Naslov
‘Candidatus Phytoplasma mali’ – a molecular characterization of an emerging phytoplasma species in Croatia

Autori
Plavec, Jelena ; Križanac, Ivana ; Budinšćak, Željko ; Ivić, Dario ; Škorić, Dijana ; Šeruga Musić, Martina

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, ostalo

Izvornik
XVIII. International Plant Protection Congress (IPPC) 2015 Abstract book / - Berlin, 2015, 35-35

Skup
XVIII. International Plant Protection Congress (IPPC)

Mjesto i datum
Berlin, Njemačka, 24.08.2015. - 27.08.2015

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
AP; plant disease; phytoplasma; phylogeny; MLST

Sažetak
Introduction A survey on the presence and diversity of phytoplasmas infecting fruit trees and their vectors in Croatia has been conducted since 2002. Although the presence of ‘Candidatus Phytoplasma pyri’ and ‘Ca. P. solani’ was sporadically associated with symptomatic apples, there was no direct evidence of the ‘Ca. P. mali’, the main etiological agent of Apple proliferation disease (AP) in neither plant nor insect vector samples. Objectives The aim of this study was to reassess the presence of the ‘Ca. P. mali’ in Croatian orchards as well as to investigate the variability of detected genotypes by multilocus sequence typing (MLST) analysis. Materials and Methods Throughout 2011 and 2012, orchards from all fruit growing regions of Croatia were surveyed for AP symptoms and nearly 70 samples of different apple varieties were collected. Psyllid samples were collected in 2012 from two selected orchards in the north-western part of the country. Total nucleic acids were extracted and PCR/RFLP analysis of phytoplasma 16S rDNA was performed by using P1/P7 primers in a direct PCR assays followed by nested PCR using R16(X) F1/R1 primers. Amplicons from nested PCR were digested with RsaI and SspI to determine the affiliation to the ‘Ca. P. mali’ species. To confirm the results, real-time PCR amplifying 16S rDNA was also performed. Furthermore, pnp, secY, imp and aceF genes were amplified using newly designed primers. All obtained amplicons were sequenced and phylogenetic analyses were performed. Results For the first time, in 2011, the occurrence of ‘Ca. P. mali’ was detected in samples collected from seven locations in continental as well as Adriatic Croatian regions while the survey in the following year revealed one additional location with the ‘Ca. P. mali’ occurrence. The analysis of psyllid vectors revealed one positive finding of ‘Ca. P. mali’ in female specimen of Cacopsylla picta from an orchard in the north-western Croatia. PCR/RFLP results were consistent with the results obtained by real-time PCR. Phylogenetic analysis of pnp, secY, imp and aceF gene sequences revealed considerable diversity among Croatian AP strains with pnp being the most variable. Conclusions This is the first molecular detection as well as the MLST analysis and genotyping study of ‘Ca. P. mali’ in Croatia, from both apple and insect vector species.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA