Worldwide review of bacterial diseases of oaks (Quercus sp.) and their potential threat to trees in Central Europe

Abstract

The phenomenon of hhh Europe has been observed for over 100 years. In this time, many attempts have been made to describe this phenomenon considering biotic, abiotic and anthropogenic factors. Recently, an increasing intensity of bacterial tree diseases has been observed both in Europe and around the world. Moreover, climate change is contributing to an increase in the range of pathogens. The aim of this publication was to highlight the most important bacterial diseases occurring on oaks around the world, and to discuss the potential threat to native oaks occurring in Central Europe: English oak (Quercus robur L.) and sessile oak (Quercus petraea (Matt.) Liebl.). The main focus was on three diseases caused by different bacteria: bacterial leaf streak (caused by Xylella fastidiosa), acute oak decline (caused by Gibbsiella quercinecans, Rahnella victoriana and Brenneria goodwinii) and drippy nut disease (caused by Brenneria quercina—formerly Erwinia quercina). At present, these are the only known bacterial diseases that cause damage to oak stands. Information on each of the above-mentioned diseases is given in the review, ranging from their origin, importance, list of host plants and their potential threat to native oaks of Central Europe.

Dieback of small‐leaved lime trees (Tilia cordata Mill.) caused by Gibsiella quercinecans in urban areas in Poland

“…In addition, the pathogenicity tests carried out have shown that this bacterium is able to infect healthy lime tissue, causing changes that were previously found and described mainly in oaks. Until now, the presence of this bacterium was closely related to the phenomenon described as Acute Oak Dieback, in which it was responsible, together with B. goodwinii , R. victoriana and L. quercina , for canker lesions on oak trunks in many European countries (Tkaczyk, 2023). Similar symptoms were also observed on lime trees in the United Kingdom and the observations made at that time contributed to the description of a new bacterial species, Brenneria tiliae (Kile et al., 2022).…”

Xylella fastidiosa, Possible New Threat to Chestnut (Castanea sativa Mill.) in Italy

“…unknown); and Q. virginiana (subsp. unknown) [42]. As regards the genus Fagus (subfamily Fagoideae), in America the species Fagus crenata was reported as a symptomatic host of Xf (subsp.…”

The Role of Bacteria in Acute Oak Decline in South-West Poland

“…Among the biotic factors causing tree mortality, pathogenic bacteria responsible for the phenomenon of Acute Oak Decline have been increasingly mentioned in recent years [12,13]. Trees affected by Acute Oak Decline show abundant discharge between bark cracks.…”

“…Recent studies have identified Gibbsiella quercinecans, Rahnella victoriana, and Brenneria goodwinii as the main causes of AOD in the UK [10,14]. These bacteria can be spread by wind or rain [12], but the most common route of transmission is insects. The presence of bacteria has been repeatedly found in the galleries of the larvae of Agrilus biguttatus [10,13].…”