POLLEN MORPHOLOGY OF SEVERAL SPECIES FROM MICHELIA(MAGNOLIACEAE)

Pollen morphology of 4 species from Michelia are similar under LM.Under SEM,the sculpture of M.champaca is perforate,M.balansae and M.foveolata are foveolate.While M.skinneriana has rugulose,comparatively coarse sculpturing.Under TEM,the exine of the4 species can be distinguished into tectum,baculum and footlayer.The baculum structure appears to be primitive in M.champaca,but that of M.foveolata shows comparatively advanced features.Evolution of pollen morphology can reflex the systematic evolution of taxonomic group to a certain extent.