Phylogeny Of The Polypodiaceae In China

Polypodiaceae is the certain lines of evolution of the more advanced groups of ferns. The phylegeny of the genus in Polypodiaceae is not exactly known. We use spore morphology,gemetophyte development and molecular phylogeny to understand the evolution and phylogeny of the Polypodiaceae:â‘ Spores of 54 species,1 varieties and 1 forma in 19 genera of the Polypodiaceae from China and 6 species in 1 genus overseas were examined under scanning electron microscope (SEM). The results show that: the spores of Polypodiaceae are monolete, bilaterally symmetric, elliptic in polar view and reniform or fabiform in equator view. The thick exspore is psilate, verrucate, undulate or rugulate. The thin perispore is tuberculate, granulate or psilate with ornaments. The spores of Polypodiaceae are divided into six types based on surface ornamentations: verrucate,tuberculate,granulate,undulate,rugulate and psilate with ornaments.â‘¡The morphology of gametophyte development about 13 species,1 varieties in 11 genera of the Polypodiaceae from China were examined under microscope. The results show that: Germination is preceded by swelling of the contents of spores, form a rhizoid initial first, perpendicular to the rhizoid geminate a primary cell. The spore germination is Vittaria-type. There are 2~12 cells in the filaments, the morphology of the filament cell is barrel-shape,round barrel-shape and oblate barrel-shape. The terminal cell of the germ filament divides by two oblique divisions form a wedge-shaped cell. An obconical meristematic cell is formed by two oblique divisions when the thallus 3~5 cells broad sometimes. The thallus is ligulate,spatula or oblate. The trichomes exist when the meristem is formed most of the time. The prothallial development is Adiantum-type or Drynaria-type. The morphology of adult prothallus is Cordate-thalloid bilaterally symmetric, generally broader than long, with the median midrib is thin. The wings are elongate upwards,spread out or interleaving entad. There is a dissepiment in the base of the reizoid. The archegonial neck is columnar and curved away from the apex of the prothallus. The archegonial neck is compose of four rows of cells, 4~7 layers. Antheridium is subglobose or Funnel-shaped. The cap cell is round, antheridial dehiscence is by collapse of the cap cell.â‘¢The relationships of 17 species and 1 variety in 10 genera and 35 species in 13 genera from NCBI of the Polypodiaceae based on rbcL and rps4-trnS gene sequence are investigated. Complete alignment is done by ClustalX1.83 to arrange the multiple sequences. We make phylogeny trees by use of the PHYLIP(Version3.66)in Neighbor joining,Maximum parsimony and Maximum likelihood method.The species in the same genera are similar. There are probably 4 evolution routes in the family according to phylogeny of genera. The three evolution routes are also have some relationships between each other beside the route of Polypodioideae. Polypodioideae is maybe a single part in the phylogeny. This paper also discussed the relationships between the Polypodiaceae and its allied families.