Phylogenetic implication of the chloroplast rpoC1 intron loss in the Aizoaceae (Caryophyllales)

A representative sample of 69 species from all recognized infrafamilial taxa of the family Aizoaceae (angiosperms, eudicotyledons, Caryophyllales) was surveyed for the presence/absence of the rpoC1 intron. PCR fragments of the samples fall into two size classes: a long fragment of approximately 1200 bp, and a short fragment of approximately 500 bp which was found in all samples from the tribes Drosanthemeae and Ruschieae of subfamily Ruschioideae. The length difference of about 700 bp corresponds to the length of the intron (738 bp in tobacco). Sequencing of the short fragment from Monilaria moniliformis revealed the precise excision of the intron as found in a previous study of the cactus family. It is concluded that the intron lacks in all samples from the clade including the tribes Drosanthemeae and Ruschieae of subfamily Ruschioideae, thus providing valuable PCR-based, sequence- and morphology-independent evidence for the monophyly of this lineage.