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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.

2015

Sammendrag

Leaf blotch diseases in wheat can cause yield losses above 30 %. The necrotrophic fungus Parastagonospora nodorum is the dominating leaf blotch pathogen in Norwegian spring wheat. It has been well documented at the seedling stage that the pathogen produces necrotrophic effectors (NEs) which induces cell death in plants carrying susceptibility genes (Snn), allowing the necrotroph to enter. However, the role of these interactions under field conditions is less researched. In this study, we conducted field experiments with bi-parental and association mapping populations of spring wheat, to investigate the role of NE/Snn in adult plant resistance. The populations have been genotyped with the Illumina 90 K SNP chip, P. nodorum has high genetic diversity and both sexual and asexual reproduction, but the actual adaptation of the pathogen population to cultivars with different levels of resistance is not well studied. We are screening a collection of Norwegian isolates from known host sources to look for differences in NE-frequencies and haplotype distribution. The mapping populations are also inoculated and infiltrated with culture filtrates from single isolates on the seedling stage. Isolates involved in novel interactions will be deepsequenced in order to look for candidate effector genes. Potential effector proteins will be purified by LPC and HPLC to confirm their role in disease development.

Til dokument

Sammendrag

Methods for control of couch grass (Elymus repens L.) with reduced tillage and cover crops to achieve low risk of nitrogen (N) and phosphorus (P) leaching were investigated. Treatments with reduced post-harvest tillage (one or two passes with duckfoot cultivator), hoeing between rows in combination with a cover crop, and a cover crop mown twice during autumn were compared with treatments with conventional disc cultivation and the control without tillage or cover crop. The study was conducted on a sandy soil in Sweden with measurements of N and P leaching. A 2-year experimental protocol was used, repeated twice. Treatments were implemented in the first year, and effects on couch grass (shoot density, shoot and rhizome biomass) were measured during autumn and in the second year. Significant effects of a single duckfoot cultivation and cover crop strategies were observed on couch grass shoot density in autumn but persistent effects were not verified. In conclusion, a single cultivation after harvest instead of repeated reduced the risk of N leaching and a cover crop in combination with hoeing or mowing effectively reduced it. Repeated cultivations resulted in mean annual N leaching of 26 kg N ha−1 compared with 20 kg in the treatment with one cultivation, 17 kg in the control, 16 and 12 kg in cover crop treatments with mowing and hoeing, respectively. The P leaching was small (0.04–0.09 P ha−1 year−1), but there were indications of increased P drainage water concentrations in the treatment with a cover crop which was mown.