The enormous quantitative variation in nuclear DNA, which makes up the genomes of various plant species, has puzzled botanists ever since the cell nucleus was identified as the major organelle of heredity. Though there is strong evidence that these differences in DNA mass have clear biological effects, even in the era of whole genome sequencing the forces driving and constraining genome sizes remain to a significant degree hypothetical. In part this is because reliable data, which forms the essential substrate for theoretical work, is still limited and needs extension. Moreover, despite recent major advances in the technologies of measuring genome size, botanists are still in need of adapted methods to solve problems which sometimes arise with difficult material due to variation in anatomy and chemical composition of plant organs and tissues.

The special issue intends to include both original research investigations and focused reviews covering all aspects of genome size (DNA C-values and Cx-values) in plants. Together, these will provide a broad overview of the theoretical and practical issues which are currently being addressed in the field of genome size research along with insights into recent advances and future prospects.

Potential topics include, but are not limited to:

• Technical aspects of measuring genome size (flow cytometry, densitometry; molecular methods; analysis of difficult and dried material)
• Biological standards and standardization procedures
• Nucleotype theory (cell size, cell cycle and development; role of generative polyploidy)
• The role of genome size in ecology
• Genome size and reproduction systems
• Genome size variability and evolution
• Genome size and somatic polyploidy
• Molecular biology of genome size variation
• Genome size and gene duplication
• Base content and genome size
• Taxonomic applications and implications of genome size studies
• Expanding and completing the datasets (e.g., new major taxa)
• Terminological issues (discussion forum)
• Databases of genome size and online resources

Before submission authors should carefully read over the journal's Author Guidelines, which are located at http://www.hindawi.com/journals/jb/guidelines/. Prospective authors should submit an electronic copy of their complete manuscript through the journal Manuscript Tracking System at http://mts.hindawi.com/ according to the following timetable: