Indirect Adventitious Shoot Organogenesis and Plant Regeneration from Solanum nigrum L

Solanum nigrum L. plays an important role in anti-tumor activity. Previous studies have reported an imperfect in vitro regeneration system with unclear regeneration processes. This study firstly screened the optimal explant type for regeneration, and leaf explants were finally selected as the experimental materials. On this basis, the effects of plant growth regulator combinations and sucrose concentrations on adventitious shoot induction, shoot elongation and rooting were systematically investigated using leaf explants. The results showed that leaf explants exhibited the highest adventitious shoot induction capacity, with an induction rate of 100.00%, significantly higher than petioles (71.33%) and stem segments (51.67%). Using leaf explants, the optimal Murashige and Skoog (MS) medium for adventitious shoot induction contained 2.0 mg·L^-1 6-benzyladenine (BA), 0.1 mg·L^-1 α-naphthaleneacetic acid (NAA), 30 g·L^-1 sucrose and 0.7% (w/v) agar, achieving a stable adventitious shoot induction rate of 100.00%. The optimal medium for adventitious shoot elongation was MS supplemented with 0.5 mg·L^-1 6-BA, 0.1 mg·L^-1 NAA, 30 g·L^-1 sucrose and 0.7% (w/v) agar, with an average of 27.67 elongated adventitious shoots per explant. The optimal rooting medium was half-strength MS medium containing 0.1 mg·L^-1 NAA, 30 g·L^-1 sucrose and 0.7% (w/v) agar, with a rooting rate of 96.67%. This study successfully established a complete and efficient tissue culture system for S. nigrum, which will facilitate large-scale propagation of this medicinally valuable plant.