Comparative Growth and Bacoside Production in Diploid and Tetraploid Bacopa monnieri (L.) Wettst. Cultivated Indoors via Hydroponic and Soil Culture Systems

Abstract

Bacopa monnieri, a cognitive-enhancing herb crucial in health supplements, faces quality variations and contamination by toxic substances in conventional field cultivation, which hinders industrial use. Here, indoor cultivation of diploid (2x) and tetraploid (4x) B. monnieri using hydroponic and soil systems was studied. Soil cultivation promoted longer shoot lengths but resulted in lower biomass and chlorophyll contents compared to hydroponic cultivation. Conversely, soil cultivation significantly elevated total phenolics, total triterpenoids, bacoside A3, and bacopaside X contents in both lines, showing 1.7- to 3.3-fold increases over hydroponic cultivation. Furthermore, 4x plants grown in soil had higher bacopaside II and total bacoside contents than hydroponically grown plants, with 2- and 1.5-fold increases, respectively. Yet, no significant differences were observed in growth and pigment between 2x and 4x lines under the same system. Similarly, no significant differences in bioactive compound productions were found between 2x and 4x hydroponically grown plants. However, in soil, 4x plants exhibited higher total phenolic content, bacopaside II, and total bacoside contents compared to 2x plants. Interestingly, 2x plants grown in soil were the top performers for bacoside production per plant. These findings optimize cultivation practices to meet industry demands, warranting further research into large-scale production techniques.