First nuclear DNA C-values for 18 eudicot families.
OBJECTIVE
A key target set at the second Plant Genome Size Workshop, held at the Royal Botanic Gardens, Kew in 2003, was to produce first DNA C-value data for an additional 1 % of angiosperm species, and, within this, to achieve 75 % familial coverage overall (up from approx. 50 %) by 2009. The present study targeted eudicot families for which representation in 2003 (42.5 %) was much lower than monocot (72.8 %) and basal angiosperm (69.0 %) families.


METHODS
Flow cytometry or Feulgen microdensitometry were used to estimate nuclear DNA C-values, and chromosome counts were obtained where possible.


RESULTS
First nuclear DNA C-values are reported for 20 angiosperm families, including 18 eudicots. This substantially increases familial representation to 55.2 % for angiosperms and 48.5 % for eudicots.


CONCLUSIONS
The importance of targeting specific plant families to improve familial nuclear DNA C-value representation is reconfirmed. International collaboration will be increasingly essential to locate and obtain material of unsampled plant families, if the target set by the second Plant Genome Size Workshop is to be met.
Hanson
Lynda
L
Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3DS, UK. l.hanson@kew.org
Boyd
Amy
A
Johnson
Margaret A T
MA
Bennett
Michael D
MD
D002467:Cell Nucleus / Q000235:genetics; D032461:Chromosomes, Plant; D018744:DNA, Plant; D018745:Genome, Plant; D019684:Magnoliopsida / Q000235:genetics*
D018744:DNA, Plant