大孢子的发育及胚囊的形成：造孢时期，造孢细胞发育成大孢子母细胞。
Development of megaspore and formation of embryo sac: the ovule has a layer of parietal cells at the sporogenous stage.
大孢子的发育及胚囊的形成：造孢时期，造孢细胞发育成大孢子母细胞。
Development of megaspore and formation of embryo sac: the ovule has a layer of parietal cells at the sporogenous stage.
应用推荐