Molecular markers, I.: Restriction fragment length polymorphism

With the development of DNA molecular marker technology, geneticists and breeders were supplied with tools for new strategies and methods in overcoming problems encountered during research and breeding. Molecular markers and related technologies are basis for linkage map construction and the analysis of the molecular and genetic background of qualitative and quantitative traits inheritance. Molecular markers that are closely linked to genes of interest have potential utility in improvement programs, although they are likely to have little or no effect in reducing the need for conventional trials across location and environments. Among the various molecular markers developed to date, Restriction Fragment Length Polymorphism (RFLP) was developed first. RFLP is the most reliable polymorphism which can be used for accurate scoring of genotypes. Using RFLP markers, genetic maps have been developed in many species. RFLP markers facilitate the selection of progenies with desirable genotypes. Analyses comprising RFLP markers are labor intensive and time consuming. In this paper, a concept of markers is discussed, with emphasis on molecular markers, restriction enzymes polymorphism, and application of RFLP markers in the mapping and marker-assisted selection. The basic principles of RFLP markers determination and their advantages and disadvantages regarding other molecular markers are briefly discussed.