Plant Diversity ›› 2008, Vol. 30 ›› Issue (05): 549-556.doi: 10.3724 SP.J.1143.2008.07292

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Mega- and Microsporogenesis and Development of Female and Male
Gametophytes of Michelia coriacea (Magnoliaceae), a Globally Critical Endangered Plant in South-East Yunnan of China

ZHAO Xing-Feng1 , 2 , SUN Wei-Bang1, YANG Hua-Bin3 , LI Wan-Cheng4   

  1. 1 Kunming Botanical Garden , Kunming Institute of Botany , Chinese Academy of Sciences, Kunming 650204 , China; 2 Graduate University of Chinese Academy of Sciences, Beijing 100049 , China ; 3 The Seedling Station of Wenshan Forest Bureau , Wenshan 663000 , China ; 4 Defu Nature Reserve, Baise 533000 , China
  • Received:2007-12-13 Online:2008-10-25 Published:2008-10-25

Abstract: The mega- and microsporogenesis and development of male and female gametophytes of Michelia coriacea were investigated using paraffin section method . The anther of the species was tetrasporangiate and its anther wall was composed of 5 - 7 layers cells, and the tapetum belonged to glandular type. In the meiosis of microsporocyte, cytokinesis was modified simultaneous type. The tetrads were tetrahedral, decussate and sometimes were anomalous type. Mature pollen grain was twocelled. The ovule was anatropous, bitegmic, and crassinucellar. The megaspore mother cell undergone meiotic divisions and developed into a linear type of tetrads. The chalazal megaspore of the tetrad was functional. The functional megaspore underwent three successively nuclear divisions to give rise to eight-nucleate embryo sac which was Polygonum Type. The high percentage of abortion could be observed in process of megaspore and microspore genesis and the development of gemetophytes. The abnormality in the reproductive development of this species might be the main cause of its extremely low seed set .

Key words: Michelia coriacea

CLC Number: 

  • Q 944