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.
2017
Sammendrag
Nighttime ultraviolet (UV) radiation, if applied properly, has a significant potential for management of powdery mildews in many crop species. In this study, the role of growth light duration, irradiance, a combination of both (daily light integral) and light spectral quality (blue or red) on the efficacy of UV treatments against powdery mildew caused by Podosphaera xanthii and the growth performance of cucumber plants was studied in growth chambers. Increasing daily light integral provided by high-pressure sodium lamps (HPS) decreased efficacy of nighttime UV treatments against P. xanthii, but it increased plant growth. Furthermore, the efficacy of nighttime UV decreased when day length was increased from 16 to 20 h at a constant daily light integral. The efficacy of nighttime UV increased if red light was applied after UV treatment, showing the possibility of day length extension without reducing the effect of UV. Increasing the dose of blue light during daytime reduced the efficacy of nighttime UV in controlling the disease, whereas blue deficient growth light (< 6% of blue) caused UV mediated curling of young leaves. Furthermore, application of blue light after nighttime UV reduced its disease control efficacy. This showed the importance of maintaining a minimum of blue light in the growth light before nighttime UV treatment. Findings from this study showed that optimization of nighttime UV for management of powdery mildew is dependent on the spectral composition of the photosynthetically active radiation.
Sammendrag
Fire blight, caused by Erwinia amylovora, was detected for the first time in Norway in 1986. It was a limited outbreak on the south-western coast, only on ornamentals, and particularly on Cotoneaster spp. An action group handling the eradication and containment of the disease was quickly established. Comprehensive statutory powers and resources were given by the government to do surveys and eradicate diseased or symptomless but highly susceptible plant species from contaminated areas. These activities have likely restricted fire blight to the western and southern coastal areas. Eastern and northern parts of Norway are considered free from fire blight. The disease has not been observed in important fruit-growing areas. Uncontrolled movement of beehives from areas with fire blight to areas free from the disease has contributed to its introduction to new areas. From 1969 to 2016 import of most host plants of E. amylovora from countries with fire blight was prohibited. A yearly program for annual surveys in parts of the country with commercial fruit-growing and nurseries, using digital maps on internet connected tablets with GPS and software for in situ registrations, proved to be an efficient method for discovering new outbreaks at an early stage, and to start eradication and thus limit further spread.
Sammendrag
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Sammendrag
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Sammendrag
The aim of this study was to evaluate the natural occurrence of Beauveria spp. in soil, from infections in the stink bug Piezodorus guildinii, an important pest of common bean (Phaseolus vulgaris) and as endophytes in bean plant tissue. Twelve conventional and 12 organic common bean fields in the Villa Clara province, Cuba were sampled from September 2014 to April 2015. One hundred and fifty Beauveria isolates were obtained from soil samples, bean plant parts and stink bugs. The overall frequency of occurrence of Beauveria isolates in conventional fields (8.4%) was significantly lower than that in organic fields (23.6%). Beauveria were also obtained significantly more frequently from bean roots in organic fields (15.0%) compared to bean roots in conventional fields (3.3%). DNA sequencing of the intergenic Bloc region was performed for Beauveria species identification. All isolates where characterized as Beauveria bassiana (Balsamo-Crivelli) Vuillemin, and clustered with isolates of neotropical origin previously described as AFNEO_1. The Cuban B. bassiana isolates formed five clusters in the phylogeny. Isolates of two clusters originated from all four locations, organic and conventional fields, as well as soil, plants and stink bugs. Organic fields contained isolates of all five clusters while conventional fields only harbored isolates of the two most frequent ones. Mating type PCR assays revealed that mating type distribution was skewed, with MAT1/MAT2 proportion of 146/4, indicating limited potential for recombination. The present study is the first to report of B. bassiana as a naturally occurring endophyte in common bean. Further, it shows that B. bassiana occurs naturally in diverse environments of common bean fields, and constitutes a potential reservoir of natural enemies against pest insects particularly in organic fields.
Sammendrag
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Forfattere
Mihaela-Olivia Dobrica Catalin Lazar Lisa Paruch Hanne Skomedal Hege Særvold Steen Sissel Haugslien Catalin Tucureanu Iuliana Caras Adrian Onu Sonya Ciulean Alexandru Branzan Jihong Liu Clarke Crina Stavaru Norica Branza-NichitaSammendrag
Chronic Hepatitis B Virus (HBV) infection leads to severe liver pathogenesis associated with significant morbidity and mortality. As no curable medication is yet available, vaccination remains the most costeffective approach to limit HBV spreading and control the infection. Although safe and efficient, the standard vaccine based on production of the small (S) envelope protein in yeast fails to elicit an effective immune response in about 10% of vaccinated individuals, which are at risk of infection. One strategy to address this issue is the development of more immunogenic antigens. Here we describe a novel HBV antigen obtained by combining relevant immunogenic determinants of S and large (L) envelope proteins. Our approach was based on the insertion of residues 21-47 of the preS1 domain of the L protein (nomenclature according to genotype D), involved in virus attachment to hepatocytes, within the external antigenic loop of S. The resulting S/preS121-47 chimera was successfully produced in HEK293T and Nicotiana benthamiana plants, as a more economical recombinant protein production platform. Comparative biochemical, functional and electron microscopy analysis indicated assembly of the novel antigen into subviral particles in mammalian and plant cells. Importantly, these particles preserve both S- and preS1-specific epitopes and elicit significantly stronger humoral and cellular immune responses than the S protein, in both expression systems used. Our data promote this antigen as a promising vaccine candidate to overcome poor responsiveness to the conventional, S protein-based, HBV vaccine.
Forfattere
Stig A. BorgvangSammendrag
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Forfattere
Tage ThorstensenSammendrag
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Forfattere
Paal KrokeneSammendrag
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