In vitro root induction improvement by culture in darkness for different globe artichoke cultivars

A propagation protocol was developed and optimized for globe artichoke (Cynara scolymus L.) plants of cvs “Blanca de Tudela,” “Calico,” and “Salambo.” For culture initiation and shoot proliferation, the effect of different kinetin (K) concentrations in the culture medium on shoot induction was tested. A study was also conducted to evaluate different in vitro rooting strategies. The results indicate that a low level of kinetin (1.4 μM) was optimal for the three cultivars tested for both shoot induction and multiplication. The best results for root induction (73.3% in “Blanca de Tudela,” 80% in “Calico,” and 93.3% in “Salambo”) were achieved with a 5-d culture in darkness, in the presence of 29.5 μM indolebutyric acid (IBA). The survival percentage of plants rooted was higher after acclimatization, 75–83%. The results presented here show that a low level of kinetin and darkness appear to be key factors in a plant propagation protocol for artichoke.