The Bayesian trees of the nuclear gene DMC1 and the chloroplast gene rps16 sequences

<p>Some plants with low fertility are morphologically intermediate between <i>Roegneria stricta</i><i> </i>and<i> Roegneria</i> <i>turczaninovii</i>, and were suspected to be natural hybrids between these species. In this study, karyotype analysis showed that natural hybrids and its putative parents were tetraploids (2n = 4x = 28). Meiotic pairing in natural hybrids is more irregular than its putative parents. Results of genomic <i>in situ</i> hybridization and fluorescence <i>in situ</i> hybridization indicate that natural hybrids contain the same genome as its putative parents. The nuclear gene DNA meiotic recombinase 1 (<i>DMC</i>1) and the chloroplast gene <i>rps</i>16 of natural hybrids and its putative parents were analyzed for evidence of hybridization. The results from molecular data supported by morphology and cytology demonstrated that the plants represent natural hybrids between <i>R. stricta</i><i> </i>and<i> R.</i> <i>turczaninovii</i>. The study is important understanding species evolution in the genus since it demonstrates for the first time the existence of populations of natural homoploid hybrids in <i>Roegneria. </i>The study also reports for the first time that the composition of the genomic formula of <i>R.</i> <i>turczaninovii </i>is <b>StY</b>, confirming that the current taxonomic status is correct.</p> <p> </p>