Fig 1.
Andrographis plants grown in hydroponic PFAL system with artificial lighting.
Fig 2.
Experimental design of Andrographis at six planting densities in a PFAL.
Plant cultivation on a floating foam (60×90 cm) includes the following densities: 15, 20, 25, 30, 35 and 40 plants m-2.
Table 1.
Vegetation indices used for Andrographis leaf characteristic assessment.
Fig 3.
Responses of gas exchange parameters: net photosynthesis rate (Pn) (A), stomatal conductance (gs) (B), internal CO2 concentration (Ci) (C) and transpiration rate (E) (D) of Andrographis leaves at six planting densities during vegetative (30 DAT), initial flowering (60 DAT) and flowering (90 DAT) stages. Values are represented as mean ± SE (n = 4). Different letters indicate significant differences between planting densities at p < 0.05. “ns” indicates no significant difference.
Fig 4.
Effects of planting densities on plant growth.
Plant height (A), plant width (B), number of stalks (C) and number of leaves (D) of Andrographis during vegetative (30 DAT), initial flowering (60 DAT) and flowering (90 DAT) stages. Values are represented as mean ± SE (n = 4). Different letters indicate significant difference between planting densities at p < 0.05. “ns” indicates no significant difference.
Fig 5.
Effects of planting density on fresh weight (A) and dry weight (B) in g per one m2 of Andrographis during vegetative (30 DAT), initial flowering (60 DAT) and flowering (90 DAT) stages. The phenotypes of Andrographis grown at different planting densities at 60 (C) and 90 DAT (D). Values are represented as mean ± SE (n = 4). Different letters indicate significant difference between planting densities at p < 0.05. “ns” indicates no significant difference.
Fig 6.
Andrographolide (AP1) content (mg DW-1 m-2) of Andrographis leaves at 6 planting densities during vegetative (30 DAT), initial flowering (60 DAT) and flowering (90 DAT) stages.
Values are represented as mean ± SE (n = 4). Different letters indicate significant difference between planting densities at p < 0.05. “ns” indicates no significant difference.
Fig 7.
The relationship between 17 vegetation indices, eight physiological parameters and two types of AP1 measured among different density treatments during three developmental stages.
Biplot of the PCA model of all samples (A). Heat mapping and clustering analysis of all measured variables using Z-scores for the normalized value (B). Color represents values of each parameter, with dark blue for low values and dark red indicating high values.