Forward selection in a maritime pine polycross progeny trial using pedigree reconstruction.
Annals of Forest Science, 74: 21. doi: 10.1007/s13595-016-0596-8.
In link also with XYLOMIC
Vidal M, Plomion C, Raffin A, Harvengt L, Bouffier L.
Collaboration FCBA, INRA, Bordeaux University
Key message
Molecular markers were used for paternity recovery in a maritime pine (Pinus pinasterAit.) polycross trial, facilitating forward selection. Different breeding strategies for seed orchard establishment were evaluated by comparing genetic gains and diversity. This work opens up new perspectives in maritime pine breeding.
Context
Polycross mating designs are widely used in forest tree breeding to evaluate parental breeding values for backward selection. Alternatively, polycross progeny trials may be used to select the best trees on the basis of individual breeding values and molecular pedigree analysis.
Aims
This study aimed to test such a forward selection strategy for the maritime pine breeding program.
Methods
In a maritime pine polycross trial, progeny with higher breeding values for growth and stem straightness was first preselected with or without relatedness constraints. After paternity recovery, the preselected trees were ranked on the basis of their breeding values, estimated from the recovered full pedigree. Finally, the best candidates were selected with three different strategies (forward, backward, mixed) and three levels of coancestry constraints to establish a virtual clonal seed orchard.
Results
Complete pedigrees were successfully recovered for most of the preselected trees. There was no major difference in expected genetic gains between the two preselection strategies which differed for relatedness constraints. Genetic gains were slightly higher for forward selection than for classical backward selection.
Conclusion
This seminal study opens up new perspectives for using forward selection within the French maritime pine breeding program.
Keywords
Breeding strategy, Polymix breeding, Paternity recovery, SNP markers, Pinus pinaster Ait