Abstract

Six nutrient formulations were studied for their efficacy in inducing mitosis in white lupin seedling cotyledon protoplasts of which the formulations of Schäfer-Menuhr & Stürmer (AS) and Kao (K8p) were found to be superior over the other four when supplemented with 6-benzylaminopurine and a-naphthaleneacetic acid (a-NAA). An ultrafiltration treatment of K8p increased mitotic frequency by 130% when compared with the untreated control. Medium enrichment with 0.2% bovine serum albumin (BSA) brought about a dramatic 1341% rise in protoplast division in comparison with BSA-free medium but only when the enrichment was carried out in Kao and Michayluk (KM8p) background containing 2,4-dichlorophenoxyacetic acid, a-NAA and zeatin. A higher number of protocolonies (each proliferating from single protoplast following multiple divisions) were seen in 0.4% BSA. With this breakthrough in white lupin protoplast research, it is now possible to reproducibly obtain protocolonies that was hitherto not possible. © 2008 The Authors.