Identification of QTLs controlling growth, chemical and physical wood property traits in Pinus pinaster (Ait.)

Growth characteristics and wood quality represent important criteria in forestry. Dissection of these quantitative traits into single genetic components using molecular markers and linkage maps, provide useful information for breeders about the genetic determinism of polygenic traits. In order to apply marker assisted breeding in early selection procedures, QTL analyses for growth traits and physical and chemical wood properties were performed in a Pinus pinaster progeny. A high-density linkage map of P. pinaster was used for this purpose. No significant correlations were found between wood quality and growth traits. A total of 10 QTLs were detected for the growth traits height and diameter and 40 QTLs for seven wood parameters including alpha -cellulose content, lignin content, pulp yield, brightness and wood densities. QTLs were spread across the genome. The percentages of phenotypic variances explained by individual QTLs ranged from to 4.3% to 18.4% and the sum of trait-specific QTLs explained 20 to 53% of the total variance. The usefulness of marker assisted selection for wood quality traits is discussed.