Hopp til hovedinnholdet

Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2011

To document

Abstract

In Norway spruce, the temperature during zygotic embryogenesis appears to adjust an adaptive epigenetic memory in the progeny that may regulate bud phenology and cold acclimation. Conditions colder than normal advance the timing whilst temperatures above normal delay the onset of these processes and altered performance is long lasting in progeny with identical genetic background. As a step toward unraveling the molecular mechanism behind an epigenetic memory, transcriptional analysis was performed on seedlings from seeds of six full-sib families produced at different embryogenesis temperature?cold (CE) vs warm (WE) under long and short day conditions. We prepared two suppressive subtractedcDNAlibraries, forward and reverse, representing genes predominantly expressed in plants from seeds obtained after CE and WE embryogenesis following short day treatment (inducing bud set). Sequencing and annotation revealed considerable differences in the transcriptome of WE versus CE originated plants. By using qRT-PCR we studied the expression patterns of 32 selected candidate genes chosen from subtractive cDNA libraries analysis and nine siRNA pathways genes by a direct candidate approach. Eight genes, two transposons related genes, three with no match to Databases sequences and three genes from siRNA pathways (PaDCL1 and 2, PaSGS3) showed differential expression in progeny from CE andWEcorrelated with the family phenotypic differences. These findingsmaycontribute to our understanding of the epigenetic mechanisms underlying adaptive changes acquired during embryogenesis.

To document

Abstract

Grouse and vole numbers may peak after peaks in the seed crop of bilberry (Vaccinium myrtillus) because of reduced levels of feeding deterrents in bilberry plants. We predicted that grouse reproduction depends also on summer (June-September) temperatures in the 2 previous years, because bilberry plants will be less exhausted after a high seed crop in or after warm summers, and thus rebuild their chemical defence more quickly. After berry peak years, population indices of capercaillie (Tetrao urogallus) and bank vole (Myodes glareolus) in southern Norway were negatively related to summer temperatures in the previous year or previous 2 years. Willow grouse (Lagopus lagopus) chick production in five areas in Norway was negatively related to summer temperatures in the 2 previous years when controlling for vole density. A similar pattern was found for the bilberry-feeding moth (Eulithis populata), an important prey for grouse chicks. In eastern Norway, autumn densities of capercaillie and black grouse (Tetrao tetrix) were more likely to peak in vole peak years at high altitudes, where summer temperatures are low. We conclude that high summer temperatures may limit grouse reproduction through the effect on bilberry plants and that a warm climate thus adversely affects population levels of grouse.