Biography

My focus is on plant diseases caused by plant viruses, viroids and phytoplasma:
  • Diagnosis
  • Epidemilogy
  • Control

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Abstract

I Jordbruksoppgjøret 2025 (Prp. 149 S (2024 – 2025)) ble det enighet om at kunnskapsstatus og -behov innen plantehelseområdet fra 2019 måtte oppdateres. Det er gjort i form av denne rapporten. Den bestilte utredningen er avgrenset til skadegjørere og planteverntiltak som er relevante for jord- og hagebruk. Utredingen tar for seg kunnskap, prosjekter og kunnskapshull siden 2019 og fram til i dag (2026). Kapittel 1 omtaler metodebruk og plantevern i et beredskapsperspektiv. Kapittel 2.1-2.8 omhandler status for utfordringer med skadegjørere og tilgang til planteverntiltak for alle aktuelle plantekulturer for ugras, skadedyr og sopp. Kapittel 2.9 gir en oversikt over godkjente og utgåtte plantevernmidler siden 2019. Kapittel 2.10 omhandler skadegjørere hvor kjemiske plantevernmidler er i begrenset bruk. Det vil si virus, bakterier og nematoder. Kapittel 3 tar for seg ny teknologi og innovative metoder for integrert plantevern og faktorer som påvirker bruken av disse. Kapittel 4 omhandler miljø- og helseeffekter knyttet til bruk av kjemiske plantevernmidler, hvilke plantekulturer som utgjør størst risiko for negative miljøeffekter og faktorer som reduserer helserisikoen. Kapittel 5 tar for seg næringens behov og utviklingstrekk knyttet til kunnskap, rådgivning og tiltak. Dette kapittelet ser også på årsaker til eventuelle endringer i bruk av og behov for plantevernmidler som følge av for eksempel miljøkrav.

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Abstract

We report the successful cryopreservation of three economically important Rubus viruses: raspberry bushy dwarf virus (RBDV), black raspberry necrosis virus (BRNV), and Rubus yellow net virus (RYNV), using shoot tip cryopreservation in four raspberry cultivars. Virus-infected shoot tips (approximately 1.0 mm in length) containing 3–4 leaf primordia (LPs) were cryopreserved using the droplet-vitrification technique. In the cultivars ‘Zlatá Královna (ZK)’ and ‘Tulameen (TUM)’, over 90% of shoot tips survived, and more than 90% regenerated into whole shoots. All three viruses were successfully preserved in the cryopreserved tissues, with recovery rates varying depending on virus type and cultivar: RBDV was recovered at rates of 86% in ‘ZK’ and 87% in ‘TUM’; BRNV at 66% in ‘ZK’ and 45% in ‘TUM’; and RYNV at 96%, 94%, and 86% in ‘Fairview’, ‘Stiora’, and ‘ZK’, respectively. To investigate viral localization in shoot tips, in situ hybridization was used. RBDV and RYNV infected a broad range of meristematic tissues, including the apical dome and LPs, whereas BRNV showed a more limited distribution. Virus distribution varied not only among virus species but also across raspberry cultivars, suggesting genotype-specific patterns of virus localization. Post-cryopreservation viral activity was verified using micrografting and aphid transmission assays. RBDV, BRNV, and RYNV were all successfully transmitted to healthy plants via micrografting, indicating the preservation of viral infectivity. Furthermore, BRNV was effectively transmitted by large raspberry aphids from cryopreserved materials, confirming vector-mediated transmission capacity post-thaw. Overall, this study demonstrates that shoot tip cryopreservation via droplet-vitrification is a reliable and effective strategy for preservation of biologically active Rubus viruses. This approach offers a valuable biotechnological tool for virus maintenance in support of diagnostic, breeding, and virology research.

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Abstract

Rapid population growth poses a major challenge to global food security. Promoting sustainable agricultural production is necessary to ensure the global food security. Horticultural plants are a high-valued part in agricultural production. Virus and viroid diseases have long been a key factor limiting the horticultural production. Cultivation and distribution of pathogen-free plants is currently the most efficient practice for managing virus and viroid diseases, and their spread in the landscape. Cryotherapy-based methods are recently developed novel biotechnologies for the efficient production of pathogen-free plants. This review outlines updated information on the development and advances in cryotherapy-based methods for efficiently eradicating viruses and viroids in horticultural plants. Mechanisms underlining cryotherapy-based methods for improved pathogen eradication are discussed, and suggestions for further studies are proposed.