Background And Aims: Rubus ser. Glandulosi provides a unique model of geographical parthenogenesis on a homoploid (2n = 4x) level. We aim to characterize evolutionary and phylogeographical patterns in this taxon and shed light on the geographical differentiation of apomicts and sexuals.
View Article and Find Full Text PDFAsexual organisms often differ in their geographic distributions from their sexual relatives. This phenomenon, termed geographic parthenogenesis, has long been known, but the underlying factors behind its diverse patterns have been under dispute. Particularly problematic is an association between asexuality and polyploidy in most taxa.
View Article and Find Full Text PDFThe species-rich and widespread genus F. H. Wiggers, 1780 (Asteraceae subfamily Cichorioideae) is one of the most taxonomically complex plant genera in the world, mainly due to its combination of different sexual and asexual reproduction strategies.
View Article and Find Full Text PDFBackground And Aims: Rubus subgenus Rubus is a group of mostly apomictic and polyploid species with a complicated taxonomy and history of ongoing hybridization. The only polyploid series with prevailing sexuality is the series Glandulosi , although the apomictic series Discolores and Radula also retain a high degree of sexuality, which is influenced by environmental conditions and/or pollen donors. The aim of this study is to detect sources of genetic variability, determine the origin of apomictic taxa and validate microsatellite markers by cloning and sequencing.
View Article and Find Full Text PDFNew species are generated by many means, among which hybridization plays an important role. Interspecific hybrids can form isolated evolutionary units, especially when mechanisms increasing viability and fertility, like polyploidy and apomixis, are involved. A good model system to study reticulate evolution in plants is Rubus subgen.
View Article and Find Full Text PDFRubus subgen. Rubus includes common European species with highly complicated taxonomy, ongoing hybridisation and facultative apomixis. Out of approximately 750 species recognised in Europe, only 3 diploid sexual species are known, along with numerous apomictic brambles that are highly connected to polyploidy.
View Article and Find Full Text PDFDandelions (genus Taraxacum) comprise a group of sexual diploids and apomictic polyploids with a complicated reticular evolution. Apomixis (clonal reproduction through seeds) in this genus is considered to be obligate, and therefore represent a good model for studying the role of asexual reproduction in microevolutionary processes of apomictic genera. In our study, a total of 187 apomictic individuals composing a set of nine microspecies (sampled across wide geographic area in Europe) were genotyped for six microsatellite loci and for 162 amplified fragment length polymorphism (AFLP) markers.
View Article and Find Full Text PDFCytokinins (CKs) are plant hormones affecting numerous developmental processes. Zeatin and its derivatives are the most important group of isoprenoid CKs. Zeatin occurs as two isomers: while trans-zeatin (transZ) was found to be a bioactive substance, cis-zeatin (cisZ) was reported to have a weak biological impact.
View Article and Find Full Text PDFBackground And Aims: Polyploidization plays an important role in the evolution of many plant genera, including Koeleria. The knowledge of ploidy, chromosome number and genome size may enable correct taxonomic treatment when other features are insufficient as in Koeleria. Therefore, these characteristics and their variability were determined for populations of six central European Koeleria taxa.
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