Application of genomics to molecular breeding of wheat and barley

In wheat and barley, several generations of selectable molecular markers have been included in the genetic maps; and a large number of qualitative and quantitative traits were located in the genomes, some of which are being routinely selected in marker-assisted breeding programs. In recent years, a large number of expressed sequence tags (ESTs) have been generated for wheat and barley that have been used for development of functional molecular markers, preparation of transcript maps, and construction of cDNA arrays. These functional genomic resources combined together with new approaches such as expression genetics, association mapping, allele mining, and informatics (bioinformatic tools) possess potential to identify genes responsible for a trait and their deployment in practical plant breeding. High costs currently limit the implementation of functional genomics in breeding programs. The potential applications together with some examples as well as challenges for applying genomics research in breeding activities are discussed. Genomics research will continue to enhance the efficiency and precision for crop improvement but will not replace conventional breeding and evaluation methods.