Production of somatic embryo and transgenic plants derived from breeding lines of Rosa hybrida L.

Abstract

This study was conducted to obtain intron-GUS gene-transferred plants by using somatic embryos (including embryogenic calluses) derived from 2 in vitro root explants of breeding lines (KR056002 and KR056006) bred by crossing between Rosa hybrida ‘Tineke’ and ‘Mirinae Gold’. Calluses were induced from their root explants cultured in Schenk and Hildebrandt (SH) medium, which was supplemented with 5 or 11 mg·L⁻¹ of 2,4-dichlorophenoxyacetic acid (2,4-D). Somatic embryos were generated from the calluses, which were cultured in SH medium supplemented with 3 mg·L⁻¹ of 2,4-D. The ratio of callus formation from in vitro root explants was dependent on the concentration of 2,4-D supplement in the SH medium. Somatic embryos were generated from both KR056002 and KR056006, and embryogenesis was observed from calluses around the somatic embryo. The regenerative capacity of the embryo was maintained longer in calluses derived from in vitro root explants cultured on SH medium supplemented with 11 mg·L⁻¹ of 2,4-D than with 5 mg·L⁻¹ of 2,4-D. Six pseudo-intron-GUS transgenic lines were obtained. The expression rate of the intron-GUS gene in multi-shoots was 100%. After the formation of healthy roots, 3 transgenic lines were transferred to the greenhouse. All 3 lines were reconfirmed as intron-GUS gene transgenic plants by PCR and Southern analyses.