Biotic Elicitor-Driven Enhancement of In Vitro Micropropagation and Organogenesis in Solanum tuberosum L. cv. Fianna

This study evaluates the impact of biotic elicitors and hormone regimes on the in vitro establishment, shoot multiplication, and organogenesis of <i>Solanum tuberosum</i> 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 naphthaleneacetic acid (NAA) and 0.5-1.0 mg L^-1 benzylaminopurine (BAP), producing the greatest number and length of shoots and roots. Direct organogenesis was stimulated by bio-elicitors Activane^®, Micobiol^®, and Stemicol^® in (MS) basal medium at mid-level concentrations (0.5 g or mL L^-1), improving shoot number, elongation, and root development. Activane^®, Micobiol^®, and Stemicol^® are commercial elicitors that stimulate plant defense pathways and morphogenesis through salicylic acid, microbial, and jasmonic acid signaling mechanisms, respectively. Indirect organogenesis showed significantly higher callus proliferation in Stemicol^® and Micobiol^® treatments compared to the control medium, resulting in the highest fresh weight, diameter, and friability of callus. 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.