Role of Sucrose in Microspore Embryo Production in Brassica napus ssp. oleifera

Dun well, J. M. and Thurling, N. 1985. Role of sucrose in microspore embryo production in Brassica napus ssp. oleifera.—J. exp. Bot. 36: 1478–1491. One cultivar of winter oil seed rape (Brassica napus ssp. oleifera) and three cultivars of spring rape were used in a study of the effects of sucrose on microspore survival and embryo induction in cultured anthers. A preliminary study on the winter cultivar (Fiona) revealed that the osmotic pressure of the supernatant of anther homogenates was equivalent to a solution of 17% sucrose. A study of microspore survival and embryo induction in this cultivar on media containing either 8 %, 12%, 16% or 20% sucrose revealed the highest survival (after 16 d) and the greatest number of anthers with induced embryos (after 42 d) occurred on the highest sucrose concentration. A subsequent study on three spring cultivars (Willi, Duplo and Tower) examined microspore survival at 8 d and embryo induction (42 d) on media containing either 8 % or 16 % sucrose and again revealed much higher survival and induction at the higher concentration. The variation in response between the cultivars was also reduced by culture at the higher sucrose concentration. The beneficial effect of the 16% level occurred regardless of the growth environment of the donor plants and of the stage of pollen development at the start of culture. However, macroscopic embryos emerged only from anthers on the 8 % sucrose concentration, suggesting that transfer of anthers from a high to a normal sucrose concentration during culture would ensure that full advantage was taken of the much higher initial survival on the higher concentration