Selfing and sibship structure in a two-cohort stand of maritime pine (Pinus pinaster Ait.) using nuclear SSR markers uri icon

abstract

  • The genetic relatedness between pairs of trees was analyzed in an adult stand of maritime pine with abundant advanced natural regeneration using three highly polymorphic microsatellites (EP>90%). Only five possible self-pollinated offspring were found, thus meaning a maximum selfing rate based on dispersed progeny of 3.8%. Likelihood ratios were used to detect sib relationships in both mature trees and natural regeneration. The percentage of half-sib and full-sib links in the adult trees was 19.09% and 1.82%, respectively, thus indicating a low level of genetic relatedness due to sib relationships (approximate to3%). Similar results were obtained for the natural regeneration but with a higher percentage of full-sibs (2.37%) and a greater family size. A high amount of pollen gene flow from outside the plot is suggested to explain the low genetic relatedness found. Collection of seedlots in this stand seems adequate as a low level of inbreeding is expected.

publication date

  • 2003
  • 2003