Figure 2.—

Phenotypic characterization of pgd/+ and tgd/+ mutants. (A–F) Pollen germination defective (PGD) mutants, pgd4 (A–C) and pgd7 (D–F). Mature pgd/+ tetrads stained with FDA (A and D) and DAPI (B and E) and after in vitro pollen germination (C and F) are shown. (G–K) In vitro pollen germination assays for pollen tube growth in wild type (WT) (G) and (TGD) mutants, tgd1 (H), tgd3 (I), tgd7 (J), and tgd10 (K). Solid arrows indicate defective pollen tubes. (L–O) Phenotypic analysis of a tgd19 homozygous line: (L) silique from a self cross showing reduced seed set (all seeds are at the top of the silique); (M–O) representative images of 3 DAP pistils stained with DAB; (M) DAB-stained pistil showing pollen tube growth in the upper third of the pistil, (N) aspect of abnormal and nondirectional pollen tube growth in transmitting tissue, and (O) detail of the upper third of the pistil showing the first ovules targeted by pollen tubes (open arrow indicates undeveloped ovule). Bars: A–F, 25 μm; G–K, 50 μm; N and O, 100 μm; M, 250 μm.