Figure 1.

Main stages of stress-induced microspore embryogenesis in Hordeum vulgare, barley (A–C) and Brassica napus, rapeseed (D–F). A, D: Vacuolated microspores at the beginning of culture. B, E: Proembryos formed after stress treatment to induce embryogenesis, after around 4 days in culture. C, F: Cultures of 30 days showing microspore-derived embryos. C: Barley developing and coleoptilar embryos. F: Rapeseed cotyledonary embryos. A, B, D, E: Toluidine blue-stained semithin sections of Technovit resin-embedded samples, observed under bright field microscopy. C, F: Developed microspore-derived embryos, observed under stereomicroscope. Bars in A, D: 10 μm, in B, E: 20 μm, in C: 0.5 mm, in F: 1 mm.