Effect of Two Murashige and Skoog (MS)-Based Culture Media Supplemented with mTR or Thiamine and 2iP on In vitro Axillary Shoot Proliferation of Yam (Dioscorea spp.)

Aims: In Côte d’Ivoire, yam production is compromised by susceptibility to pathogens and by the use of tubers as propagation material, leading to lower yields, a risk of genetic erosion and increased disease spread. In the context of food security challenges, the development of micropropagation techniques enabling the production of healthy in vitro seedlings may provide an approach to improving the availability of high-quality plant material. This study aimed to optimise the in vitro culture conditions for yams in order to contribute to the production of healthy in vitro seedlings. Study Design: Explants taken from young potted plants of the Criolo Blanco yam clone grown in the laboratory were used to compare two culture media: medium M1 or MS 3B, consisting of the Murashige and Skoog (MS) basal medium enriched with vitamins and meta-topolin riboside (mTR), and medium M2 or MS/2, enriched with thiamine and 2-isopentenyladenine (2iP). Explant responses were assessed using the number of leaves and shoots, as well as the survival rates associated with each culture medium. Results: A 50 per cent regrowth probability was reached after 16 days in medium M1 and after 9 days in medium M2. Medium M2 had a median of three leaves per plant. Analysis of the results reveals that at T5, 72 per cent of the explants in medium M1 produced leaves and 54 per cent produced shoots, whilst in medium M2, 25 per cent formed leaves and 25 per cent formed shoots; the comparisons were not statistically significant. Conclusion: The findings suggest that the composition of MS-based media may influence explant recovery and vegetative development, although further testing of growth-regulator concentrations is required.