ESTIMATION AND TEST FOR LINKAGE BETWEEN MARKERS - A COMPARISON OF LODSCORE AND CHI(2) TEST IN A LINKAGE STUDY OF MARITIME PINE (PINUS-PINASTER AIT)

The first step in the construction of a linkage map involves the estim ation and test for linkage between all possible pairs of markers. The lod score method is used in many linkage studies for the latter purpos e. In contrast with classical statistical tests, this method does not rely on the choice of a first-type error level. We thus provide a comp arison between the lod score and a chi(2) test on linkage data from a gymnosperm, the maritime pine. The lod score appears to be a very cons ervative test with the usual thresholds. Its severity depends on the t ype of data used.