AGROBACTERIUM-MEDIATED TRANSFORMATION OF ALMOND LEAF PIECES

A protocol for Agrobacterium-mediated transformation of leaf pieces fr om two almond cultivars has been developed. This protocol gave a trans formation percentage of 48.6 for the cultivar MN51 and 27.9 for the cu ltivar 'Supernova'. The Agrobacterium tumefaciens strain LBA 4404 carr ying a binary vector plasmid pBinGUSint has been used. A critical step for optimal transformation was the pre-culture period of leaf pieces prior selection on medium containing kanamycin. Both cultivars showed an almost doubled transformation percentage when the selection was sta rted at day 6 compared to day 0. The presence of neomycin phosphotrans ferase II and beta-glucuronidase genes carried by pBinGUSint was confi rmed in transformed explants both by Southern blotting analysis and en zyme activity assays.