In vitro propagation of sweet cucumber (Solanum muricatum Ait): Effects of auxins and cytokinins

Sweet cucumber (Solanum muricatum Ait.) is a perennial shrub native to the Andean region and closely related to tomato and potato. Its fruit is valued for its high-water content and nutritional properties, including antioxidants, potassium, and vitamin C. However, its agricultural potential is constrained by low germination rates, high heterozygosity, and susceptibility to diseases. In vitro culture techniques offer a viable alternative for obtaining plant material with high genetic and phytosanitary quality. This study evaluated the in vitro regeneration of S. muricatum through organogenesis and shoot proliferation. During the establishment phase on semi-solid MS medium, supplementation with 1.5 mg L-1 indole-3-acetic acid (IAA) enhanced bud regeneration, increased shoot height (2.69 cm), and promoted root formation, whereas higher concentrations (2.0 mg L-1) negatively affected regeneration. Shoot proliferation was stimulated by specific combinations of auxins and cytokinins, particularly IAA+BAP (1.0 + 0.2 mg L-1), which produced taller explants (7.7 cm) with a greater number of leaves (11.9). These findings provide useful information for optimizing in vitro propagation conditions for S. muricatum, with potential applications in germplasm conservation, production of disease-free plants, and genetic improvement of this underutilized species.