ABSTRACT

The science of plant genetics traces back to Mendel’s classical studies on garden peas. Since then time, researchers have been identifying, cataloging and mapping single gene markers in many species of higher plants. Markers are “characters” whose pattern of inheritance can be followed at the morphological (e.g., Flower color), biochemical (e.g., protein and/or isozymes), or molecular (DNA) levels. This polymorphism in marker can be detected at three levels of phenotype (morphological), differences in proteins (biochemical) or differences in the nucleotide sequence of DNA (molecular). Restriction fragment length polymorphism (RFLP) was the first technology which enabled the detection of polymorphism at the DNA sequence level. In order to discuss the utility of RFLP markers in genetic mapping, it is useful to think of genetic mapping in a slightly different fashion. Since RFLPs that are positively correlated for important traits can be identified, inbred lines with RFLPs that should give high general combining ability can be selected.