Towards construction of an ultra high density linkage map for Pinus pinaster Enrique Ritter, Ana Aragonés, Torsten Markussen, Virginie Acheré, Santiago Espinel, Matthias Fladung, Sandra Wrobel, Patricia Faivre-Rampant, Sylvain Jeandroz and Jean-Michel Favre Ann. For. Sci., 59 5-6 (2002) 637-643 DOI: 10.1051/forest:2002049