A rapid improvement of the poultry industry during last thirty years was observed. Using primarily classical approaches, poultry breeders drastically decreased slaughtering age of broilers and achieved a biological limit of egg production. Along with the remarkable genetic progress numerous novel technologies have emerged elsewhere, expanding understanding the molecular structure and function of the DNA and abilities to manipulate it. The new molecular technologies, to enable poultry breeders to analyse the genotype of genetic flock using the DNA markers and developed chicken genomic map, introduce foreign and manipulated genes into the germ line of individual bird, modify the genomic make up expression of specific genes as well as produce valuable recombinant proteins using birds as bio-reactors.
A number of PCR-based methods can be used to detect the polymorphisms in plants. In this article three molecular techniques were compared: RAPD, AFLP and SSR. The marker generating procedures of two systems, AFLP and SSR, were described in details. Advantages and disadvantages each of them and their usefulness in plant breeding projects were discussed. Finally, hitherto applications of AFLP and SSR marker polymorphism analyses for genetical investigations of plants were reviewed.