Spectrophotometric determination of chlorophylls in different solvents related to the leaf traits of the main tree species in Northeast China

Abstract

The accurate detection of the leaf chlorophyll (Chl) is of substantial importance for the immediate assessment of forest conditions to manage and conserve forest ecosystems. We compared 80% acetone, 95% ethanol, and dimethyl sulfoxide (DMSO) over a range of incubation times (2, 4, 6, 8, 18, 26, and 32 h) to determine the Chl contents of 12 tree species in northeast China. The results showed that to obtain the maximum Chl (a+b) contents for most tree species extracted by 80% acetone and 95% ethanol required a minimum of 18 h, while the incubation periods by DMSO were 2-6 h and 18-32 h to extract 90% of the Chl from the broadleaved and coniferous tree species, respectively. We observed that the amount of Chl extracted with DMSO was significantly higher than that extraction with 80% acetone and 95% ethanol, particularly for conifer species with the exception of Phellodendron amurense, Fraxinus mandshurica, and Tilia amurensis, in which the maximum amount of Chl was extracted with acetone. The DMSO extracted Chl in exhibited the lowest degree of variation among the three solvents. The leaf mass area (LMA), leaf thickness, and diameter of the primary leaf vein were significantly negatively correlated with the Chl a, Chl b, and Chl (a+b) content for the 12 tree species. There were non-significant different slopes or intercepts between the curves for LMA and Chl a, Chl b, or Chl (a+b) at the different incubation times for the same solvent or the different solvents at the certain incubation time (P > 0.05).