Chinese Bulletin of Botany ›› 2003, Vol. 20 ›› Issue (05): 576-584.

• 研究论文 • Previous Articles     Next Articles

Microsporogenesis and Malegametogenesis of Larix chinensis Beissn

YU Xiao-Min ZHAO Gui-Fang   

  1. (The College of Life Science, Northwest University, Xi'an 710069)
  • Received:2002-12-28 Revised:2003-04-25 Online:2003-10-20 Published:2003-10-20
  • Contact: ZHAO Gui-Fang

Abstract: The male cone of Larix chinensis Beissn differentiates at the beginning of July. The microsporangium wall of L. chinensis comprises one epidermis, one endothecium, 2~3 middle layers, and a tapetum. The tapetum conforms to periplasmodial type. The sporogenous cell occurs in late July. The microspore mother cell is formed in early August, and its meiosis begins to occur in late August. The microspore mother cell enters into diplotene in early October, and goes through dormancy at this phase. The microspore mother cell ends dormancy in late March next year, and continues its meiosis. In the middle of April tetrad forms and microspore is released from late April to early May. After microspore’s four times continuous mitosis, the mature pollen (male gametophyte) which comprising five cells forms and begins shedding in middle May. The development of the microspore mother cell is not synchronous, and some microsporocytes begin to degenerate, resulting in the formation of a large cavity in the microsporangium.