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

B J M Zonneveld

doi:10.1155/2010/758260

Abstract

Genome size (C-value) was applied anew to investigate the relationships within the genus Hepatica (Ranunculaceae). More than 50 samples representing all species (except H. falconeri), from wild and cultivated material, were investigated. Species of Hepatica turn out to be diploid (), tetraploid ( ), 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 of H. nobilis, could be clearly distinguished from European H. nobilis. DNA content confirmed the close relationships in the Asiatic species, and these are here considered as subspecies of H. asiatica. Parents for the allotetraploid species could be suggested based on their nuclear DNA content. Contrary to the increase in genome size suggested earlier for Hepatica, a significant (6%–14%) loss of nuclear DNA in the natural allopolyploids was found.

Highlights

Phylogenies based on restriction sites of chloroplast and ribosomal DNA and morphological and cytological variations indicate that the genus Hepatica Mill. should be subsumed within genus Anemone (L.) [1]
Dezhi and Robison [6] regarded H. yamatutae Nakai as synonymous with H. henryi (Oliv.) Steward and H. asiatica Nakai to be a variety of H. nobilis Schreb
The classical taxonomic traits based on morphology and geographical proximity are here supplemented with data on nuclear DNA content

Summary

Introduction

Phylogenies based on restriction sites of chloroplast and ribosomal DNA and morphological and cytological variations indicate that the genus Hepatica Mill. should be subsumed within genus Anemone (L.) [1]. There are numerous gaps in the available molecular data [2]. it seems better to refrain from creating new generic or infrageneric taxa in Anemone and keep the classical concept of Hepatica [3]. The genus comprises about 12 species disjunctly distributed in the temperate zones of Europe, North America, and East Asia. They can be arranged in two sections: the mainly diploid section Hepatica with 2n = 14 and the mainly polyploid section Angulosa (Ulbr.) Nakai with 2n = 28. More than 50 different accessions representing all known species except H. falconeri (Thomson) Steward, and commonly available hybrids, were measured in an attempt to better understand the infrageneric relationships and to gain insight into the origin of some of the cultivars

Results

Discussion

Conclusion