Aquatic
Plant Toxicity Test Using Lemna spp., Tiers I and II
"This guideline is one of a series of test guidelines that have
been developed by the Office of Prevention, Pesticides and
Toxic Substances, United States Environmental Protection Agency for
use in the testing of pesticides and toxic substances, and the
development of test data that must be submitted to the Agency
for review under Federal regulations."
This test incorporates the test substance into the Lemna growth
medium.
For one view of this test, see Lewis, Michael A. (1995) "Use of
Freshwater Plants in Phytotoxicity Testing: A Review." Environ.
Pollut. 87(3):319-336. [ link to
abstract ]
Foliar exposure and incorporation of test substances into
sediments are also contemplated for future EPA testing in Lemna.
Foliar exposure
from the air may be more toxic to aquatic plants than aqueous
exposure. For a spray protocol, see: Lockhart, L.W.,
B.N. Billeck and C.L. Baron. 1989. "Bioassays with a floating aquatic
plant (Lemna minor) for
effects of sprayed and dissolved glyphosate." Hydrobiologia.
188/189:
353-359. [ summary of method
]
"A Sediment Toxicity Method Using Lemna Minor, Duckweed"
a poster presentation (Society of Environmental Toxicology and
Analytical Chemistry meeting, Nashville, Tennessee, November, 2000) by
Lazorchak, J.M., Williams, D.E., Suszcynsky-Meister, E.M. and Smith,
M.E., U.S. EPA and SBI Environmental, Cincinnati, OH.
"A sediment toxicity method using Lemna minor (duckweed). We
developed a Lemna minor sediment toxicity test method to assess
sediment contaminants which may affect plants. In addition to the
duckweed method, sediments were also tested using a miniaturized
freshwater amphipod method and a fathead minnow embryo/ larval (FHM)
survival test. Of the three endpoints used in duckweed tests, results
indicated that chlorophyll a was a more sensitive measure than either
frond number or wet weight. A sediment reference toxicant method has
been developed for KCl and Atrazine. The duckweed method is convenient
to use and provides an additional sediment toxicity indicator."
- American Society for Testing of Materials
"Biological Test Method: Test for Measuring the Inhibition of Growth
Using the Freshwater Macrophyte, Lemna Minor"
"The endpoints for the test are frond number and frond dry weight
at the end of a 7-day toxicity test. Procedures are given for culturing
L. minor in the laboratory. General or universal conditions
and procedures are outlined for testing various substances for their
effects on Lemna growth. Additional conditions and procedures
are stipulated, which are specific for testing samples of chemical,
effluent, elutriate, leachate, or receiving water. Instructions and
requirements are included on apparatus, facilities, handling and
storing samples, preparing test solutions and initiating tests,
specific test conditions, appropriate observations and measurements,
endpoints, methods of calculation, validation, and the use of reference
toxicants."
EPS 1/RM/37E
21.5 x 28 cm - 118 p. - 1999 · Cat. No. EN49-24/1-37E ·
ISBN 0-660-17894-X
Canada CAN$ 25.00 · Other Countries US$ 25.00
[ Information
on purchasing this book ] - From this link, you must search on
"Lemna." The Lemna method will appear in the list of search
results.
- German Test
(DIN ISO Standard) DIN AK "Bioteste",
Vorlage für einen ISO/CEN Entwurf zum Lemnatest (ISO/WD 20079)
(Stand: 04.05.2001)
This method is written in English and includes a very valuable
list of
definitions. For example, frond and frond number:
3.7 Frond
Frond is an individual leaf-like structure on a duckweed colony. It is
the smallest unit,
(i. e. individual) capable of reproducing.
3.19 Frond number
According to this standard all fronds protruding from a mother frond
which is directly
visible without magnification from above.
- Swedish Test
Swedish National Environmental Protection Board, 1990. "Method for
toxicity test with the floating plant, Lemna minor,"
Duckweed. SNV report 3755.
"Image
processing for biology" Matthias Eberius of
LemnaTec writes, "We have developed a computerized image
analysis system
for the Lemna growth inhibition test (as standardized by ASTM,
OECD
and soon by ISO). The core of the LemnaTec Scanalyzer is software
to
quantify Lemna images, including their number, color, frond
area
and other measures. The system provides GLP-compliant documentation and
will
support the overall management of the bioassay. The use of this
system
raises data quality and reduces the costs of measurement and
documentation. For cost-effective and flexible use, our clients
can choose from purchase of the complete system or image analysis
service on a confidential fee-for-service basis. High quality
digital images may be sent to us via the Internet for analysis, which
eliminates the need for purchase of a complete system. Tools for
analysis of other bioassays are also available."
