• Polyploidization and chromosomal rearrangements are recognized as major forces in plant evolution. Their role is investigated in the disjunctly distributed northern hemisphere Hepatica (Ranunculaceae). • Chromosome numbers, karyotype morphology, banding patterns, 5S and 35S rDNA localization in all known species were investigated and interpreted in a phylogenetic context established from nuclear internal transcribed spacer (ITS) and plastid matK sequences. • All species had a chromosome base number of x = 7. The karyotype was symmetric and showed little variation among diploids with one locus each of 5S and 35S rDNA, except for interpopulational variation concerning 35S rDNA loci number and localization in H. asiatica. Tetraploids exhibited chromosomal changes, including asymmetry and/or loss of rDNA loci. Nuclear and plastid sequences resulted in incongruent topologies because of the positions of some tetraploid taxa. The diversification of Hepatica occurred not earlier than the Pliocene. • Genome restructuring, especially involving 35S rDNA, within a few million yr or less characterizes evolution of both auto- and allopolyploids and of the diploid species H. asiatica, which is the presumptive ancestor of two other diploid species.
1 September 2018 in Journal of Asia-Pacific Biodiversity
This study was undertaken to better understand Allium infrageneric taxonomy, character evolution, species diversification, and patterns of radiation in disjunct species between the New and Old World using morphological and molecular data. Taxonomic sampling focused on northeastern Asian (mainly Korean and northeastern Chinese) and representative disjunct northern North American (Canadian) species. Pistil and seed testa morphology was investigated using light and scanning electron microscopy, respectively. These characters were useful to assess degree of relationship at different taxonomic levels in Allium. Phylogenetic studies included nrDNA ITS and cpDNA trnL–trnF sequence data analyzed using maximum parsimony approaches. Our molecular phylogeny recovers a similar topology to that published in recent studies and confirms three major evolutionary lines and patterns of radiation regarding the ancestors of subgenera Amerallium and Anguinum in the genus. The northeastern Asian and northern North American disjunction in this genus is inferred to be the result of multiple intercontinental migrations. Seed testa sculpture attributes in combination with seed shape provide key characters to distinguish Allium’s major clades in the molecular phylogeny. The two types of ovarian processes, basal hood-like and apical crest-like in disjunct Old and New World species, respectively, are newly derived characters in each continent. Most infrageneric Allium groups are monophyletic, while subgenus Cepa is polyphyletic.
Lack of Arabidopsis‐type T3AG3 telomere sequences has recently been reported for the majority of investigated taxa of the monocot order Asparagales. In order to investigate this phenomenon in more de...
This paper discusses identifying Important Plant Areas (IPAs) in one of the most densely populated regions of Central Asia—the Fergana valley. The recognition of IPA sites is an attempt to introduce new ways of conserving local plant diversity with a high concentration of endemic species in Central Asia, where conservation methods of the former Soviet Union still prevail. The research revealed the current state and geography of many rare species and enriched the flora of Uzbekistan and Kyrgyzstan with several rare species. The second IPA is the transboundary territory of the Fergana valley, uniting the southern spurs of the Chatkal range and the Ungortepa-BozbuToo massif. We documented the distribution of 62 species in the IPAs under the sub-criteria of Plantlife International. Our study aimed at continuing studies on the IPAs in this region, addressing specific conservation challenges, such as conserving national endemics and endangered species that grow outside protected areas and GIS mapping of endemic species.