Figure 2

Pollen germination, pollen tube elongation and papilla cells in H3 (A, B and C) and S1 (D, E and F). Pollen grains germinate on stigma of H3 (A) and S1 (D) at 6 h after hand-pollinations, the pollen tubes are screwy (arrows in D) and fail to penetrate into papilla cells in S1. At 72 h after self-pollination, the pollen tubes have passed into the micropyle (arrow in B) of ovule of H3 (B), but no pollen tubes are found in S1 ovary (E). Papilla cells of S1 (F) are much shorter than that of H3 (C). A-B, D-E, Fluorescence micrographs. C and F, Scanning electron micrographs. Bar = 100 μm.