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.
2009
Forfattere
Yibrah Beyene Trond Hofsvang Ferdu AzerefegneSammendrag
Fenologien og migrasjon hos den plantespisende marihønen Chnootriba similis ble undersøkt i Etiopia i årene 2003-2005 langs to elver og i byggåkre 2004-2005. Arten overlever i tørkeperioder langs elvene som voksne i diapause som avsluttes ca. midt i januar. De migrerer til åkre i mars - april. Opphøret av diapause og migrasjon påvirkes av nedbør. Det er to generasjoner i året. Voksne fra den andre generasjonen migrerer til elvene i september - oktober. Arten er først og fremst et skadedyr på unge planter.
Forfattere
Abdelhameed ElameenSammendrag
Abstract Germplasm characterization is an important component contributing to the effective management of plant genetic resources. The goal of this thesis was to study the genetic diversity of two models of vegetatively propagated plant species; roseroot (Rhodiola rosea L.) and sweet potato (Ipomoea batatas (L.) Lam), based on germplasm collections. Roseroot was recently collected from natural habitats and then vegetatively propagated at the germplasm centre while sweet potato already has a long tradition as a vegetatively propagated food species. I. Roseroot (Rhodiola rosea) Roseroot, R. rosea, also commonly known as golden root or arctic root, is a perennial herbaceous plant of the Crassulaceae family. R. rosea has its origin from the cold, humid regions of the northern hemisphere and grows mostly in the mountains near the snow border. R. rosea is widely distributed in Norway. As part of an effort to identify commercially valuable genotypes characterization of a germplasm collection from Norway was initiated. Amplified Fragment Length Polymorphism (AFLP) analysis was used to estimate genetic diversity within the Norwegian R. rosea germplasm collection. AFLP analysis of 97 R. rosea clones using five primer combinations gave a total of 109 polymorphic bands. A large molecular marker variation was found among roseroot clones in Norway with an average percentage of polymorphic bands (PPB) of 82.3%. Analysis of molecular variance (AMOVA) revealed a significantly greater variation within regions (92.03%) than among regions (7.97%) demonstrating that there was no close genetic similarity among clones originating from the same county. A low level of genetic differentiation (FST = 0.043) was observed, indicating a high level of gene flow, which had a strong influence on the genetic structure in Norway. Our results indicate high gene flow among R. rosea clones that might be a result of seed dispersal rather than cross-pollination. Ninety five clones of the Norwegian roseroot germplasm collection were analysed and quantified for their content of the bioactive compounds rosavin, salidroside, rosin, cinnamyl alcohol and tyrosol using High Performance Liquid Chromatography (HPLC) analysis. All bioactive compounds were detected in all clones but in highly variable quantities. The frequency distribution of the chemical content of each clone was not correlated with geographic region of origin or gender of the plant. Significant correlations between the content of these bioactive compounds were observed within individual roseroot clones. Low and nonsignificant correlations were found between AFLP markers used to study genetic diversity of the roseroot clones and their content of chemical compounds. The maximum content of rosavin, rosin and salidroside observed were substantially higher than previously reported for roseroot plants, and the roseroot clones characterized in this study might therefore be of high pharmacological value. The large quantitative and qualitative variation of the chemical compounds observed in this study and the large genetic diversity observed in this germplasm constitute a firm basis for improving traits such as chemical composition in a breeding program for roseroot. This is the first report that combines the analysis of genetic diversity with information of the chemical composition of roseroot. Further studies of the roseroot populations from Norway as well as from other countries should be performed throughout the following years to identify clones with optimal chemical compositions and to maintain high genetic diversity of this species. II. Sweet potato (Ipomoea batatas (L.) Lam) Sweet potato has its origin in South America and is the 7th most important crop in the world. A Tanzanian sweet potato germplasm collection was characterized using molecular markers and morphological traits. The AFLP method was used to study the genetic diversity and relationships of sweet potato accessions in the germplasm collection ..
Forfattere
Maria-Luz Herrero Brita ToppeSammendrag
Ramorum-greinvisning er en ny plantesykdom i Europa og Amerika forårsaket av pseudosoppen P. ramroum. Den ble oppdaget midt på 1990-tallet. Langs vestkysten av USA, fra California til Oregon, forårsaket den stor dødelighet i eikeskog og ble kjent som Sudden Oak Death (SOD).
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
Karl ThunesSammendrag
Det er ikke registrert sammendrag
Forfattere
Martha EbbesvikSammendrag
Planelggingsprogrammet er nyttig for å beregne dekningsbidrag ved dagens drift og hvis gården legges om til økologisk drift. Avlingsnivå kan beregnes ut dyretall, fôrlager, opptak på beite eller fra opplysninger fra enkelt skifter.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Anna-Karin Borg-Karlsson Anna-Karin Borg-Karlsson Jerry Cross Lene SigsgaardSammendrag
Introduction: The strawberry blossom weevil, Anthonomus rubi, is a major pest insect of cultivated strawberry in northern part of Europe. The weevils deposit eggs in the flower buds before it sever the buds from their stalks, leading to a direct loss of crop. The aim of this project is to develop an effective plant protection method without insecticides, to be used in both conventional and organic agriculture.Methods: Volatiles emitted by the strawberry plants were collected using SPME and identified by GC/MS. In field studies which took place in Norway, Denmark and UK funnel traps bated with different plant volatile compounds and the pheromone blend Grandlure were tested. The volatiles were tested separately and in mixtures. On the background of the results from the first two years optimisation of the mixture were carried out during the third year of field trails. This process included adding more test compounds and testing the most potent compound at different concentrations. In addition, modified traps were tested for improving insect catch rates. Results: The chemical analysis of the host volatiles identified several compounds present in different quantities. At some study sites traps baited with one of the identified plant compound and Grandlure showed significant increased attraction compared to traps bated with the single plant compound or only Grandelure. The results from the optimisation process showed different catch rates of weevils according to composition of the volatile mixture and the trap design.Conclusions: The result shows that there may be is a synergistic effect between one of the plant volatile compounds and the pheromone blend Grandlure when used as bait for trapping strawberry blossom weevils. However, this attraction can be reduced by adding more compounds. Hopefully, the result from this study will generate knowledge important for developing a new plant protection method for strawberry.
Forfattere
Geir Kjølberg Knudsen Marco TasinSammendrag
Abstract: Apple fruit moth Argyresthia conjugella (Zeller) (Lepidoptera: Argyresthiidae) is the most important insect pest in apples in Fennoscandia. Its principle host is the masting forest three rowan Sorbus aucuparia. Damage to apple occurs only in intermasting years when rowan produces low crop. A monitoring tool is needed to detect the timing of female migration to apple in order to precisely apply control measures. Volatile plant compounds may be used to trap migrating females searching for the alternative host during intermasting years. In this study we present data from field monitoring experiments. In 2007 we carried out a field test in apple with the aim to screen for behaviorally active compounds beside those already described by Bengtsson et al. (2006). In traps baited with three component blends we found four compounds that could be regarded as synergists. These compounds were in 2008 tested both in rowan and apple. We detected insects by both visual inspections and trapping in a rowan stand, whilst only traps baited with the candidate compounds could detect migrating insects in apple orchards. The number in apple however was low due to the fact that 2008 was a low-attack season and the majority of the moths remained in the rowan stands. Improvements of blend composition for field monitoring may be achieved by additional field tests in damage years in combination with ongoing wind tunnel studies.
Forfattere
Åsmund AsdalSammendrag
Det er ikke registrert sammendrag