JOURNAL OF NANJING FORESTRY UNIVERSITY ›› 1983, Vol. 7 ›› Issue (03): 13-18.doi: 10.3969/j.jssn.1000-2006.1983.03.003
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Fan Ruwen Huang Jinsheng & Li Yongjing(Department of Forestry)
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Abstract: 1 . Stamens are at their late stage of sporogenous tissue during the winter. Microsporogenesis follows the angiosperm pattern as usual. Anthers are tetradymous. The fully developed cell wall of the anther consists of four layers. When maturing, the cell of epidermis incteases in size and forms fibrous thickenings. The medial layer and endothecium are permanent. The cell of tapetum is usually binucleated. The glandular tapetum begins disintegrating at the tetrad stage. The formation of microspote follows the synchronous type. The tetrads are mostly the tetrahedron. Pollen grains are two-celled when shedding.2 . Under the scanning electron microscope, pollen grains of two-cells are mostly round. The surface of exine of the pollen grain is clouds-like, having small pores.3 . The ultrastructure of pollen grains involves the following main features. The wall of the pollen grain has an inline and a two-layer exine (inner and outer exine). The generative cell at this stage is surrounded by a wall of callose. Most part of the generative cell is occupied by the conspicuous and elliptical nucleus. The distribution of organelles is not even in the cytoplasm. Vegetative cells with larger volume are full of cytoplasm and all kinds of organelles. These organelles include plastids, dictyosomes, mitochondria, rough endoplasmic reticuium and various forms of vacuole, etc..4 . Chloroplast occurs in the medial layer cell of the wall of pollen sacs.5 . Questions concerning the ultrastructure and development of the pollen grain are discussed in this paper.
Fan Ruwen Huang Jinsheng & Li Yongjing(Department of Forestry). ULTRASTRUCTURE AND DEVELOPMENT OF POLLEN GRAIN IN POPULUS DELTOIDES BARTR. VAR. DELTOIDES CV. HARVARD (I-63/51)[J]. JOURNAL OF NANJING FORESTRY UNIVERSITY, 1983, 7(03): 13-18.
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URL: http://nldxb.njfu.edu.cn/EN/10.3969/j.jssn.1000-2006.1983.03.003
http://nldxb.njfu.edu.cn/EN/Y1983/V7/I03/13