Figure 7.

Viability and germination frequency of nip7;1 pollen. Pollen harvested from flowers of the wild type (WT) and nip7;1 T-DNA mutant lines were tested for viability and germination in vitro as described in “Materials and Methods.” A, The percentage of geminated pollen was calculated after 16 h of incubation of pollen in pollen growth medium. Error bars show sd (n = 5, with 60–200 pollen grains per replicate). Significant differences (***, P < 0.001 and ****, P < 0.0001) based on two-way ANOVA are indicated. B, Pollen viability was tested by staining mature pollen from plants grown hydroponically in low-boric acid medium with cell-permeable fluorescein diacetate. The hydrolysis of fluorescein diacetate within viable pollen grains produces a green fluorescent signal detected with a fluorescein isothiocyanate filter set. Arrows show characteristic defective pollen grains detected in nip7;1 pollen. Bars = 50 μm.