Figure 4.

Characterization of the male-sterile phenotype. A to C, Flowers from transgenic lines; note the absence of fruit capsules and fallen flowers. D and E, Untransformed tobacco flowers and fruit capsules. Comparison of stamens and stigma: note shorter stamens in transgenic lines (F) compared to untransformed (G). Comparison of mature anthers: note abundant pollen in untransformed anther (I) and the lack of pollen in transformed anther (H). J, Transgenic fruit capsule with seeds after pollination of transgenic stigma with untransformed pollen. K, Germination and growth of T₁ seedlings on Murashige and Skoog medium with 500 μg/mL spectinomycin. wt, Untransformed; 4A, T₁ transgenic line 4A; 4B, T₁ transgenic line 4B, obtained after pollination with untransformed pollen.