Venche Talgø
Research Scientist
Abstract
Authors: Franić, I, S Prospero, KA, EA, FA, MAA-R, SA, DA, WB, MB, KB, AB, PB, HB, TB, MB Brurberg, TB, DB, MC, JC, DC, GC, K, KD, MdeG, JD, HTDL, RD, JE, ME, CBE, RF, JF, NF, ÁF-M, MG, BG, MH, LH, MKH, MH, MJJ, MK, MK, NK, MK, VK, NL, MVL, JL, ML, HL, CLM, CM, DM, IM, TM, JM, DM, CN, RO'H, FO, TP, TP, BP, HR, JR, AR, AR, BR, KS, CS, V Talgø, МТ, AU, MU, AMV, CV, YW, JW, MZ, R Eschen. Abstract: Non-native pests, climate change, and their interactions are expected to disrupt the relationships between trees and the organisms associated with them, thereby impacting forest health. In order to comprehend and anticipate these changes, it is crucial to identify the factors that shape tree-associated communities. We collected and analysed insects and fungi obtained from dormant twigs of 155 tree species across 51 botanical gardens or arboreta in 32 countries on six continents. Fungi were characterized by high-throughput sequencing. Insects were first reared and then sorted into taxonomic orders and feeding guilds. Herbivorous insects were then grouped into morphospecies and were identified using molecular and morphological approaches. By employing generalized dissimilarity models, we assessed the relative significance of various climatic, host-related, and geographic factors in driving dissimilarities among tree-associated communities. This dataset reveals the diversity of tree- associated taxa, as it contains 12,721 amplicon sequence variants and 208 herbivorous insect morphospecies, sampled across broad geographic and climatic gradients and for many tree species. Mean annual temperature, the phylogenetic distance between hosts, and the geographic distance between locations were the primary determinants of dissimilarities. The increasing influence of high temperatures on community differences suggests that climate change could directly and indirectly impact tree-associated organisms through shifts in host ranges. Furthermore, insect and fungal communities exhibited greater similarity among closely related hosts compared to distantly related hosts, implying that expansion of host ranges could facilitate the emergence of new pests. Additionally, dissimilarities among tree-associated communities increased with geographic distance, suggesting that human-mediated transportation could lead to the introduction of new pests. These study results underscore the importance of limiting the introduction and establishment of tree pests and enhancing the resilience of forest ecosystems in response to climate change.
Authors
Katherine Ann Gredvig Nielsen Magne Nordang Skårn Venche Talgø Martin Pettersson Inger Sundheim Fløistad Gunn Strømeng May Bente Brurberg Arne StensvandAbstract
Gray mold, caused by Botrytis spp., is a serious problem in Norway spruce seedling production in forest nurseries. From 2013 to 2019, 125 isolates of Botrytis were obtained from eight forest nurseries in Norway: 53 from Norway spruce seedlings, 16 from indoor air, 52 from indoor surfaces, and four from weeds growing close to seedlings. The majority of isolates were identified as B. cinerea, and over 60% of these were characterized as Botrytis group S. B. pseudocinerea isolates were obtained along with isolates with DNA sequence similarities to B. prunorum. Fungicide resistance was assessed with a mycelial growth assay, and resistance was found for the following: boscalid (8.8%), fenhexamid (33.6%), fludioxonil (17.6%), pyraclostrobin (36.0%), pyrimethanil (13.6%), and thiophanate-methyl (50.4%). Many isolates (38.4%) were resistant to two to six different fungicides. A selection of isolates was analyzed for the presence of known resistance-conferring mutations in the cytb, erg27, mrr1, sdhB, and tubA genes, and mutations leading to G143A, F412S, ΔL497, H272R, and E198A/F200Y were detected, respectively. Detection of fungicide resistance in Botrytis from Norway spruce and forest nursery facilities reinforces the necessity of employing resistance management strategies to improve control and delay development of fungicide resistance in the gray mold pathogens.
Authors
Martin S. Mullett Anna R. Harris Bruno Scanu Kris Van Poucke Jared LeBoldus Elizabeth Stamm Tyler B. Bourret Petya K. Christova Jonás Oliva Miguel A. Redondo Venche Talgø Tamara Corcobado Ivan Milenković Marília Horta Jung Joan Webber Kurt Heungens Thomas JungAbstract
Phytophthora pseudosyringae is a self-fertile pathogen of woody plants, particularly associated with tree species from the genera Fagus, Notholithocarpus, Nothofagus and Quercus, which is found across Europe and in parts of North America and Chile. It can behave as a soil pathogen infecting roots and the stem collar region, as well as an aerial pathogen infecting leaves, twigs and stem barks, causing particular damage in the United Kingdom and western North America. The population structure, migration and potential outcrossing of a worldwide collection of isolates were investigated using genotyping-by-sequencing. Coalescent-based migration analysis revealed that the North American population originated from Europe. Historical gene flow has occurred between the continents in both directions to some extent, yet contemporary migration is overwhelmingly from Europe to North America. Two broad population clusters dominate the global population of the pathogen, with a subgroup derived from one of the main clusters found only in western North America. Index of association and network analyses indicate an influential level of outcrossing has occurred in this preferentially inbreeding, homothallic oomycete. Outcrossing between the two main population clusters has created distinct subgroups of admixed individuals that are, however, less common than the main population clusters. Differences in life history traits between the two main population clusters should be further investigated together with virulence and host range tests to evaluate the risk each population poses to natural environments worldwide.
Division of Biotechnology and Plant Health
Plant Pest Prevention through technology-guided monitoring and site-specific control (PurPest)
The main objective of PurPest is to control serious plant pests during import and to manage them in the field by developing a unique concept enabling pest detection in a timely and non-invasive manner.
Division of Food Production and Society
Risk management of imported plants and seeds: possibilities for improved pest detection to prevent the introduction and spread of new pests
Plant pathogens and invertebrates harmful to plants continue to threatenfood security and natural habitats. In Norway, the responsibility of performingplant health inspections on imported plants has gradually shifted to importersof plants who are currently responsible for internal pest control and mustbe registered with the Norwegian Food Safety Authority.