Popis: |
The mitochondrial genome of Liriodendron tulipifera exhibits many ancestral angiosperm features and a remarkably slow evolutionary rate, while mitochondrial genomes of other magnoliids remain yet to be characterized. We assembled nine new mitochondrial genomes, representing all genera of perianth-bearing Piperales, as well as for a member of the sister clade: three complete or nearly complete mitochondrial genomes from Aristolochiaceae and six additional draft assemblies including Thottea, Asaraceae, Lactoridaceae, and Hydnoraceae. For comparative purpose, a complete mitochondrial genome was assembled for Saururus, a member of the perianth-less Piperales. The average number of short repeats (50–99 bp) was much larger in genus Aristolochia than in other angiosperm mitochondrial genomes, and approximately 30% of repeats ( T:A substitutions of all other investigated angiosperm groups. Our study reports the first mitochondrial genomes for Piperales and uses this new information for a better understanding of the evolutionary patterns of magnoliids and angiosperms in general. |