Published online by Cambridge University Press: 08 September 2008
Adapting in vitro transgenic carrots to soil is the most crucial step preceding the field investigation of transgenic carrots. A low proportion of plants, around 0·20, acclimatize to soil (Hardegger & Sturm 1998) and thus prohibit the generation of high-expression carrot lines. In the present paper, a protocol for an efficient soil transfer is presented and the impact of carrot cultivar, soil substrate, tissue culture, and transformation process on transfer process is analysed. Somatic embryo germinants of Daucus carota cv. Rote Riesen 2 and Lobbericher Gelbe Futtermoehre showed a tremendous survival proportion – up to 1·00 – when transferred to their optimal soil substrate: sandy and loamy soil, with low content of macro and micro elements and a pH of 5·8. By optimizing the conditions described here, the proportion of soil acclimatized transgenic carrot plants of D. carota Lobbericher Gelbe Futtermoehre was increased from 0·1 to 0·87, and for the cultivar Rote Riesen from 0·09 to 0·67.