Effects of ascorbic acid and embryogenic microspore selection on embryogenesis in white cabbage (Brassica oleracea L. var. capitata)

SUMMARYMicrospore embryogenesis in plants is a process by which microspores can switch their developmental pathway from gametophytic to embryogenic via specific inductive stress treatments, which results in the formation of haploid embryos. However, only a small portion of the cultured cells can undergo the entire process to produce embryos, and most die at different developmental stages during culture. The objective of this study was to improve the induction of embryogenesis in an isolated microspore culture (IMC) of white cabbage (Brassica oleracea L. var. capitata) by focussing on the regulation of dead microspores. The results indicated that microspores died rapidly after 24 h at a heat shock temperature of 32.5°C, and that 80–90% were dead after 3 d in culture. Cell purification performed after 3 d in culture, eliminated most of the dead microspores and had a beneficial effect on embryo yield. Similarly, ascorbic acid (AsA) had a positive effect on the number of embryos produced by decreasing the mor...