IMPROVEMENT OF PROTOPLAST CULTURE PROTOCOLS FOR BETA-VULGARIS L (SUGAR-BEET)

The effects of NaCl, feeder cells and the embedding of protoplasts in calcium alginate have been investigated in an attempt to improve cultu re conditions of recalcitrant sugar beet (Beta vulgaris L.) mesophyll protoplasts. While the use of NaCl in all instances proved detrimental to protoplast development, the other two treatments had clear benefic ial effects. Minimum plating densities, necessary to sustain cell divi sion, could be reduced to < 5 % (< 4000 protoplasts / ml) of the contr ol levels and plating efficiencies could be significantly enhanced hy approx. 10 fold. Plants could still be regenerated from soft calli der ived from mesophyll protoplasts cultured under the modified conditions at a frequency of 20 - 30 %. In particular, the use of alginate is co nsidered of potentially great importance for the further application o f beet protoplasts for other aims e.g. asymmetric hybridization.