Chapter 2 - Genome Size Evolution in Plants

Abstract

This chapter provides an overview of the current state of knowledge concerning genome size evolution in plants. It includes a review of available data, the patterns of variation both within and among species, and higher taxa. Every cellular organism possesses a genome and genome size evolution is not limited to any one taxon, but rather is of universal biological interest. Along with animals, plants are the best studied group with regard to variation in DNA content, and have played a critical role since the earliest days of genome size study. The field of genome size research in plants may be considered to have reached “the end of the beginning.” Although the Plant DNA C-values Database includes representatives from each of the major land plant groups, the percent coverage at the species level remains very poor (generally <2%) for all but the gymnosperms. In 50 years plant genome size research has moved from simply documenting C-values and expressing confusion over the “C-value paradox” to identifying the major patterns of variation, illuminating some of the molecular mechanisms and evolutionary forces responsible, and framing a specific series of questions as part of the “C-value enigma.” With continued surveys of plant genome size and integration with other fields ranging from molecular biology to ecology, it is possible that the future will finally see the emergence of the “C-value solution(s).”