The effect of magnetic field strength on shoot regeneration and Agrobacterium tumefaciens-mediated gene transfer in flax (Linum usitatissimum L.)

This study was conducted to determine the effects of magnetic field (MF) strength on shoot regeneration and Agrobacterium tumefaciens-mediated gene transfer in flax (Linum usitatissimum L.). Seeds of flax cv. Madaras were exposed to different MF strengths (0 - control, 75, 150, and 300 millitesla (mT)) for 24 h by using an electromagnetic generator system fabricated in laboratory conditions. After sterilization, seeds were germinated on MS (Murashige and Skoog) medium in Magenta vessels. Hypocotyl explants excised from 7-days-old seedlings were used for regeneration. GV2260 strain of Agrobacterium tumefaciens was used in transformation studies. Inoculated hypocotyls were cultured on MS medium containing 1 mg/l BAP (6-benzylaminopurine) and 0.02 mg/l NAA (naphthaleneacetic acid) for 2 days by co-cultivation. Then, they were transferred to MS medium containing the same growth regulators, 100 mg/l kanamycin and 500 mg/l Duocid for selection. The presence of the nptII gene was verified by PCR (polymerase chain reaction) analysis in putative transgenic plants. The highest results with respect to shoot regeneration and transformation frequency were obtained from treatments of 75 mT MF strength.