Chapter 9 - Genomics

Abstract

This chapter outlines the history of potato molecular genetics and the notable recent advances in potato genomics and development of genomic resources made to date. Genetical research in potato is hampered by its high levels of heterozygosity and autotetraploidy and that it suffers acutely from inbreeding depression. To counter this problem, most genetic mapping in potato is performed in diploid populations produced by the crossing of heterozygous diploid parents. More recent map-based cloning efforts have had the concomitant effects of facilitating the development of genomic resources for potato, such as large-insert genomic libraries and localized physical maps. More latterly, there has been the development of considerable quantities of expressed sequence tag (EST) data, facilitating the availability of potato microarrays for gene expression studies. In summary, potato genomics has really “taken off” since the start of the new millennium, and potato is now equal to almost any other crop plant in terms of the genome resources available to those that work on the world's fourth most important crop plant. Gene isolation covers early gene cloning and expression studies, map-based gene isolation and use of candidate gene approaches for gene isolation. Structural genomic resources cover large-insert genomic libraries and expressed sequence tag resources. Analysis of potato gene expression, microarrays, functional genomic resources, toward a genome-wide physical map and a potato genome sequence, proteomics and metabolomics and genomic databases are also covered.