CONSTRUCTION OF A RFLP GENETIC-LINKAGE MAP FOR OIL PALM (ELAEIS-GUINEENSIS JACQ)

We have developed a restriction fragment length polymorphism (RFLP) ge netic map in oil palm (Elaeis guineensis Jacq.) for use in breeding pr ogrammes. A segregating population of 98 individuals was probed with 8 4 informative low copy clones (mainly PstI genomics). This yielded 103 scorable loci, of which 97 could be linked into 24 groups of two or m ore markers (n = 16 for oil palm), encompassing a total of 860 cM. The high level of linkage between markers (95%) suggests good genome cove rage and very little segregation distortion of markers was observed. T he mapping population which was generated by the selfing of an importa nt breeding palm (A137/30), also segregated for the shell thickness ch aracter (Sh), enabling mapping of the gene conferring this major comme rcial trait. The nearest RFLP marker (pOPgSP1282) was located 9.8 cM f rom Sh in the mapping population and 6.6 cM away in a related (A137/30 x E80/29) smaller population (45 palms). Strategies for conversion of RFLP markers to a PCR format were explored and two important markers were shown to generate allelic variants following PCR amplification an d restriction digestion of PCR products. The application of this map t o oil palm breeding programmes is discussed.