The pollination of zygogynum (winteraceae) by a moth, sabatinca (micropterigidae): an ancient association?

The primitive and vesselless angiosperm Zygogynum (Winteraceae), which is restricted to New Caledonia, is pollinated by a moth, Sabatinca (Micropterigidae). Fossil records of both the moth and the plant families extend to the Early Cretaceous. Adult Sabatinca have grinding mandibles and usually feed on the spores of ferns and on pollen. The insects use the flowers as mating sites and eat the pollen which is immersed in a dense pollenkitt. This mode of pollination in which flowers serve as mating and feeding stations with floral odors acting as cues may have been common in the early evolution of flowering plants.

Molecular phylogeny of the Magnoliaceae: the biogeography of tropical and temperate disjunctions

The boreotropical flora concept suggests that relictual tropical disjunctions between Asia and the Americas are a result of the expansion of the circumboreal tropical flora from the middle to the close of the Eocene. Subsequently, temperate species diverged at high latitudes and migrated to other continents. To test this concept, we conducted a molecular phylogenetic analysis (using cpDNA) of the Magnoliaceae, a former boreotropical element that currently contains both tropical and temperate disjuncts. Divergence times of the clades were estimated using sequences of matK and two intergenic regions consisting of psbA-trnH and atpB-rbcL. Results indicate the tropical American section Talauma branched first, followed by the tropical Asian clade and the West Indies clade. Within the remaining taxa, two temperate disjunctions were formed. Assuming the temperate disjunction of Magnolia acuminata and Asian relatives occurred 25 mya (late Oligocene; based on seed fossil records), section Talauma diverged 42 mya (mid-Eocene), and tropical Asian and the West Indies clades 36 mya (late Eocene). These events correlate with cooling temperatures during the middle to late Eocene and probably caused the tropical disjunctions.

Cloning and sequence determination of the chloroplast psbA gene in Magnolia pyramidata (Magnoliales; Magnoliaceae)

The full length gene encoding the D1 protein of photosynthesis (psbA) has been cloned and sequenced from Magnolia pyramidata (Magnoliaceae). Despite considerable investigation into psbA structure and function in many algal lineages and a few agricultural plants, there has been little effort invested toward characterizing a broader range of plant psbA genes. This is the first report of a psbA gene sequence from a primitive angiosperm. The DNA and deduced amino acid sequences maintain high overall conservation with other taxa, suggesting a role for psbA in broad based angiosperm phylogenetic reconstruction.