FSP 2004/05 Annual Technical Report Evaluating the Protocol for Quantifying Pollen Contamination on the Genetic Worth of Conifer Seed Orchards. Project Y051110 Joe Webber and Michael Stoehr Introduction Since all conifers are wind pollinated, orchards located within the natural range of the species are susceptible to non-orchard sources of pollen (contamination). Contaminate pollen is considered to have a negative effect on both the orchard’s estimated genetic worth of the improved trait (for example growth) and the adaptive potential of seed orchard progeny. To register seed for use on crown land, orchard managers must calculate the weighted gamete contribution (both male and female) for each seedlot (Woods et al. 1996, Stoehr et al. 2004, Woods 2004). Where contamination levels are high (>50%), a substantial reductions in the orchard’s genetic worth would occur. For example, a seedlot rated at a genetic worth of 20% and exposed to 50% contamination would lose 5% of the seedlot’s GW contributed by the pollen resulting in a net reduction of the seedlot’s GW to 15%. Since a seedlot’s GW is now incorporated in timber supply analyses, even a 5% loss in growth potential would also equate to a 5% loss in wood volume or more if the planting stock is also poorly adapted. Our current protocol for assessing the contribution of pollen contamination uses pollen monitoring technique. Both the period of pollen shed and the density of pollen clouds for both orchard and non-orchard sources are measured. Depending on the orchard site, the genetic worth of a specific orchard parent is reduced by the proportion of total contaminate pollen to orchard pollen. The species selected for this study is coastal Douglas-fir since most of the orchards are located on eastern Vancouver Island and one in Sechelt. The assumption made with the current protocol for estimating the gamete contribution of contaminate pollen is that contaminate pollen is related to its calculated proportion in the orchard pollen cloud as measured by pollen monitoring technique. Until recently, we had no better way to assess pollen contamination. Now paternity analyses, using molecular technique has been successfully developed for seed orchard applications. While it is possible to identify both orchard and non-orchard sources of pollen parents using DNA fingerprinting, it is unlikely we will adopt this new technique for routine gamete contribution. It will, however, allow us to assess the accuracy of our current pollen monitoring technique. The objective of this first year project was to measure the extent and magnitude of Douglas-fir pollen contamination in two contrasting orchard sites on Vancouver Island