Asian Journal of Agriculture and Allied Sciences

This study evaluated the genetic transformation of purslane (Portulaca oleracea L.) through direct injection of Ri plasmids isolated from Agrobacterium rhizogenes ATCC 15834. Ri plasmid DNA was obtained from bacterial cultures incubated for 24, 48 and 72 hours, yielding concentrations of 14.49, 27.75 and 19.59 ng µl-1, respectively, with a purity ratio of 1.8. Fifteen-day-old purslane seedling stems were inoculated with the three plasmid concentrations, while controls received sterile distilled water. Transformation was assessed by the formation of tissue masses and hairy roots at injection sites, followed by establishment of hairy root cultures on solid MS medium. Among the tested treatments, 27.75 ng µl-1 was most effective, producing 92% hairy root formation after 10 days, with 3.2 hairy roots per responsive stem and 285 tissue masses. The 14.49 and 19.59 ng µl-1 treatments produced lower responses, with hairy root formation of 40% and 64%, respectively, while the control showed no tissue masses or hairy roots. Hairy roots induced by 27.75 ng µl-1 were successfully excised and maintained as dense, branched cultures after subculturing at 20-day intervals. Molecular confirmation was performed using genomic DNA extracted from transformed tissue masses, hairy roots and non-transformed control roots. Polymerase chain reaction analysis with rolA-specific primers produced a 248 bp band in transformed tissue masses and hairy roots, whereas no corresponding band was detected in the control. These findings confirm the genetic transformation of purslane using isolated Ri plasmids.