Prevalence patogenů asociovaných se syndromem předčasného odumírání meruněk v komerčních výsadbách v České republice

Abstract

Apoplexy of apricots represents a long-lasting problem for Czech apricots growers. It is assumed that apricot tree dieback is caused by a complex of biotic and abiotic factors. Pathogenic bacteria, fungi and viruses are considered a biotic factor that plays a key role in apricot withering. To evaluate health status in commercial apricot orchards, a study was conducted between 2019 and 2021. Within three years, 16 localities were monitored in four most important apricot planting areas in the Czech Republic. In total, 246 samples were collected that were analyzed by real-time PCR for the presence of the following pathogens: ˈCandidatus Phytoplasma prunorumˈ, Pseudomonas syringae, Cytospora spp., Erwinia amylovora, plum pox virus (PPV), prune dwarf virus (PDV), prunus necrotic ringspot virus (PNRSV), and little cherry virus 1 and 2 (LChV 1 and LChV 2). Our results have shown that ˈCandidatus Phytoplasma prunorumˈ is highly prevalent (70.6 % of symptomatic samples), and confirmed a primary role of phytoplasmas in withering of apricots. Pseudomonas syringae bacterium was detected in 2/3 of samples. Cytospora spp. were another pathogens found in apricot dying trees in nearly 25 % of symptomatic trees. PPV was detected in older orchards, but its presence was not associated with apricot apoplexy, since it was also found in asymptomatic samples with about the same frequency. PDV and PNRSV were found only sporadically, and likely do not play a major role in apricots dieback. Alarmingly, LChV 1 was observed in one young orchard in 80 % of samples. LChV 2 and Erwinia amylovora have not been detected.

Keywords

• apricots
• pcr diagnostics
• european stone fruit yellows
• esfy