Transmission electron micrographs of microspores from the control plants and <i>bcmf26a/b</i> lines.

<p>Pollen at the (A and F) uninucleate microscope stage, (B and G) binucleate stage, and (C and H) mature pollen stage of the control plants and <i>bcmf26a/b</i> plants were observed. (A–C) The control pollen grains showed normal morphology with three germinal furrows and a normal development process of the pollen wall; the pollen intine (D) outside and (E) inside the germinal furrow region developed normally. (F–O) The pollen grains from the <i>bcmf26a/b</i> lines showed two kinds of deficient phenotype. One ultimately produced (F–H) vacuolated pollen grains with disordered formation of the intine. The pollen intine (I) disappeared in some regions, while the intine was (J) abnormally thick in other regions. The other kind of deficient phenotype was the formation of (K–M) swollen pollen grains. The development of pollen cytoplasmic inclusions was abnormal. Remarkable thickening (N) outside and (O) inside the germinal furrow regions was observed, compared with the control pollen. Ba, baculum; Ex, exine; Gf, germinal furrow; In, intine; N, nucleus; SC, sperm cell; Te, tectum.