Using Peat Pellets in Liquid Media to Root Sunflower Tissue Culture Plants

Traditional plant breeding is often limited by the genetic diversity within a species. The use of biotechnology allows introducing into a plant, specific traits that come from the same or another plant species. In this paper, we focus on tissue culture of sunflower (Helianthus annuus L., Asteraceae), particularly related to rooting transgenic sunflower plantlets. Sunflower is notoriously recalcitrant to genetic transformation and regeneration when subjected to tissue culture. Prior to 1985 there had only been four reports, as noted by Paterson and Everett (1985), of successful regeneration of sunflower plants in tissue culture. Although this report is more than 20 years old, sunflower continues to be a challenging species in tissue culture (Baker et al. 1999; Dhaka and Kothari 2002; Hewezi et al. 2002; Radonic et al. 2006) including rooting (Paterson 1984; Gürel and Kazan 1998). The objective of our study was to compare agar and liquid media for rooting transgenic sunflower plantlets.