FIGURE 5.

Developmental pathways observed in C. sativa (industrial hemp) microspore culture. (A–C) Male gametophyte development in C. sativa during in vitro culture. (A) Uninucleate microspores; (B) uninucleate microspores after 3 days in culture media; (C) symmetrically divided microspore with two equally sized nuclei; (D) multinucleate structure without organization and still enclosed in exine; (E) globular multicellular structure with developing exine; and (F) heart-shape embryo with two distinct domains. The nuclei in (A–C) are stained with the nuclear dye 4′,6-diamidino-2-phenylindole (DAPI) to indicate viability.