Estimating the Parameters of Pollen Flow and Mating System in Pinus densiflora Population in Buan, South Korea, Using Microsatellite Markers

Abstract

-Parameters of mating system and pollen flow of a Pinus densiflora population in Buan, South Korea, were estimated using seven nuclear microsatellite markers. The expected heterozygosity (He) was 0.614 in mother trees and 0.624 in seeds. Fixation index (F) was 0.018 and 0.087 in each generation. There was no significant genetic difference between the generations (P > 0.05). From MLTR, the outcrossing rate (tm), the biparental inbreeding (tm-ts), and the correlation of paternity (rp) were 0.967, 0.057, and 0.012, respectively. tm was larger but tm-ts and rp were smaller than those of allozyme markers in Pinus densiflora. These values were similar to those of microsatellite markers in other pine species. The optimal pollen dispersal model from TwoGener was the normal dispersal model with the effective density of 220 trees/ha and its level of genetic differentiation in pollen pool structure (Φft) was 0.021. The average radial distance of pollen flow (δ ) was calculated as 11.42 m, but no correlation between the pairwise-Φft and the geographical distance among mother trees was at Mantel test (r = -0.141, P > 0.05). Although the effective pollen dispersal in the population seems to be restricted, the amount of genetic variation might be maintained in each generation without a loss of genetic diversity. It might be because the genetic diversity in pollen pool was high but the genetic difference between pollen donors was small under the complete random mating condition in the Pinus densiflora population in Buan.