Acta Univ Latv (2007) 723: 145–154

Nondestructive methods in plant biology: an accurate measurement of chlorophyll content by a chlorophyll meter

Abstract

Nondestructive methods of plant analysis are becoming increasingly popular in plant biology. Optical measurement of leaf chlorophyll content allows to produce reliable results without destructive sampling. The aim of the present investigations was to validate the use of an absorbancebased chlorophyll meter in different fields of plant biology. A near-linear relationship was found between spectrophotometrically determined total chlorophyll content on fresh mass basis and SPAD values measured by a chlorophyll meter for all of the tested plant species. In experiments with galled plant tissues localized changes in chlorophyll content in the infested leaf indicated a significant effect of the gall-former on photosynthesis Ulmus laevis. A contrasting effect of the level of gall infestation on photosynthesis-related characteristics was revealed in studies with Salix fragilis and Tilia platyphyllos. A pronounced rhythmicity of chlorophyll content in leaves of bean seedlings allowed to characterize an endogenous circadian rhythm in photosynthetic activity. Changes in chlorophyll content in leaves of wheat plants were used as an early indicator to predict the effectivity of application of different foliar fertilizers. The obtained results support the potential usage of nondestructive chlorophyll measurement by chorophyll meter in various branches of plant biology, including ecophysiology, plant physiology, and agricultural sciences, when appropriate accurate calibration of SPAD readings against spectrophotometrically determined total chlorophyll content is made for every particular species.