The association of the genes HvNAM1 and HvNAM2 with grain protein content in Nordic barley

Sammanfattning: In barley, the GPC (Grain Protein Content) has proved to be of great importance for both feed, food and beer production. When it comes to feed and food, a high GPC is desirable since it indicates good nutritional values, while in beer production a low and stable GPC is needed to avoid beer chill haze. In previous studies a decrease in the GPC has been seen in different accessions of barley developed at different time periods during the last 100 years. The gene family HvNAM, including the genes HvNAM1 and HvNAM2, has in previous studies been shown to be important for the remobilization of nutrients towards the grains during the senescence and thus also for the GPC. In this study, 40 Nordic accessions from different improvement groups from the end of the 19th century until today have been analyzed for polymorphism in those genes. Statistical analyses has been conducted to investigate if there are any associations between the polymorph nucleotide positions and the nutritional values of grain protein, iron and zinc contents. However, no such associations were found. Instead some correlations could be seen between the nutrient content and thousand grain weight, a relative measurement of the grain size. In conclusion, since no polymorphisms were found to be associated to the nutritional value there might instead be a correlation between the gene expression and the nutritional value. Future work should thus focus on the gene expression of HvNAM1 and HvNAM2 in Nordic accessions of barley.