In vitro regeneration of cashew (Anacardium occidentale L.) using apical meristem culture

Cashew (Anacardium occidentale L. 1753) orchards in Côte d'Ivoire are made up of unselected trees with very low yields. As a result, farmers are increasingly expanding their production areas, thereby reducing the amount of land available for cultivation. To optimize seedling production, meristem-tip from mature cashew trees were grown under in vitro conditions. Sodium hypochlorite (NaClO) was used alone or in combination with 0.1% mercury chloride for explants sterilisation. Meristems tips were then incubated on three basal media, Woody Plant Medium (WPM); Murashige and Skoog medium with vitamin Gamborg (MS) and Gamborg medium (B5), supplemented with different concentrations and combinations of 6-benzylaminopurine (BAP) and α-naphthaleneacetic acid (NAA) for shoots induction. For roots inductions, NAA and Indole-3-butyric acid (IBA) were applied. The lowest percentage of contamination (28%) was obtained with NaClO combined with mercury chloride. Basal medium WPM causes less meristem necrosis. BAP (1 mg L−1) combined with 1 mg L−1 NAA resulted in the development of 91.66% meristems into leafy shoots after 10 weeks of incubation. Meristem tip culture can constitute an alternative for cashew plants regeneration, and an important step for cashew tree improvement in Côte d'Ivoire.