Correction added after online publication 24 December 2008: eqn 2 was changed from to .
Extensive pollen flow in two ecologically contrasting populations of Populus trichocarpa
Article first published online: 8 DEC 2008
© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd
Volume 18, Issue 2, pages 357–373, January 2009
How to Cite
SLAVOV, G. T., LEONARDI, S., BURCZYK, J., ADAMS, W. T., STRAUSS, S. H. and DIFAZIO, S. P. (2009), Extensive pollen flow in two ecologically contrasting populations of Populus trichocarpa. Molecular Ecology, 18: 357–373. doi: 10.1111/j.1365-294X.2008.04016.x
S. H. Strauss and S. P. Difazio contributed equally to this work.
Correction added after online publication 24 December 2008: Vinson (small scale) was moved to the third row in Table 3.
Correction added after online publication 24 December 2008: the y axis label ‘Frequency of pollinations’ in Fig 4 was corrected to ‘Frequency of pollination’.
- Issue published online: 14 JAN 2009
- Article first published online: 8 DEC 2008
- Received 18 August 2008; revision received 8 October 2008; accepted 17 October 2008
- black cottonwood;
- correlated paternity;
- gene flow;
- parentage analysis;
Pollen-mediated gene flow was measured in two populations of black cottonwood using direct (paternity analysis) and indirect (correlated paternity) methods. The Marchel site was an area with an approximate radius of 250 m in a large continuous stand growing in a mesic habitat in western Oregon. In contrast, the Vinson site was an area with a radius of approximately 10 km and consisted of small, disjunct and isolated stands in the high desert of eastern Oregon. Pollen immigration was extensive in both populations, and was higher in the Marchel site (0.54 ± 0.02) than in the substantially larger and more isolated Vinson site (0.32 ± 0.02). Pollen pool differentiation among mothers was approximately five times stronger in the Vinson population (ΦFT = 0.253, N = 27 mothers) than in the Marchel population (ΦFT = 0.052, N = 5 mothers). Pollen dispersal was modelled using a mixed dispersal curve that incorporated pollen immigration. Predicted pollination frequencies generated based on this curve were substantially more accurate than those based on the widely used exponential power dispersal curve. Male neighbourhood sizes (sensu Wright 1946) estimated using paternity analysis and pollen pool differentiation were remarkably similar. They were three to five times smaller in the Vinson population, which reflected the substantial ecological and demographic differences between the two populations. When the same mathematical function was used, applying direct and indirect methods resulted in similar pollen dispersal curves, thus confirming the value of indirect methods as a viable lower-cost alternative to paternity analysis.