QUANTITATIVE NUCLEAR-DNA CHANGES IN ELEUSINE (GRAMINEAE)

2 C nuclear DNA amounts were determined in 30 collections belonging to 10 species of Eleusine. About a 2.5-fold variation in genome size is evident in the genus. The 2 C DNA amount in the diploid species ranged from 2.50 pg in E. verticillata to 3.3 5 pg in E. intermedia. In contrast, the tetraploid species showed a range from 4.95 pg in E. africana to 6.13 pg in E. floccifolia. At intraspecific level 10 collections of E. coracana, 6 of E. indica, 4 of E. africana, 2 of E. tristachya, and 2 of E. kigeziensis did not show any significant variation. However, 2 collections of E. floccifolia, connected with polyploidy, displayed about 90% variation. Polyploid species showed approximately double the genome size of that of their corresponding diploids. An evolutionary increase in DNA amount is evident in E. coracana during the course of its origin and domestication from E. africana.