High-frequency embryogenesis in male sterile plants of Brassica napus through microspore culture

Abstract

Microspores from several Polima cytoplasmic male sterile (Pol-CMS) and Diplotaxis muralis male sterile (Mur-MS) oilseed rape lines were cultured in a modified Nitsch and Nitsch medium in the dark for 4 weeks. High androgenic frequencies were observed in microspore cultures initiated from plants of both male sterile (MS) types. In cultures maintained at a constant temperature (30 °C) 1 or 2% of the microspores from Pol-CMS or Mur-MS lines, respectively, developed into embryos. A greater percentage of the embryos obtained from the Pol-CMS lines were of good quality than those obtained from the Mur-MS lines (25 vs. 5%). Twenty percent of the plants regenerated from embryos of both lines were spontaneous doubled haploids. The results suggest that no unfavorable cytoplasmic–nuclear genome interaction affecting androgenic potential exists in plants exhibiting Polima or Diplotaxis muralis male sterility.