Integrated use of electromagnetic micro-projectile and Agrobacterium: Increase the efficiency of gene transfer to melon

Electromagnetic micro projectile machine was combinedly applied with Agrobacterium LBA4404 strain containing pBI121vector to increase gene transfer to melon (Cucumis melo cv.khatoni). A factorial experiment based on a Completely Randomized Design including the magnetic field (with three levels comprising 400, 700 and 1000 ?T (microtesla)), distance from accelerating chamber (one and zero (no spaces) centimeter) and inoculation time (30 and 60 seconds) was carried out. Results showed that, groups treated with a 700 ?T, distance of one centimeter and 30 and 60 second inoculation (respectively, 26.66% and 22.2% regenerated transform plant) had the best transformation rate; decreasing the distance to zero in 700 ?T treatment decreased the rate of transformation (15.5, 11.1 in 30 and 60 second inoculations respectively); While transformation efficiency for zero distance in 400 ?T treatment (20, 11.1 in 30 and 60 second inoculations, respectively) were more effective than one cm distance (6.6, 8.8 in 30 and 60 second inoculation, respectively). In 1000 ?T treatments only with a distance of zero and inoculation time of 30 seconds, 2.2 % of transformed plant were regenerated which represents the destruction effect of this electromagnetic field on plant stricture. Histochemical GUS assay confirmed the presence and expression of transcript in regenerated plant. 10.37% Average regeneration of transgenic plants in all treatments compared with control treatment (transformation without using of electromagnetic micro projectile machine) with a regeneration rate of 2.22 % indicates the effective operation of the electromagnetic micro projectile machine.