The tetrasporophyte wrapped by callose is of simultaneous type.

四体呈四面体型，被胼胝质壁所包围。

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

营养细胞的细胞质中继续积胼胝质，花粉成熟对胼胝质在小孢子形成和发育过程中的功能讨论。

Abbreviation: T: Tapetal; N: Nucleus; TE：Tetrad; TW: Wall of tapetal cell; V: V acuole; D: Dictyosome; C: Callose; M: Mitochondria.

绒毡层细胞，N：细胞核，TE:四体，TW：绒毡层细胞壁，V：液胞,D：高尔基体，C：胼胝质壁，M：线粒体。