EVOLUTION OF GENOME SIZE IN ALLIUM (ALLIACEAE)

The 4C DNA amounts of 86 species from Allium subgg. Allium, Rhizirideu m Bromatorrhiza, Melanocrommyum, Caloscordum and Amerallium show a 8.3 5-fold difference ranging from 35.60 pg (A. ledebourianum, 2n = 16) to 297.13 pg (A. validum 2n = 56). At diploid level the difference is 3. 57-fold between A. ledebourianum (35.60 pg) and A. ursinum (127.14 pg) . This shows that a significant loss and/or gain of DNA has occurred d uring evolution. On average subgg. Rhizirideum and Allium have less DN A amount than subgg. Melanocrommyum and Amerallium. The distribution o f nuclear DNA amounts does not show discontinuous pattern and regular groups. The evolution of genome size has been discussed in relation to polyploidy and genomes, heterochromatin, adaptive changes in morpholo gical characteristics, phenology and ecological factors, and infragene ric classification.