In vitro Plant Regeneration from the Mature Tissue of Navel Orange (Citrus sinensis L. Osbeck) by Direct Organogenesis

An efficient in vitro regeneration system by direct organogenesis from mature nodal and internodal stem segments ofNewhall navel orange (Citrus sinensis L. Osbeck) was developed. Illuminating conditions together with plant growthregulators affected the adventitious bud regeneration frequency and efficiency. The initial 15 d darkness inoculation isbeneficial for the adventitious bud regeneration. The highest regeneration frequency (85.2%) and bud formationefficiency (3.7 per responsive internodal stem segment) were obtained in the media supplemented with 1.0 mg L-1 BAPand 0.5 mg L-1 NAA. ABA at 0.2 mg L-1 positively affected the bud formation efficiency, which amounted to 8.5 buds perinternodal segment in the presence of BAP at 1.0 mg L-1. The adventitious shoots successfully rooted and weretransferred to the soil.