Comparison of selected commercial sugarcane varieties for use in a stable transformation programme

Ten commercial sugarcane varieties, N12, N14, N19, N24, N25, N26, N27, 75E2 47, 84E1334 and NCo376 were tested for suitability for transformation in te rms of their embryogenic callus production and transient expression levels. Based on an increase in callus mass over time, varieties N12, N19, N27, NC o376 and 84E1334 outperformed other varieties on Murashige and Skoog medium containing 2,4-dichlorophenoxyacetic acid (3 mg/L). Using microprojectile bombardment and a plasmid which carries the maize anthocyanin gene, transie nt expression levels of varieties were determined by counting the number of red foci per cm(2) callus material 48 hours after delivery. Varieties NCo3 76, N12, N27 and N19 showed high transient expression levels of between 1 0 00 and 1 450 red foci per cm2 callus material. Regeneration regimes for var ieties differed and these are discussed. Three varieties, NCo376, N12 and N 19, were selected for further stable transformation studies on the basis of promising performance.