Skip to main content
SLU publication database (SLUpub)
Research article - Peer-reviewed, 2021

Halophytophthora fluviatilis Pathogenicity and Distribution along a Mediterranean-Subalpine Gradient

Caballol, Maria; Straus, Dora; Macia, Hector; Ramis, Xavier; Redondo, Miguel A.; Oliva, Jonas


Halophytophthora species have been traditionally regarded as brackish water oomycetes; however, recent reports in inland freshwater call for a better understanding of their ecology and possible pathogenicity. We studied the distribution of Halophytophthora fluviatilis in 117 forest streams by metabarcoding river filtrates taken in spring and autumn and by direct isolation from floating leaves. Pathogenicity on six Fagaceae species and Alnus glutinosa was assessed by stem inoculations. The distribution of H. fluviatilis was correlated with high mean annual temperatures (>93.5% of reports in Ta > 12.2 degrees C) and low precipitation records. H. fluviatilis was therefore widely distributed in forest streams in a warm-dry climate, but it was mostly absent in subalpine streams. H. fluviatilis was primarily detected in autumn with few findings in spring (28.4% vs. 2.7% of streams). H. fluviatilis was able to cause small lesions on some tree species such as Quercus pubescens, Q. suber and A. glutinosa. Our findings suggest that H. fluviatilis may be adapted to warm and dry conditions, and that it does not pose a significant threat to the most common Mediterranean broadleaved trees.


oomycetes; Quercus suber; Alnus glutinosa; climate change

Published in

Journal of Fungi
2021, Volume: 7, number: 2, article number: 112
Publisher: MDPI

    UKÄ Subject classification


    Publication identifier


    Permanent link to this page (URI)