1021-4437/03/5003- $25.00 © 2003
Russian Journal of Plant Physiology, Vol. 50, No. 3, 2003, pp. 395–397. From Fiziologiya Rastenii, Vol. 50, No. 3, 2003, pp. 442–444.
Original English Text Copyright © 2003 by Kapotis, Zervoudakis, Veltsistas, Salahas.
A SPAD-502 chlorophyll meter determines the rel-
ative amount of leaf TCHL in intact plant leaves (in a
rapid and nondestructive manner) by measuring the
intensity of light transmitted through the leaf at two
wavelengths. The obtained “SPAD values” have been
positively correlated with destructive chlorophyll mea-
surements in several crops, such as rice , wheat ,
soybean  and others [4–7].
There is no evidence correlating SPAD values with
leaf TCHL concentration from any weeds. Moreover,
the correlation between SPAD values and the physio-
logical parameters of the plant leaves has been poorly
is a common widespread weed in
Greek ﬁelds and the present study was carried out to
investigate the usefulness of the SPAD meter for the
estimation of TCHL content in the leaves of this plant.
In addition, the correlation between SPAD values and
some physiological parameters of the leaves was stud-
ied under ﬁeld conditions.
MATERIALS AND METHODS
At the beginning of summer 2001,
L. plants growing in great abundance in Mesologgi
ﬁelds, near Technological Institute, were studied. Fully
developed young leaves varying in greenness (chloro-
phyll content) were marked and used as plant material.
The experimental protocol was the following: after
nondestructive ﬁeld measurements of the photosynthe-
sis, the transpiration rate, the stomatal conductance and
SPAD-502 chlorophyll meter (Minolta Camera Co.,
Japan) readings, leaves were collected from the plants,
wrapped in plastic bags and transferred immediately to
the lab for TCHL estimation in the extracts.
The SPAD-502 meter utilizes two light-emitting
diodes (650 and 940 nm) and a photodiode detector to
sequentially measure transmission of red and infrared
light through leaves. The obtained “SPAD values” are
proportional to the chlorophyll content of the leaves.
The instrument has to be calibrated against actual chlo-
rophyll concentrations measured by the standard spec-
trophotometric methods. It measures,
ual leaves in just a couple of seconds and averages a
series of measurements per leaf.
Photosynthetic rate, transpiration and stomatal con-
ductance were measured with the LCI Portable Photo-
synthesis System (ADC, BioScientiﬁc Ltd., England)
before midday at 30–32
C and 1500
ral light. In this system, CO
was measured by infrared
gas analyzer and H
O was recorded with two laser
trimmed humidity sensors. The system also measures
leaf temperature, chamber air temperature and irradi-
Subsequently, the mean of 10 readings per leaf mea-
sured with SPAD-502 portable chlorophyll meter, was
Finally, two discs (0.9 cm in diameter) from each
leaf were incubated with 3 ml DMSO (99.5% or
14.08 M) in a glass tube at 65
C for 80 min until the tis-
sue became colorless. The absorbance at 665 and 648 nm
was determined with a spectrophotometer Shimadzu-
Comparison of Chlorophyll Meter Readings
with Leaf Chlorophyll Concentration in
Correlation with Physiological Processes
G. Kapotis, G. Zervoudakis, T. Veltsistas, and G. Salahas
Department of Greenhouse Crops and Floriculture, Technological Institute of Mesologgi, Nea Ktiria 30200, Mesologgi, Greece;
fax: +(3263) 105-8209; e-mail: G.Zervoudakis@biology.upatras.gr
Received April 16, 2002
—The portable chlorophyll meter (SPAD-502) has been successfully used for a rapid and direct esti-
mation of total chlorophyll content (TCHL) in the leaves of some crops. In this work, SPAD-502 meter readings
and TCHL concentration were compared for the leaves of
L., a common weed. SPAD read-
ings were linearly and positively correlated to TCHL concentration in the leaves. A linear correlation was also
shown between SPAD-502 readings and some physiological parameters of the leaves, such as photosynthesis,
transpiration, and stomatal conductance.
Key words: Amaranthus vlitus - chlorophyll content - photosynthesis - transpiration - SPAD-502 readings
: TCHL—total chlorophyll.
This article was submitted by the authors in English.