Abstract:

The transformation of Helianthus annuus L. mediated by Agrobacterium rhizogenes was reported. Almost all roots induced by different Agrobacterium rhizogenes bacterial strains which could survive in the selection medium (1/2 MS) containing 200 mg/L kanamycin were putative hairy roots. The effects of bacterial strains, bacterial concentrations, acetosyingone, silver nitrate and co-cultivation pH on sunflower transformation were investigated. For sunflower transformation, the optimal conditions were strain R1205, 1.0 bacterial concentration (OD₆₀₀), 15 minutes- infection, co-cultivation for 3 days as well as 30 μmol/L acetosyingone (without silver nitrate) and pH 6.5. Under this condition, the hairy root production frequency was 23.7% (cotyledon) or 81.6% (hypocotyl).

Key words: Sunflower, Agrobacterium rhizogenes, Hairy root, Optimal treatment condition