The tetrasporophyte wrapped by callose is of simultaneous type.

四分呈四面，胼壁所包围。

These results indicate that callose metabolism is active and very important not only in microsporogenesis but also in microgametogenesis in rice.

营养细胞的细胞中继续积累胼，花粉成熟对胼小孢子形成和发育过程中的功能进行了讨论。