Genome Sizes inHepaticaMill: (Ranunculaceae) Show a Loss of DNA, Not a Gain, in Polyploids

[摘要] Genome size (C-value) was applied anew to investigate the relationships within the genusHepatica(Ranunculaceae). More than 50 samples representing all species (exceptH. falconeri), from wild and cultivated material, were investigated. Species ofHepaticaturn out to be diploid (2n=14), tetraploid (2n=28), and a possible pentaploid. The somatic nuclear DNA contents (2C-value), as measured by flow cytometry with propidium iodide, were shown to range from 33 to 80 pg. The Asiatic and American species, often considered subspecies ofH. nobilis, could be clearly distinguished from EuropeanH. nobilis. DNA content confirmed the close relationships in the Asiatic species, and these are here considered as subspecies ofH. asiatica. Parents for the allotetraploid species could be suggested based on their nuclear DNA content. Contrary to the increase in genome size suggested earlier forHepatica, a significant (6%–14%) loss of nuclear DNA in the natural allopolyploids was found.

[学科分类] 植物学