Comparison of Rapd Linkage Maps Constructed for a Single Longleaf Pine from Both Haploid and Diploid Mapping Populations

Considerable concern has been voiced regarding the reproducibil i ty/transferabil i ty of RAPT) markers across different genetic backgrounds in genetic mapping experiments. Therefore, separate gametic subsets (mapping populations) were used to construct individual random amplified polymorphic DNA (RAPD) linkage maps for a single longleafpine (Pinuspalwtris Mill.). A haploid mapping population consisting of megagametophytic DNAs Tom 88 wind-pollinated seeds of longleafpine (clone 3-356), and a diploid population including 86 F, progeny f?om a controlled cross [IongIeafpine 3-356 (a) x slash pine H-28 (a)] were employed. Seventy-one ,&4PD primers selected for this study identified a total of 137 mapped loci in longleafpine 3-356 based on amplification of megagametophytic DNAs. Of the 137 loci useful for comparative purposes, 62 loci (45.3O%) could not be scored when DNAs of F, progeny from the controlled cross were ampliied. Of the 75 loci that were storable, 26 loci (34.7%) were fixed ixislash pine H-28, and 49 loci (65.3%) were segregating (42 l:l,‘and seven 3: 1). Comparisons were made using the 49 loci common to both the haploidand diploid-based maps. The 49 loci allowed us to determine homologous counterparts between maps. Orders were conserved for those groups containing three or more loci . Genetic distance estimates were found to vary considerably, but not in any systematic manner. Key wbrds: random amplified polymorphic DNAs (RAPDs), Pinus palusfris Mill., genetic linkage maps, megagametophytic DNA