Embryological Studies on Narcissus tazetta var.chinensis  

作　　者：Ge Lili Wu Jian Chen Linjiao Wang Rui Tian Huiqiao 

机构地区：[1]School of Life Sciences,Xiamen University,Xiamen 361005,China

出　　处：《Frontiers in Biology》2006年第1期18-22,共5页生物学前沿（英文版）

基　　金：supported by the Fujian Natural Sciences Foundation (No.F0210009).

摘　　要：Chinese narcissus(Narcissus tazetta var.chinensis Roem)blooms but has no seeds.Embryological studies on the species were conducted to discover the causes of its sterility.Its anther wall is composed of four layers of cells,and its tapetum is of the secretory type.The cytokinesis of microspore mother cells is of the successive type,and the tetrad is tetrahedral.During meiosis of microspore mother cells,some chromosomes lagged,and several micronuclei were found in tetrads.Only 27.7%of the pollen grains contained full cytoplasm,and 1.3%of them germinated in culture medium.No pollen grain,however,could germinate on the stigma.The ovary is trilocular with axile placenta,and the ovules are bitegmic,tenuinucellate,and anatropous.Its embryo sac is of the polygonum type.Most embryo sacs degenerated,and only about 4.5%of the ovules contained a normal embryo sac with an egg cell,two synergids,three antipodal,and a central cell containing two polar nuclei.One reason for the sterility of Chinese narcissus is the abnormality of microsporogenesis and megasporogenesis,in which only a few functional pollen grains and embryo sacs are produced.The other reason is that the pollen grains cannot germinate on the stigma.

关 键 词：EMBRYOLOGY MEGASPOROGENESIS MICROSPOROGENESIS Narcissus tazetta var.chinensis Roem 

分 类 号：Q94[生物学—植物学]