Optimising Disease-free Sweet Potato [Ipomoea batatas (L.) Lam.] Planting Material via in vitro Culture : Insights from Togo

Abstract

Background and Aims : Sweet potato [Ipomoea batatas (L.) Lam.] is an important food crop that provides food security, income and valuable nutrients. In Togo, its production is limited by the low quality of planting material and the spread of diseases and pests. The use of informal seed systems reduces yields and hinders the development of the sector. Modern biotechnological approaches, in particular in vitro cultivation, allow obtaining healthy and uniform planting material. At the same time, the effectiveness of these methods depends on the genotype, which requires local research. Therefore, studying the response of new sweet potato varieties in vitro is important for increasing productivity and sustainable development of production in Togo. This study assessed the regeneration capacity of five local varieties, with the aim of identifying genotypes best adapted to in vitro conditions. Study Design : The experiment was conducted using a completely randomised design with three replications. Place and Duration of study : The study was carried out at the tissue culture laboratory of the Togolese Agricultural Research Institute (ITRA) during a four- week period from August to September 2025. Methodology : Five (5) newly released varieties were assessed for their micropropagation performance using Murashige and Skoog (MS) medium supplemented with 4.4 g/L MS salts, 5 g/L 6-Benzylaminopurine (BAP), 8 g/L agar, and 24 g/L sucrose. Parameters recorded included bud break rate, shoot number, leaf number, root number, and plantlet height. Data were subjected to analysis of variance (ANOVA), and mean separation was performed using Tukey’s HSD test. Results : The study found significant varietal differences for the number of shoots (p < 0.001), number of leaves (p < 0.05), and plantlet height (p < 0.001); confirming the decisive role of genotype in the formation of morphogenetic reactions. Irène exhibited the highest shoot regeneration potential (9.37 ± 3.6), highlighting its suitability for in vitro multiplication. Gnigbé 2 produced more leaves (0.70 ± 1.2) and attained greater plantlet height (1.26 ± 0.32), indicating enhanced vigour under the tested conditions. While the medium effectively induced callus formation and shoot development, rooting remained suboptimal. Conclusion : These findings underscore the decisive role of genotype in regeneration success and provide a framework for optimising micropropagation protocols of sweet potato in Togo. Further refinement of hormone concentrations and medium composition is recommended to improve rooting efficiency and ensure robust plantlet establishment.