Figure 3.

Cell wall staining in Ginkgo biloba and Gnetum gnemon. A, Ginkgo pollen grain showing aniline blue staining of internal male gametophyte walls and intine (arrows; one day of in vitro growth). B, Aniline blue stain localized to inner wall of Gnetum pollen (arrow) before exine shedding (one day of in vitro growth). C, D, Gnetum pollen grain after exine shedding (eight days of in vitro growth). C, Lack of aniline blue staining of intine (compare with DIC view in D). Note pollen is larger than first-day pollen in B and now contains abundant starch grains. Scale bars, 10 μm.