Hopp til hovedinnholdet

Publikasjoner

NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.

2023

Til dokument

Sammendrag

Ophiostomatales (Ascomycota) contains many species, most of which are associated with bark beetles. Some members of this order are plant or animal pathogens, while others colonize soil, different plant tissues, or even carpophores of some Basidiomycota. However, little is known about soil-inhabiting Ophiostomatales fungi. A survey of these fungi associated with soil under beech, oak, pine, and spruce stands in Poland yielded 623 isolates, representing 10 species: Heinzbutinia grandicarpa, Leptographium procerum, L. radiaticola, Ophiostoma piliferum, O. quercus, Sporothrix brunneoviolacea, S. dentifunda, S. eucastaneae, and two newly described taxa, namely Sporothrix roztoczensis sp. nov. and S. silvicola sp. nov. In addition, isolates collected from fallen shoots of Pinus sylvestris that were pruned by Tomicus sp. are described as Sporothrix tumida sp. nov. The new taxa were morphologically characterized and phylogenetically analyzed based on multi-loci sequence data (ITS, β-tubulin, calmodulin, and translation elongation factor 1-α genes). The Ophiostomatales species were especially abundant in soil under pine and oak stands. Leptographium procerum, S. silvicola, and S. roztoczensis were the most frequently isolated species from soil under pine stands, while S. brunneoviolacea was the most abundant in soil under oak stands. The results highlight that forest soil in Poland has a wide diversity of Ophiostomatales taxa, but further studies are required to uncover the molecular diversity and phylogenetic relationships of these fungi, as well as their roles in soil fungal communities.

Til dokument

Sammendrag

This study aimed to determine the differences and drivers of oomycete diversity and community composition in alder- and birch-dominated park and natural forest soils of the Fennoscandian and Baltic countries of Estonia, Finland, Lithuania, Norway, and Sweden. For this, we sequenced libraries of PCR products generated from the DNA of 111 soil samples collected across a climate gradient using oomycete-specific primers on a PacBio high-throughput sequencing platform. We found that oomycete communities are most affected by temperature seasonality, annual mean temperature, and mean temperature of the warmest quarter. Differences in composition were partly explained by the higher diversity of Saprolegniales in Sweden and Norway, as both total oomycete and Saprolegniales richness decreased significantly at higher longitudes, potentially indicating the preference of this group of oomycetes for a more temperate maritime climate. None of the evaluated climatic variables significantly affected the richness of Pythiales or Peronosporales. Interestingly, the relative abundance and richness of Pythiales was higher at urban sites compared to forest sites, whereas the opposite was true for Saprolegniales. Additionally, this is the first report of Phytophthora gallica and P. plurivora in Estonia. Our results indicate that the composition of oomycetes in soils is strongly influenced by climatic factors, and, therefore, changes in climate conditions associated with global warming may have the potential to significantly alter the distribution range of these microbes, which comprise many important pathogens of plants.

Til dokument

Sammendrag

The efficacy of currently available fungicides against apple scab, caused by the fungal pathogen Venturia inaequalis, was investigated in relation to when growers spray (ahead, during, or after rain) and how the spray reaches the target. The adaxial surface of individual leaves of potted trees were sprayed and then inoculated with ascospores of V. inaequalis, to establish dose-response curves for each fungicide. Discriminatory doses providing 50 and 90% symptom inhibition (EC50 and EC90, respectively) in sprays mimicking applications ahead of rain were used for experiments imitating alternative spray timings. Sprays were either applied during the spore germination phase or early or late after infection onset (either 336 or 672 degree-hours after inoculation, respectively), corresponding to grower spray schedules. Experiments were also carried out with sprays applied on the abaxial leaf surface to investigate fungicide efficacy through the leaf lamina. For all fungicides, the best efficacy was observed when sprays were applied during germination, followed by applications ahead of inoculation. Some products maintained equal or better efficacy at early infection, while efficacy in late infection dropped for all products, clearly indicating that this spray timing should be avoided. Some products with postinfection efficacy also showed translaminar efficacy. The close relationship found between EC50 of the active ingredients on potted trees and the label rate could help improve spraying decisions and reduce costs.