Inhibitory effects of riboflavin (Vitamin B2) on the in vitro rooting and nutrient concentration of explants of peach rootstock GF 677 (Prunus amygdalus × P. persica)

The effect of vitamin riboflavin (B2) on in vitro rooting of the almond × peach hybrid clone GF 667 was studied. Riboflavin was added in five concentrations: 0 (control), 0.5, 1.0, 1.5 and 2.0 mg l−1. After 4 weeks in culture, riboflavin did not stimulate adventitious rooting of the explants and rooting was very low in comparison to the control treatment. A high percentage of shoots on the rooting media containing the two highest concentrations of Vitamin B2 had shown symptoms of chlorosis and apex necrosis.