[Studies on the megasporogenesis and microsporogenesis and the development of their female and male gametophyte in Magnolia biloba].
The anther of Magnolia biloba is tetrasporangiate with glandular tapetum, which consists of one or two layers of cells. Cytokinesis during meiosis of its microspore mother cell is modified simultaneous type, and the microspore tetrads are isobilateral. Mature pollen grains are two-celled. Tetrad cells and microspores are irregularly shaped during the microsporogenesis. There were two ovules on the ventral surface of unicarpellate ovary wall. Ovules were anatropous, bitegmnous and crassinucellar. Archesporial cell was one cell and differentiated from cell in the second layer beneath epidermis. The development of the embryo sac conformed to the polygonum type. The embryological characteristics of Magnolia biloba are very similar to those of other species in Magnoliaceae. The megasporogenesis and microsporogenesis and the development of their female and male gametophyte are partially abnormal. Abnormal phenomena in the process of reproduction of Magnolia biloba causing this species to be endangered was discussed.
Wang
Li Lin
LL
School of Life Sciences, Hangzhou Normal College, Hangzhou 310036. wang_208@163.com
Hu
Jiang Qin
JQ
Pang
Ji Liang
JL
Xiang
Tai He
TH
D056130:Gametogenesis, Plant / Q000502:physiology*; D031566:Magnolia / Q000166:cytology* / Q000502:physiology; D008853:Microscopy; D056771:Ovule / Q000166:cytology* / Q000502:physiology; D011058:Pollen / Q000166:cytology* / Q000502:physiology