi do značajnih globalnih gubitaka prinosa i kvalitete proizvodnje u polju i skladištu nakon berbe. Zbog značajnog arsenala toksina kojima vrši patogenezu i velike genetske varijabilnosti, ova gljiva se smatra patogenom visokog rizika za razvoj otpornosti na fungicide zbog čega je primjena antagonističkih mikroorganizama u njenom suzbijanju obećavajuća strategija. Među antagonističkim mikroorganizmima biološke borbe spominje se i entomopatogena gljiva Beauveria bassiana, za koju se smatra da posjeduje i antagonistička svojstva u suzbijanju fitopatogenih gljiva zbog širokog spektra sekundarnih metabolita koje proizvodi. Radi što veće učinkovitosti antagonističkih gljiva u poljskim uvjetima, u novijim laboratorijskim istraživanjima posebna pažnja se pridaje istraživanju antagonističkih mehanizama u optimalnim uvjetima za njihov rast i razvoj koji variraju ovisno o izolatima.
Temeljem navedenog, u radu je testiran antifugalni učinak gljive B. bassiana na fitopatogenu vrstu B. cinerea u uvjetima in vitro metodom dvojnih kultura i testiranjem produkcije volatila na standardnoj PDA podlozi s dvije različite pH vrijednosti (pH= 5,6 i 7,2).
Rezultati testova dvojnih kultura i testiranja produkcije volatila su potvrdili da je antagonistički učinak gljive B. bassiana značajno viši na supstratu neutralne pH vrijednosti (pH=7,2) gdje je inhibicija patogena B. cinerea iznosila 35,9 % tj. 37,5 % što je postignuto različitim mehanizmima borbe. Na supstratu umjereno kiselog pH (pH= 5,6) postignut je postotak inhibicije oko 8 (4,4 %) tj. 3 (12,5 %) puta manji u odnosu na inhibiciju postignutu na supstratu neutrale pH vrijednosti. Mikroskopskom analizom potvrđeni su mehanizmi inhibicije antagonističke vrste B. bassiana (mikoparazitizam i antibioza), značajan na supstratu neutralne pH vrijednosti te deformacije i promjene na mikrostrukturama patogene gljive B. cinerea. Sukladno dobivenim rezultatima, izolat entomopatogene gljive B. bassiana ima značajan antagonistički potencijal u suzbijanju uzročnika sive plijesni u laboratorijskim uvjetima što je polazišna točka za daljnja istraživanja u uvjetima in vivo.
Abstract (english) The use of antagonistic microorganisms in the suppression of phytopathogenic fungus represents the ultimate approach to biological control, and because of their significant beneficial effects, antagonistic microorganisms are increasingly being researched. In order to reduce the use of agrochemicals, the discovery of antagonistic microorganisms and their pathogen supressive mechanisms are necessary in modern plant production.
The necrotroph fungus Botrytis cinerea known as the causative agent of gray mold, leads to significant global losses of yield and production quality in the field and in post-harvest storage. Due to the significant arsenal of toxins used in pathogenesis and great genetic variability, this fungus is considered a pathogen of high risk for the development of fungicide resistance, which is why the use of antagonistic microorganisms in pathogen suppression is a promising strategy. Among the antagonistic microorganisms of biological control, the entomopathogenic fungus Beauveria bassiana is mentioned, which is considered to have antagonistic properties in controlling phytopathogens due to the wide range of secondary metabolites. In order to maximize the effectiveness of antagonistic fungi in field conditions, in recent laboratory studies, special attention is paid to researching the antagonistic mechanisms of fungi under optimal conditions for their growth and development which vary depending on the isolates of the same species. Based on the above, the antifugal effect of the fungus B. bassiana on the phytopathogen B. cinerea was tested in vitro using the dual cultures method and testing the production of volatiles on a standard PDA substrate with two different pH values (pH= 5.6 and 7.2). The results of dual culture tests and volatile production testing confirmed that the antagonistic effect of the fungus B. bassiana is significantly higher on a neutral pH substrate (pH=7.2), where the inhibition of the B. cinerea was 35.9 %, i.e. 37.5 % which was achieved by different antagonistic mechanisms. On the substrate with a moderately acidic pH (pH= 5.6), the percentage of inhibition achieved was about 8 (4.4 %), i.e. 3 (12.5 %) times lower compared to the inhibition achieved on the substrate with a neutral pH value. Microscopic analysis confirmed inhibition mechanisms (mycoparasitism and antibiosis), more significant on a neutral pH substrate by the antagonistic species B. bassiana, and deformations and changes in the microstructures of the pathogen B. cinerea. According to the obtained results, the isolate of entomopathogenic fungus B. bassiana has a significant antagonistic potential in suppressing the causative agent of gray mold in laboratory conditions, which is the starting point for further research in vivo.
Keywords
antagonizam
antibioza
Beauveria bassiana
Botryts cinerea
mikoparazitizam
inhibicija.
Keywords (english)
antagonism
antibiosis
Beauveria bassiana
Botrytis cinerea
mycoparasitism
inhibition.
Language croatian URN:NBN urn:nbn:hr:204:606638 Study programme Title: Plant Protection Type of resource Text File origin Born digital Access conditions Access restricted to students and staff of home institution Terms of use Created on 2024-09-25 11:59:54
