Effect of explant plant source and acetosyringone concentration on transformation efficiency of wheat cultivars
Gene introduction into crop plants through genetic manipulation is a better alternative to conventional breeding for the improvement of stress tolerance. Agrobacterium-mediated transformation offers precise integration of genes into the genome with enhanced transgene stability. There are a number of factors which influence the rate of genetic transformation. The theme of this study is to exploit the explant source and acetosyringone concentration for the efficient development of Agrobacterium-mediated gene delivery system in wheat cultivars Inqilab 91 and Chakwal 97. Seedlings, mature embryos and calli used as explant sources for transformation in both the cultivars showed positive response. It was further observed that mature embryos produced maximum transformation efficiencies of 40.0 and 36.25% with 37.5 and 31.03% of regeneration frequencies of transgenic plants for Chakwal 97 and Inqilab 91, respectively. Seedlings produced 33.75 and 27.5% while calli produced 26.25 and 22.5% transformation efficiencies for both the cultivars. Acetosyringone concentration is also a limiting factor in transformation experiments especially in the case of cereals crop. Different concentrations of acetosyringone were used at the time of co-cultivation for optimization of the transformation protocol and maximum transformation efficiencies of 52.44 and 47.56% were obtained with 50 μM of acetosyringone from the cultivars Chakwal 97 and Inqilab 91, respectively.
Key words: Wheat, agrobacterium, transformation, explant, acetosyringone.