Molekularna epidemiologija i multigenska tipizacija bakterije ‘Candidatus Phytoplasma mali’ u Hrvatskoj

doctoral thesis

• Title (english): Molecular epidemiology and multigene typing of ‘Candidatus Phytoplasma mali’ in Croatia
• Author: Ivana Križanac
• Mentor: Martina Šeruga Musić (mentor)
• Committee member: Dijana Škorić (predsjednik povjerenstva)
• Committee member: Mirna Ćurković Perica (član povjerenstva)
• Committee member: Dušica Vujaklija (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; Zagreb
• Defense date and country: 2017, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Biology
• Universal decimal classification (UDC): 57 - Biological sciences. Physical anthropology. Biodiversity

Abstract

Fitoplazme ('Candidatus Phytoplasma') su unutarstanični, pleomorfni biljni patogeni iz razreda Mollicutes koji tijekom životnog ciklusa koloniziraju biljke i kukce - vektore. Proliferacija jabuke (Apple Proliferation, AP) jedna je od važnijih fitoplazmoza prisutnih u većini europskih zemalja. Uzrokuje ekonomske gubitke u proizvodnji i uzgoju jabuke. Ovim istraživanjem i multigenskom analizom sojeva uzročnika bolesti 'Ca. P. mali' (2011. – 2014. i 2016.)obuhvaćena su značajna područja uzgoja jabuke u Hrvatskoj. 'Ca. P. mali' detektirana je i identificirana metodama PCR i real-time PCR baziranim na umnažanju gena za 16S rRNA. Za karakterizaciju sojeva primijenjena je metoda multigenske tipizacije za koju su odabrana 4 ciljna gena različite razine konzerviranosti i evolucije: aceF, pnp, imp i secY. U odnosu na do sada iz literature poznate genotipove, za svaki od gena je redom identificirano tri, dva, sedam te pet novih genotipova. Najveća raznolikost genotipova prisutna je na malom području Međimurske županije. Na osnovi rezultata opisano je 20 alelnih profila od kojih je dominantan ST1 (A13-P10-S12-I21). Po prvi puta uopće tipizirani su i sojevi izolirani iz kukca – vektora vrste Cacopsylla picta te su ovim istraživanjem značajno prošireni dosadašnji rezultati multigenske tipizacije 'Ca. P. mali' u Europi. Stečena saznanja pridonose razumijevanju epidemiologije i temelj su za daljnja istraživanja te poboljšanje mjera kontrole i sprečavanja širenja bolesti u Hrvatskoj.

Abstract (english)

Phytoplasmas ('Candidatus Phytoplasma') are intracellular pleomorphic plant pathogens belonging to the class Mollicutes. Their life cycle includes colonisation of both plant hosts and insect vectors. Apple proliferation (AP) is present in many European countries. It is one of the most important phytoplasmoses causing significant economic loses in apple production. Causal agent, 'Ca. P. mali', was identified in the scope of this survey (2011 – 2014 and 2016) using PCR and real-time PCR based on amplification of 16S rRNA gene. In multilocus sequence typing (MLST), variability of four selected genetic markers differing in level of conservation and evolution (aceF, pnp, imp and secY) was studied. In addition to previously described and published genotypes, new ones were discerned for each genetic marker: 3 for aceF, 2 for pnp, 7 for imp and 5 for secY gene. Overall, 20 different sequence types (ST) were revealed. Based on the current results, the core sequence type ST1 (A13-P10-S12-I21) can be proposed. This is the first extensive research and multigene typing performed on 'Ca. P. mali' isolates in Croatia, as well as the first typed isolate from an insect vector host, Cacopsylla picta. Obtained results revealed considerable genetic diversity of epidemiological relevance limited to only one part of the country, Međimurje region. Characterization represents a good starting point for improvement of measures for preventing and control of the disease and further research.

• Keywords: AP; MLST; molekularni markeri; genska varijabilnost; alelni profil; ST
• Keywords (english): apple proliferation; MLST; molecular markers; genotype; genetic variability; sequence type; ST
• Language: croatian
• URN:NBN: urn:nbn:hr:217:393944
• Study programme: Title: Biology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija (doktor/doktorica znanosti, područje prirodnih znanosti, polje biologija)
• Type of resource: Text
• Extent: 117 str.
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-11-02 11:33:50