Molecular markers: Implementation in crop plant breeding for identification, introgression and gene pyramiding

Over the past decades, wide theoretical and practical experience has been obtained in the application of DNA markers for the investigation of plant genetic diversity, the construction of molecular genetic maps, the mapping of genes and quantitative trait loci, and the employment of molecular marker technologies in the development of commercial cultivars and breeding of crop lines. To date, the main practical application of molecular markers is related to germplasm characterization, introgression and the pyramiding of genome fragments associated with agronomically important traits controlled by major genes. The contribution of new technologies to the selection of traits with multigenic inheritance is still insignificant. Despite considerable progress in plant molecular genetics and genomics methods and great interest in new technologies among breeders, there are a large number of constraints affecting the implementation of new technologies in breeding practice. This article considers the potential application of DNA markers in the breeding of crop plants and the benefits and limitations of the use of marker-assisted technologies in comparison with conventional plant breeding methods.