Articles by Dag Lindgren

Germination of Norway spruce (Picea abies (L.) H. Karst.) and Scots pine (Pinus sylvestris L.) pollen decreased during exposure to open air conditions. Usually more than half of the pollen remained germinative after a few days outdoors, but following more than four days outdoors the germination became very low. This study supports the opinion that pollen in the atmosphere remains viable long enough to allow for long-distance gene flow by pollen migration, as an important factor in genetic management of conifers and in evolution, maintaining diversity and potential for adaptation.

• Lindgren, E-mail: kl@mm.unknown
• Lindgren, E-mail: dl@mm.unknown

Four different methods of truncation selection were studied in a population consisting of a large number of unrelated full sib families of equal size: phenotype selection, family selection, within-family selection and combined index selection (optimal weighting of individual and family performance to get the best prediction of breeding value). Methods were developed for calculating diversity (”relative effective family number”) for the different selection methods. Numerical calculations were made for genetic gain and diversity. Model assumptions are additive gene control and normal distribution. Phenotypic was good at high heritabilities and between family at low heritabilities. Loss of diversity was strongly dependent on selection method and selection strength. Compared at the same diversity, genetic gain was lower for combined index compared to phenotypic. There is a need for methods combining the goals gain and diversity.

The PDF includes an abstract in Finnish.

• Wei, E-mail: rw@mm.unknown
• Lindgren, E-mail: dl@mm.unknown

• Andersson, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden E-mail: erik.andersson@genfys.slu.se
• Spanos, N.AG.RE.F.-Forest Research Institute, 57006 Vassilika, Thessaloniki, Greece E-mail: kas@nn.gr
• Mullin, Genesis Forest Science Canada Inc., C.P. 64 Succursale Haute-Ville, Québec, QC G1R 4M8 Canada E-mail: tjm@nn.ca
• Lindgren, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83, Umeå, Sweden E-mail: dl@nn.se