石刁柏大孢子发生和发育的细胞学观察

石刁柏的大孢子母细胞发生于花蕾直径约1～2mm时期。大孢子母细胞体积为15×16×21μ。后经减数分裂形成四分孢子,呈直线排列,具极性,合点端的大孢子为功能大孢子,其他三个大孢子退化。由功能性大孢子发育为胚囊。其发育途径为典型的单子叶植物类型——蓼形。石刁柏大孢子发生和发育的细胞学观察是取戮破珠被的胚珠,用果胶酶和纤维素酶混合液处理,分离胚囊,在光学显微镜下附加IF550绿色干涉荧光滤片,进行观察和摄影。

Cytological Observation on Macrosporogenesis and Development in Asparagus Officinalis

As the flower bud of Asparagus officinalis grows to about 1-2 mm in diameter, the inacrospore mother cell stage is presented. The macrosporocyte is larger ( 15~16 μ wide by 21 μ long) than the surround nucellar and then arises as megaspore cell tetrad stage by meiotic division. Tetrad arrangement is linear.The subchalazal megaspore is functional, the other three degenerate. The chalazal megaspore in the tetrad develop into embryo sac in polygonum type. The macrosporocyte, megaspore and embryo sac are isolated by means of enzymatic maceration technique with stabbed ovules of Asp. officinalis, observed under the light microscope with filter IF550.