Development of EST-PCR markers and monitoring their intrapopulational genetic variation in Picea abies (L.) Karst.

Abstract 

Fifteen cDNA sequences are reported for the European coniferous forest tree species Norway spruce [Picea abies (L.) Karst.], including the results of similarity searches in public electronic databases. The sequences were subsequently employed for the design of specific primer pairs and PCR-based amplification of genomic fragments. For seven primer pairs, polymorphic EST-PCR markers were identified among 18 trees. Their mode of inheritance was verified by analysing single-tree offspring and studying segregation among haploid endosperms in comparison to diploid tissue. Codominant inheritance was indicated for six markers, while one marker was apparently dominant. Variation of the six codominant EST markers was tested by genotyping 110 randomly selected trees in a Bavarian Norway spruce population. For comparison, the same trees were genotyped at 18 enzyme coding gene loci. There were 3.33 alleles per locus for EST markers and 3.00 for isoenzyme gene markers. In general, a trend to more even frequency distributions and larger intrapopulational variation, including observed heterozygosities, was indicated more for EST markers than for isoenzyme gene markers. The benefits of these newly developed EST-PCR markers are outlined with respect to population genetics and ecological genetics.