3
Worldwide Genetic Resources
of Duckweed: Stock Collections
K. S. Sree and K.-J. Appenroth
Abstract
Duckweeds are aquatic monocotyledonous
plants that include the smallest and the fastest
growing angiosperms known till date. The
family Lemnaceae presently includes 36
accepted species of duckweeds categorized into
five genera. Although having the capacity to
flower, these unique aquatic plants usually
propagate by vegetative means producing
clones. It has already been known through
various reports that duckweed plants although
belonging to the same species collected from
different geographical locations have variations
not only in their genetic properties but also in
their physiological properties, which is important for many of the practical applications of this
plant family. Hence, collection and maintenance of different clones of the same species
from different locations are important. The
international duckweed clonal collections from
around the world help the duckweed community by maintaining the clones, characterizing
their species identity and providing the required
genetic resources to the users for research and
application purposes.
3.1 Introduction
Duckweeds, because of their miniature size and
unique structure, had gained attention of the
researchers as early as eighteenth (von Linnaeus
1753) and nineteenth centuries (Schleiden 1839;
Griffith 1851; Hegelmaier 1868). This was a time
when some of the species of duckweeds were just
discovered and some were still hidden. The
researchers of this time had worked in great
details on morphology and anatomy of duckweeds of different species collected worldwide,
with the then-available tools. In this tradition, the
two-volume monographic study of Lemnaceae
by Landolt (1986), and Landolt and Kandeler
(1987) pronounced the use of duckweeds as
model plants for physiological investigations
during the twentieth century.
Duckweeds are free-floating, aquatic monocotyledonous flowering plants that inhabit the
lentic ecosystems like ponds, pools, lakes and so
on. These plants have the distinction to include
the smallest angiosperm and the fastest growing
angiosperm known till date on earth (Sree et al.
2015b; Ziegler et al. 2015). The anatomy of
duckweeds is highly miniaturized and reduced,
with the smallest one majorly constituting a ball
of parenchymatous cells with a meristematic zone
K. S. Sree (&)
Department of Environmental Science, Central
University of Kerala, Periye 671316, India
e-mail: ksowsree9@cukerala.ac.in;
ksowsree@gmail.com
K.-J. Appenroth
Matthias Schleiden Institute—Plant Physiology,
Friedrich Schiller University of Jena, 07743 Jena,
Germany
e-mail: Klaus.Appenroth@uni-jena.de
© Springer Nature Switzerland AG 2020
X. H. Cao et al. (eds.), The Duckweed Genomes, Compendium of Plant Genomes,
https://doi.org/10.1007/978-3-030-11045-1_3
39
Worldwide Genetic Resources
of Duckweed: Stock Collections
K. S. Sree and K.-J. Appenroth
Abstract
Duckweeds are aquatic monocotyledonous
plants that include the smallest and the fastest
growing angiosperms known till date. The
family Lemnaceae presently includes 36
accepted species of duckweeds categorized into
five genera. Although having the capacity to
flower, these unique aquatic plants usually
propagate by vegetative means producing
clones. It has already been known through
various reports that duckweed plants although
belonging to the same species collected from
different geographical locations have variations
not only in their genetic properties but also in
their physiological properties, which is important for many of the practical applications of this
plant family. Hence, collection and maintenance of different clones of the same species
from different locations are important. The
international duckweed clonal collections from
around the world help the duckweed community by maintaining the clones, characterizing
their species identity and providing the required
genetic resources to the users for research and
application purposes.
3.1 Introduction
Duckweeds, because of their miniature size and
unique structure, had gained attention of the
researchers as early as eighteenth (von Linnaeus
1753) and nineteenth centuries (Schleiden 1839;
Griffith 1851; Hegelmaier 1868). This was a time
when some of the species of duckweeds were just
discovered and some were still hidden. The
researchers of this time had worked in great
details on morphology and anatomy of duckweeds of different species collected worldwide,
with the then-available tools. In this tradition, the
two-volume monographic study of Lemnaceae
by Landolt (1986), and Landolt and Kandeler
(1987) pronounced the use of duckweeds as
model plants for physiological investigations
during the twentieth century.
Duckweeds are free-floating, aquatic monocotyledonous flowering plants that inhabit the
lentic ecosystems like ponds, pools, lakes and so
on. These plants have the distinction to include
the smallest angiosperm and the fastest growing
angiosperm known till date on earth (Sree et al.
2015b; Ziegler et al. 2015). The anatomy of
duckweeds is highly miniaturized and reduced,
with the smallest one majorly constituting a ball
of parenchymatous cells with a meristematic zone
K. S. Sree (&)
Department of Environmental Science, Central
University of Kerala, Periye 671316, India
e-mail: ksowsree9@cukerala.ac.in;
ksowsree@gmail.com
K.-J. Appenroth
Matthias Schleiden Institute—Plant Physiology,
Friedrich Schiller University of Jena, 07743 Jena,
Germany
e-mail: Klaus.Appenroth@uni-jena.de
© Springer Nature Switzerland AG 2020
X. H. Cao et al. (eds.), The Duckweed Genomes, Compendium of Plant Genomes,
https://doi.org/10.1007/978-3-030-11045-1_3
39