CONSTRUCTION OF A GENETIC-LINKAGE MAP IN THE WILD PLANT MIMULUS USINGRAPD AND ISOZYME MARKERS

As a first step to mapping quantitative trait loci for mating system d ifferences, a genetic linkage map was generated from an interspecific backcross between Mimulus guttatus and Mimulus platycalyx. The linkage map consists of 99 RAPD and two isozyme markers. Eighty-one of these markers were mapped to 15 linkage groups, spanning 1437 contiguous cen tiMorgans, and covering 58% of the estimated genome. The genome length of Mimulus is estimated at 2474 +/- 35 cM; bootstrapping indicates th at only ca. 40 markers are needed to give an accurate estimate of geno me length. Further statistical analyses indicate that many RAPD marker s cannot be ordered with certainty and that uncertain linkage groups t end to map nonlinearly even under commonly used mapping functions. Str ategies for speeding up the mapping process for a wild species and pos sible applications of a partial linkage map in evolutionary studies ar e discussed.