Articles
Improving phytochemicals and antioxidant activity of clove basil (Ocimum gratissimum L.) with far-red and UV-A light supplementation in late production stages
Article number
1423_35
Pages
277 – 284
Language
English
Abstract
This study aimed to improve the growth and phytochemicals of clove basil (Ocimum gratissimum L.) under controlled environment system.
Supplemental far-red (FR, 710-740 nm) and UV-A (360-370 nm) were provided 42-49 days after sowing during the late growth stages, in addition to a 200 µmol m‑2 s‑1 from 80% white LEDs and 20% red LEDs (660 nm) with 16-h photoperiod LEDs lighting treatment.
Plants grown under supplemental FR produced lower shoot (13.6 g) and root fresh weights (4.53 g), increased plant height (25.55 cm) and branch number (12.8), while slightly lower leaf number (11.1). Comparing to supplementing with UV-A light led to greater shoot fresh weight (32.53 g), height (38.4 cm), and leaf number (18.4), however, it led it lower branch number (11.4). Secondary metabolites were measured in leaves and root and expressed in terms of total phenolic content (TPC), total flavonoid content (TF) and total anthocyanins (ACN), along with the antioxidant activity (AA) by ferric reducing ability power (FRAP), oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.
The results showed that TPC, TF, and AA increased significantly in both leaves and root when FR was applied.
The supplementation of UV-A had similar effects to FR that it increased TPC and ACN in leaves and improved AA when measured by FRAP, however, in lower extent compared with FR supplementation.
The effect of UV-A in the roots was comparable to FR in the way that it increased TPC and TF, thus, giving the highest AA measured by ORAC and DPPH. In conclusion, adding FR or UV-A radiation later in the growth cycle can enhance secondary metabolites production and antioxidant activity in clove basil grown under LEDs.
Supplemental far-red (FR, 710-740 nm) and UV-A (360-370 nm) were provided 42-49 days after sowing during the late growth stages, in addition to a 200 µmol m‑2 s‑1 from 80% white LEDs and 20% red LEDs (660 nm) with 16-h photoperiod LEDs lighting treatment.
Plants grown under supplemental FR produced lower shoot (13.6 g) and root fresh weights (4.53 g), increased plant height (25.55 cm) and branch number (12.8), while slightly lower leaf number (11.1). Comparing to supplementing with UV-A light led to greater shoot fresh weight (32.53 g), height (38.4 cm), and leaf number (18.4), however, it led it lower branch number (11.4). Secondary metabolites were measured in leaves and root and expressed in terms of total phenolic content (TPC), total flavonoid content (TF) and total anthocyanins (ACN), along with the antioxidant activity (AA) by ferric reducing ability power (FRAP), oxygen radical absorbance capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.
The results showed that TPC, TF, and AA increased significantly in both leaves and root when FR was applied.
The supplementation of UV-A had similar effects to FR that it increased TPC and ACN in leaves and improved AA when measured by FRAP, however, in lower extent compared with FR supplementation.
The effect of UV-A in the roots was comparable to FR in the way that it increased TPC and TF, thus, giving the highest AA measured by ORAC and DPPH. In conclusion, adding FR or UV-A radiation later in the growth cycle can enhance secondary metabolites production and antioxidant activity in clove basil grown under LEDs.
Authors
T. Weeplian, P. Somsong, T. Tayjasanant, S. Kiravittaya
Keywords
artificial lighting, clove basil, phytochemicals, antioxidant activity
Online Articles (43)