Biotic Elicitor-Driven Enhancement of in Vitro Micropropagation and Organogenesis in <em>Solanum tuberosum</em> L. cv. Fianna

This study evaluates the impact of biotic elicitors and hormone regimes on the in vitro establishment, shoot multiplication, and organogenesis of Solanum tuberosum L. cv. Fianna under controlled laboratory conditions. Explants derived from pre-treated tubers were cultured on Murashige and Skoog (MS) medium supplemented with vitamins and varying concentrations of growth regulators or elicitors. Aseptic establishment achieved a high success rate (~95%) using a 6% sodium hypochlorite disinfection protocol. Multiplication was significantly enhanced with a combination of 0.2 mg L⁻¹ ANA and 0.5–1.0 mg L⁻¹ BAP, producing the greatest number and length of shoots and roots. Direct organogenesis was stimulated by Activane®, Micobiol®, and Stemicol® at mid-level concentrations (0.5 g or mL L⁻¹), improving shoot number, elongation, and root development. Indirect organogenesis showed significant callus proliferation, particularly in Stemicol® and Micobiol® treatments, which yielded the highest fresh weight, diameter, and friability of callus. Statistical analysis using ANOVA and Tukey’s test (p ≤ 0.05) validated these findings. The results demonstrate the potential of biotic elicitors as alternatives or enhancers to traditional plant growth regulators in potato tissue culture, supporting more efficient and cost-effective micropropagation strategies.