The exine is composed of tectum, columellae, foot layer and endexine. 花粉外壁由顶盖层、柱状层、底层及外壁内层所组成。
The outer pollen wall ultrastructure of 4 excellent germplasms and their cutting offsprings showed that the tectum,columellac,foot layer and endexine had no notable variation. 花粉外壁超微结构所显示的覆盖层、柱状层、基层和外壁内层的形状或厚度，4份优质资源与其扦插后代均无明显变化。
