XVI International Botanical Congess

The nuclear gene Floricaula/LEAFY (LFY) shows promise for phylogenetic analysis at deep levels because it is very low copy number, shows regions of high and moderate amino acid conservation, and has an ancient duplication which cuts a long branch deep in the seed plant tree. We report 11 complete and 3 partial LFY sequences, including the first from basal angiosperms and spore-bearing plants. All four gymnosperm groups show both paralogs derived from the ancient duplication. The LFY gene tree supports monophyly of extant gymnosperms at bootstraps (bs) of 99% and 100%, with Gnetales basal (bs > 85%), pine diverging next (bs >95%) and cycads related to Ginkgo. Basal angiosperms show significant resolution. Angiosperm LFYs are monphyletic and joined to ONE of the gymnosperm paralogs, AFTER the duplication, suggesting that flowering plants lost one copy of LFY.