ABSTRACT
This chapter shows that random amplified polymorphic DNAs (RAPD) markers have greatly facilitated the development of linkage maps in several diverse crops. However, the main purpose of linkage mapping was viewed more as a bookkeeping device by which the various genes could be ordered and predictions regarding recombination frequencies could be made. The one new approach that appears to have immediate potential even for those breeders working with crops of secondary economic importance is that based on the amplification of DNA fragments using a temperature stable DNA polymerase and arbitrary primers. A set of molecular markers would be useful in herbaceous crops such as lentil, sunflower, lupin, and cucumber. The major questions that must be answered before RAPDs can be accepted as the markers of choice concern their level of polymorphism in a variety of crops, problems associated with their dominant nature, and whether a extensive set of RAPD markers can be assembled faster than RFLPs can be developed.
