Pollen contamination is a severe problem in production breeding programs since it reduces the expected gain. In an attempt to solve this problem Skogforsk created an isolation experiment in the advanced Scots pine (Pinus sylvestris) seed orchard Västerhus in Västerbotten, Sweden. This experiment involves covering blocks of trees with a tent during the pollination period so that they only can mate with each other inside. To evaluate the effects of this tent treatment one tree from inside a tent with supplementary mass pollination (SMP) and one tree from the open control were chosen for this study. 48 seeds from each tree were sampled and genotypes at 9 microsatellite (SSR) loci. The likelihood and exclusion methods for paternity assignment were used to establish the fathers to these seeds. The results showed 0% contamination inside the tent and 4-8% outside in the control. The number of fathers contributed to the fertilization of the 48 seeds was 9 inside and 15 outside. The selfing rate was unexpectedly high, 10% inside the tent and 19% outside. The mating system inside the tent need to be further evaluated to fully understand what other effect the treatment has on the future progeny.

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree. The results show a big difference in pollen contamination between the two trees. The tree inside the tent showed a contamination rate of 0% and the tree from the open pollination had a contamination rate of 20,5%. No difference was found in the numbers of different fathers although the selfing rate of 4,26% was higher in the tent than the selfing rate of 2,56% observed in the open pollination environment. These results match the results of other studies done on the same orchard pretty well and therefore tent isolation with a supplementary pollination can be a good way to reduce unwanted pollen contamination.

In this study, pollen contamination (measured by the number of seeds pollinated by pollen not belonging to any of the clones on the seed orchard) is compared between open pollination and isolated pollination environments in a Scots pine (Pinus sylvestris) seed orchard called Västerhus, located outside Önsköldsvik. In this seed orchard a tent experiment is taking place. Skogforsk has built six large tents covering 12-14 trees with each tent. Fertilization patterns were compared between one tree in a tent with a supplementation of pollen from five clones not represented in the tent and another tree of the same clone subject to open pollination outside the tents. By using DNA markers the paternity was determined for 48 seeds from each tree. The results show a big difference in pollen contamination between the two trees. The tree inside the tent showed a contamination rate of 0% and the tree from the open pollination had a contamination rate of 20,5%. No difference was found in the numbers of different fathers although the selfing rate of 4,26% was higher in the tent than the selfing rate of 2,56% observed in the open pollination environment. These results match the results of other studies done on the same orchard pretty well and therefore tent isolation with a supplementary pollination can be a good way to reduce unwanted pollen contamination.