Tetraploidization Altered Phenotypic Traits and Metabolite Profile of Java Ginseng (Talinum paniculatum (Jacq.) Gaertn.)

Polyploidization is a beneficial technique to enhance the biomass and secondary metabolites concentrations in plants. Java ginseng (Talinum paniculatum (Jacq.) Gaertn.) can be used as an alternative source of nutrition and has both ornamental and medicinal value. To improve the biomass and content of medicinal ingredients, this study established a speedy propagation system to induce polyploid of java ginseng, and tetraploids were successfully produced by exposing axillary buds to colchicine. The most favorable medium for inducing polyploidy was Murashige and Skoog medium devoid of hormonal substances, while immersing stem segments in a solution of 1-3mg/ml colchicine with 48 hours can achieve high rate of tetraploid induction with the maximum rate of 18.03%. Tetraploids were identified from diploids by flow cytometry, and the tetraploids exhibiting darker and thicker leaves, bigger fruit and pollen, larger stomata but less stomatal density, while the aboveground biomass yield reduced significantly, compared with diploids. Tetraploidization also altered the metabolite profile, with 22 metabolites concentrations significantly increased (P<0.05) and 74 metabolites concentrations significantly decreased (P<0.05) in the leaves of tetraploids. Autotetraploid produced in this study could provide novel insights for artificial polyploid breeding and can be utilized as a new germplasm to generate new polyploids.