Argan is a horticultural forest species endemic to Morocco, well adapted to arid and semi-arid Mediterranean climates and with high social, ecological, economic and agronomic value. However, argan populations are threatened by overgrazing, lack of natural regeneration and overexploitation as argan oil demand is increasing. As conventional propagation is very problematic, the development of micropropagation methods is imperative. Here, an efficient procedure for micropropagation of argan juvenile material based on axillary budding, is described. Forced shoots obtained from potted plants of two different 2-year-old specimens (AG1 and AG3) were employed as initial explants to establish in vitro shoot proliferation cultures. Explants were established in Murashige and Skoog medium (MS) supplemented with 1 mg L−1 benzyladenine. For shoot proliferation, the best results were obtained when shoots were cultured in MS medium supplemented with 2 mg L−1 meta-topolin, 1 mg L−1 indole-3-acetic acid, 0.65 % agar from Sigma and 3 % sucrose during 6 weeks at 28ºC. Optimal rooting rates were achieved through continuous culture of shoots on medium supplemented with 7 mg L⁻¹ indole-3-butyric acid, with AG3 showing the best results (58 %). Rooted plants were successfully acclimatized using Jiffy pellets and the survival rate after 12 weeks was higher than 50 % in both genotypes. This protocol facilitates the short-term conservation of argan germplasm, ensuring its preservation for future research and restoration efforts.
Piñeiro et al. (Fri,) studied this question.