Phylogenetic inference and peristome evolution in haplolepideous mosses,focusing on Pseudoditrichaceae and Ditrichaceae s. l. |
| |
| Authors: | Vladimir E Fedosov Alina V Fedorova Alexander E Fedosov Michael S Ignatov |
| |
| Affiliation: | 1. Geobotany Department, Biological Faculty, Lomonosov Moscow State University, Moscow, Russia;2. Belozersky Institute of Physico‐Chemical Biology, Lomonosov Moscow State University, Moscow, Russia;3. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences Moscow, Russia;4. Tsitsin Main Botanical Garden, Russian Academy of Sciences, Moscow, Russia |
| |
| Abstract: | Pseudoditrichum mirabile, the only species of Pseudoditrichaceae, has been known for a long time from a single collection from the Canadian Arctic. Its systematic position remained enigmatic due to similarity in gametophyte structure with Ditrichaceae, a family that has simple peristomes, whereas the peristome in Pseudoditrichum is double. Due to this difference, Pseudoditrichum was classified in either Funariales or Bryales. A recent discovery of this species in the Anabar Plateau in northern Siberia has allowed its phylogenetic position to be tested based on plastid rps4 and rbcL and mitochondrial nad5 sequences. The results of this research reject the earlier hypotheses. Instead, the molecular analysis resolves Pseudoditrichum in a clade with Chrysoblastella chilensis (formerly Ditrichaceae) in the haplolepideous lineage. The peristome of Pseudoditrichum is of a previously unknown type with a fully developed exostome and hyaline endostome elements opposite the exostome teeth, based not on the 4:2:4 peristomial formula, but on 4:2:3. Double peristomes of the same type, albeit rather strongly reduced, occur in Catoscopium, Chrysoblastella, Distichium and Ditrichum flexicaule. The polyphyly of Ditrichaceae is confirmed by molecular phylogenetic analysis, and Ditrichum flexicaule and D. gracile are segregated into the new genus Flexitrichum and family Flexitrichaceae. An independent status of the recently resurrected family Distichiaceae is supported, and segregation of Chrysoblastella and Saelania into new monospecific families is proposed. |
| |
| Keywords: | Bryopsida
Chrysoblastella
Distichiaceae
Ditrichum flexicaule
nad5
phylogeny
Pseudoditrichum
rps4
Saelania
taxonomy |
|
|
