Studies on the Morphology, Structure and Development in Magnoliaceae

摘要

Comparative biology requires extensive information on characters to provide foundations for the reconstruction of the evolution history of the plant. Basing on different characters, especially on the molecular data, different opinions on the status of Magnoliaceae were proposed continually. The boatshaped pollens with monosulcate aperture, psilate surface, perforated tectum and intermediate infratectal structures, which all occur in Magnoliaceae, are proved to be relatively derived in this family. Whorled perianth, short stamen base, plicate carpels and the condition of mostly two ovules in each carpel all are relatively specialized characters. The present study combines morphological date of pollen, sclerotesta and floral ontogeny as well, gives a synthetic analysis of them and supports that the Magnoliaceae and other groups in Magnoliales are obviously distinct. They are not the most basal but a relatively derived group. Extensive sampling and diagnostic characters collection are indeed necessary to get the better understanding of different opinions on the status of Magnoliaceae.