Characterization of Amino Acid Analogue Resistant Somatic Hybrid Cell Lines of Daucus carota L.

Abstract

Summary Intraspecifices somatic hybrid carrot cell lines were found to differ in a number of characters. Three lines tested had low (31.1h), medium (52.6h) and high (62.5h) doubling times during exponential growth and their growth rates were only slightly reduced in the presence of the amino acid analogues, 5MT and/or AEC. The hybrid lines expressed high levels of resistance to both inhibitors similar to that of the resistant parental line and highly exceeding that of the sensitive parental line. Amino acid analogue resistance was stably maintained for more than 250 cell generations in the absence of the inhibitors. SDS-polyacrylamide gel electrophoresis revealed the presence of a polypeptide of MW 94,000 unique to the 5MT-resistant parental and all somatic hybrid lines. These results further support the somatic hybrid nature of the lines selected after protoplast fusion.