New host species for Chalara fraxinea

The susceptibility of Asian, European and North American Fraxinus species to the ash dieback pathogen Hymenoscyphus fraxineus reflects their phylogenetic history

“…All tested species except F. profunda developed relatively long lesions in the direct stem inoculation experiment (short in F. profunda), supported pathogen sporulation and showed generally high levels of pathogen DNA in leaf tissues. Other studies have similarly reported moderate susceptibility to ash dieback in species from section Melioides (Drenkhan and Hanso 2010;Gross and Sieber 2016;Kowalski et al 2015). The moderate disease susceptibility of North American ash species provides further support for the presence of an ancient phylogenetic signal in terms of pathogen host range.…”

“…These data are consistent with field and park observations, which indicate that F. excelsior (Kowalski 2006), F. angustifolia s.l. (Drenkhan et al 2015;Kirisits et al 2010) and F. nigra (Drenkhan and Hanso 2010) are more susceptible to ash dieback than F. ornus (Kirisits and Schwanda 2015). The North American specimen of F. quadrangulata (section Dipetalae) was the fourth species highly affected by ash dieback in the arboretum and consistently also supported a high production of pathogen apothecia.…”

“…Current evidence indicates that H. fraxineus originates from Asia, where it is associated with local Fraxinus species, Fraxinus mandshurica and F. chinensis (Cleary et al 2016;Gross et al 2014a;Zhao et al 2013;Zheng and Zhuang 2014). Observations from a botanical garden in Estonia (Drenkhan and Hanso 2010) and from forest conditions in Japan (Zhao et al 2013) and far East Russia suggest that F. mandshurica has lower susceptibility to shoot infection by H. fraxineus than F. excelsior, although lesions may develop after direct stem inoculation [on F. mandshurica var. japonica (Gross and Holdenrieder 2015)].…”

“…Based on observations from Estonian parks, F. nigra seems to be highly susceptible to shoot infection, while F. americana and F. pennsylvanica are more tolerant (Drenkhan and Hanso 2010). Inoculation studies have further shown that F. pennsylvanica develops minor lesions after stem inoculation with H. fraxineus (Gross and Sieber 2016;Kowalski et al 2015).…”

Fraxinus sogdiana, a Central Asian ash species, is susceptible to Hymenoscyphus fraxineus

“…51, 2015, No. 3: 150-152 145 725) from a symptomatic shoot as described by Drenkhan & Hanso (2010). DNA extraction from mycelia, ITS-PCR reactions and sequences were carried out as described by Drenkhan et al (2014b).…”