Accumulation of phytochemicals at different growth stages of Cleome gynandra grown under greenhouse and microplot conditions ​

Abstract

Phytochemicals are bioactive non-nutrient plant compounds that accumulate in response to environmental changes and possess medicinal properties. The concentration of these useful phytochemicals is well associated with the stage of the crop and also the management practices adopted. Therefore, a greenhouse and open field microplot experiments were conducted to investigate the accumulation of phytochemicals at different growth stages of Cleome gynandra. Seven treatments constituting fifth leaf stage (control), vegetative, flower-bud, flowering, pod initiation, pod filling and physiological maturity stages were arranged in RCBD, with 10 replications. Young leaves and tender shoots were harvested weekly and then subjected to phytochemical analysis. Data on antioxidant activity (AA), total phenolics (TP), total flavonoids (TF) and proanthocyanidins (PAs) were determined prior to analysis of variance through SAS Software. Under greenhouse conditions, relative to the control, accumulation of AA and PAs was the highest (66.84 mg GAE/g and 18.62% DM) at flower-budding stage, whereas the lowest (39.63 mg GAE/g and 2.26% DM) was observed at pod initiation stage, respectively. No significant (P 0.05) effect on TP and TF contents were observed. Under microplot conditions, the highest (58.02 mg GAE/g) AA was observed during flower-budding stage and the lowest ( 30.14 mg GAE/g) was observed at physiological maturity. In contrast, the accumulation of TP and TF was the highest (20.23 mg GAE/g and 8.11 mg QE/g) during flower-budding stage, whereas the lowest (3.18 mg GAE/g and 0.93 mg QE/g) was observed at pod initiation stage. However, no significant (P 0.05) effect was observed on PAs. In conclusion, the phytochemicals evaluated in C. gynandra similarly had the highest accumulation at the flower budding stage under greenhouse and open field microplot conditions, however, they started declining at pod initiation stage towards physiological maturity.