Plant genome size research: a field in focus.

This Special Issue contains 18 papers arising from presentations at the Second Plant Genome Size Workshop and Discussion Meeting (hosted by the Royal Botanic Gardens, Kew, 8-12 September, 2003). This preface provides an overview of these papers, setting their key contents in the broad framework of this highly active field. It also highlights a few overarching issues with wide biological impact or interest, including (1) the need to unify terminology relating to C-value and genome size, (2) the ongoing quest for accurate gold standards for accurate plant genome size estimation, (3) how knowledge of species' DNA amounts has increased in recent years, (4) the existence, causes and significance of intraspecific variation, (5) recent progress in understanding the mechanisms and evolutionary patterns of genome size change, and (6) the impact of genome size knowledge on related biological activities such as genetic fingerprinting and quantitative genetics. The paper offers a vision of how increased knowledge and understanding of genome size will contribute to holisitic genomic studies in both plants and animals in the next decade.