摘要
Floral ontogeny is described in two species of genus Magnolia （Magnollaceae）, Magnolia alboserlcea Chun et C. Tsoong, and M. amoena Cheng, representing subgenus Magnolia and subgenus Yulani In Magnolia, by using scanning electron microscope （SEM）. The sequence of Initiation of floral organs Is from proximal to distal. The three distinct outermost and middle organs are Initiated in sequence, but ultimately form a single whorl, thus their ontogeny Is consistent with a sepal Interpretation. The last three tepals （petals） alternate with the preceding tepal whorl. The members of androeclum and gynoeclum arise spirally, although the androecium shows some Intermedlacy between a spiral and whorled arrangement. The carpel prlmordia initiate in group of four to five. The order of stamen Initiation within each tier Is not determined. The floral ontogeny Is remarkably homogeneous between the subgenus Magnolia and subgenus Yulani that does not support the resuming of genus Yulani.
Floral ontogeny is described in two species of genus Magnolia （Magnollaceae）, Magnolia alboserlcea Chun et C. Tsoong, and M. amoena Cheng, representing subgenus Magnolia and subgenus Yulani In Magnolia, by using scanning electron microscope （SEM）. The sequence of Initiation of floral organs Is from proximal to distal. The three distinct outermost and middle organs are Initiated in sequence, but ultimately form a single whorl, thus their ontogeny Is consistent with a sepal Interpretation. The last three tepals （petals） alternate with the preceding tepal whorl. The members of androeclum and gynoeclum arise spirally, although the androecium shows some Intermedlacy between a spiral and whorled arrangement. The carpel prlmordia initiate in group of four to five. The order of stamen Initiation within each tier Is not determined. The floral ontogeny Is remarkably homogeneous between the subgenus Magnolia and subgenus Yulani that does not support the resuming of genus Yulani.
基金
Supported by the National Natural Science Foundation of China （30370108 and 30000011） and the Guangdong Provincial Natural Science Foundation of China （5006764）. Acknowledgements The author appreciated Dr Paula Rudall and Mrs Chrissie Prychid in Royal Botanic Gardens, Kew for their supervision and kind help in the laboratory.
