Optimizing L-DOPA production in velvet bean (Mucuna pruriens) through photoperiod and growth regulator manipulation

Purpose: Due to the short-day nature of the velvet bean, which triggers flowering in the autumn with decreasing day length, its production in temperate and high-latitude regions under greenhouse conditions requires modifications in its flowering and fruiting habits. Therefore, this study aimed to optimize L-DOPA production by investigating photoperiod changes and hormonal regulation to encourage flowering and fruiting under greenhouse conditions. Research Method: Treatments included photoperiod at two levels (۱۳-hour darkness and natural day length) as the first factor and growth regulators at seven levels (۵۰ and ۱۰۰ mg of gibberellin, ۲۰ and ۵۰ mg of paclobutrazol, ۵۰ and ۱۰۰ mg of cytokinin, and a control treatment) as the second factor. Findings: the effects of photoperiod, growth regulators, and their interaction were significant for all traits except for internode length. The natural light treatment resulted in a ۳% delay in flowering compared to the ۱۳-hour dark treatment, whereas the ۱۳-hour dark treatment exhibited higher fruit weight, seed yield, and L-DOPA content (۱۸%) compared to the natural light. Moreover, the application of ۵۰ mg paclobutrazol reduced the days to flowering by ۵۵ days compared to the control. On the other hand, the ۵۰ mg paclobutrazol treatment showed significant increases in fruit weight (۵۹%), seed yield (۶۵%), and L-DOPA content (۳۱%) compared to the control. Research limitations: No limitations were found. Originality/Value: Overall, extending the dark period improved velvet beans' yield and yield components. Furthermore, paclobutrazol enhanced yield more effectively than gibberellin and cytokinin. Based on the experiment, the best treatment for achieving maximum quantitative yield and L-DOPA content was ۱۳-hour darkness combined with ۵۰ mg of paclobutrazol.

کلیدواژه ها:

cytokinin ، gibberellin ، Medicinal plants ، paclobutrazol