Van Emmenes, L., Vegetable and Ornamental Plant Institute, Agricultural Research Council, Pretoria, South Africa
Veale, A., Vegetable and Ornamental Plant Institute, Agricultural Research Council, Pretoria, South Africa
Cohen, A., Agricultural Research Organisation, Volcani Center, Bet Dagan, Israel
Arazi, T., Agricultural Research Organisation, Volcani Center, Bet Dagan, Israel

Ornithogalum, also known as chincherinchee or star-of-Bethlehem has become popular as a cut flower and pot plant due to the remarkable white, yellow and orange flowers characterized many of the cultivars. Two Ornithogalum species are being cultivated, namely O. thyrsoides and O. dubium which are susceptible to Ornithogalum mosaic virus (OMV). Virus infections are characterised by mottled, mosaic-patterned leaves, stems and deformed flowers. This study investigated the transformation of Ornithogalum for virus resistance by using the Agrobacterium tumefaciens strain AGL1. The gene constructs used contained either the viral coat protein or replicase genes under control of either the ΔSVB or UBQ3 promoters. Leaves from in vitro plants of an O. dubium × O. thyrsoides hybrid (line A2) were used as explants which were wounded to promote infection in the Agrobacterium suspension. Co-cultivation continued for 4 days in the dark, pre-selection was performed on 250 mg/L cefotaxime (in the dark) and selection was performed on 80 mg/L kanamycin and 250 mg/L cefotaxime. Eighteen putative transgenic lines were selected, multiplied in vitro and transferred to a glasshouse for hardening. PCR and real-time RT-PCR were performed and the integration of the transgenes into these plants was confirmed. Thus, this is a novel study reporting the unique transformation procedure of the monocotyledonous flower Ornithogalum using the Agrobacterium tumefaciens strain AGL1.