Nuclear DNA amounts in angiosperms and their modern uses - 807 new estimates

The DNA amount in the unreplicated haploid nucleus of an organism is known as its C-value. C-values differ about 1000-fold among angiosperms and are characteristic of taxa. The data are used in many biological fields, so they should be easily available. Values For 2802 angiosperm species (1 %) were estimated during 1950-1997, and five collected lists of C-values were published for reference purposes during 1976-1997. Numbers of new angiosperm C-values published recently remained high, necessitating a Further supplementary list. This paper lists DNA C-values for 807 angiosperm species from 70 original sources, including 520 (75.2 %) from sources published after 1996, and 691 for species not included in any of the previous five lists. There is a continuing need to estimate accurate DNA C-values for plant taxa, as shown in a workshop on this biodiversity topic sponsored by Annuls of Botany and held at Kew in 1997. Its key aim was to identify major gaps in our knowledge of plant DNA amounts and to recommend targets and priorities for new work to fill them. A target of estimating first C-values for the next 1 % of angiosperm species in 5 years was set. The proportion of such C-values in the present work (85.6 %) is very high, and the number being published (approx. 220 per annum) has never been exceeded. In 1997, C-values were still unknown for most (68 %) families, so a target of complete coverage was set. This paper includes first C-values for 12 families, but as less than 2 % of such values listed here targeted new families, the need to improve familial representation remains. (C) 2000 Annals of Botany Company.