入侵杂草美洲商陆大小孢子的形成和雌雄配子体的发育

The Megasporogenesis and Microsporogensis of Invasive Weeds Phytolacca americana and Formation of Its Male and Female Gametophyte

为了探究外来种美洲商陆的入侵性,采用石蜡切片方法研究了美洲商陆不同发育阶段的花器官结构,结果表明:美洲商陆胚珠生长于心皮内侧靠轴的地方,属于非典型的基底胎座,倒生胚珠,双珠被,厚珠心型。次生造孢细胞发育成大孢子母细胞。大孢子母细胞经减数分裂形成3个大孢子,合点端的大孢子发育为胚囊,胚囊蓼型。小孢子母细胞减数分裂为同时型,四分体排列方式为四面体型,成熟花粉是2-细胞型。这与本地种有着极大的相似性,这可能是美洲商陆入侵后对环境适应的结果。

In order to discuss the invasiveness of Ph.americana,an anatomical study was conducted on the dif-ferent development stages of the Ph.americana flowers organs by the common plant paraffin section.The results showed that the ovule of Ph.americana was grown near the axis on the inside of carpel and belongs to a typical bas-al placentation,pour ovule,double integument,thick bead heart type.The secondary sporogenous cells developed in-to a megaspore mother cells.Megaspore mother cells meiosis developed into three megaspore,the whole point of the megaspore development for embryo sac,and embryo sac was contents type.The meiosis of microspore mother cells was the same time type,a tetrad tetrahedron form arrangement,and mature pollen was 2-cell type.It was higher sim-ilarity with native species that might be adapted to habitat.