Pollen contamination and mating system of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) clone banks used as an interim seed orchard near Nanaimo, B.C., were estimated. Pollen contamination (m) from surrounding clone banks and natural stands ranged from 0.44 to 0.89. Overall contamination over 2 years was estimated to be 0.65. Pollen contamination varied significantly over 2 pollination years. Multilocus outcrossing rates (t) of four clone banks over 2 years ranged from 0.51 to 1.09, with an unweighted mean outcrossing estimate of 0.72. Outcrossing varied significantly among clone banks and pollination years. An excess of homozygotes suggests that these seed may be inbred. Although pollen contamination and inbreeding may be a problem in these clone banks, the seed may still be useful operationally.

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