entity Chlorophyll measurement: Absorbance was measured with a spectrophotometer (DU-70 Spectrophotometer, Beckman, USA) at 663.2 and 646.8 nm in a quartz cuvette. A646.8 is the absorbance at 646.8 nm and A663.2 is the absorbance at 663.2 nm, v is volume (ml), DW is dry weight. Chlorophyll protocol attribute method_of variable_of scale_of acronym