In vitro regeneration of cashew [Anacardium occidentale L. (Anacardiaceae)] trees from grafted plants

Propagation by seeds of the cashew tree (Anacardium occidentale L.) does not allow a faithful reproduction of the mother plant. The objective of this work is to establish an in vitro cashew tree regeneration protocol from the apex of grafted plants. To this end, apex explants taken from plants grafted in greenhouses were disinfected using sodium hypochlorite with 1.2 and 2.4% active chlorine and calcium hypochlorite 2.5 and 5% for 1; 2 ; 3 and 5 min, then cultured on MS medium supplemented with benzylaminopurine (BAP), kinetin and thidiazuron (TDZ) at various concentrations. The main results showed that disinfection of the explants with sodium hypochlorite at active chlorine 1.2 % for 2 min resulted in a low contamination rate (33%). The budding rate and the mean number of buds (1 to 2 buds per explant) did not vary while the best shoot growth (0.4 cm) were obtained on the medium without growth regulators. At the end of these experiments, the protocol for in vitro regeneration from the apex of the cashew tree was established.