FEATURED NEWS
Special Issues Are Dedicated to Duckweed Research and Applications
Duckweeds (Lemnaceae), the fastest growing angiosperms, are increasingly gaining attention as potential crop plants for production of biomass. The availability of genome sequence data and effective techniques for genetic transformation in this plant family attracts researchers to reconsider their lost legacy as model plants. The January 2015 Plant Biology Special Issue presents interesting papers about duckweed systematics, physiology, molecular biology, biotechnology and heavy metal toxicity and is dedicated to late Elias Landolt (1926-2013), the “father” of modern duckweed research.
More recent Special Issues: November 2020 Frontiers in Sustainable Food Systems September 2023 Plants A comprehensive review on duckweed in October 2021 Plant Cell More documents from FAO, the United Nations |
ISCDRA NewslettersThe International Steering Committee on Duckweed Research and Application (ISCDRA) was formed in August 2013 to guide the work of the duckweed community and help organize the biennial International Conference on Duckweed Research and Applications (ICDRA). In addition, it publishes a quarterly newsletter since October 2013. This newsletter was renamed the Duckweed Forum (DF) along with a new cover design in October 2015. Read the latest news as well as the back issues of the DF below.
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What Is Duckweed?Duckweed is a family of aquatic plants that float on the surface of lakes and waterways worldwide. It grows in a variety of climates from Siberia to the tropics. Five genera of duckweed, including 37 species, have been identified. The Wolffia genus contains the smallest known flowering plants on earth.
Representative species from the 5 genera of duckweed. Click image to enlarge.
As its name implies, duckweed is eaten by ducks—as well as other animals—and behaves much like a weed: it multiplies rapidly, especially on water rich with nutrients such as nitrogen and phosphate.
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Applications of DuckweedSeveral properties of duckweed make it highly attractive for environmental and agricultural applications:
Farming duckweed. Rutgers PhD student Philomena Chu sets up floating barriers to contain duckweed grown on a horticultural runoff pond in Columbus, NJ.
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What is the true number of duckweed species?
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By Eric Lam, RDSC Director
This recurring question has often come up in discussions with colleagues and students. The two numbers that have been quoted have been 38 and 37. After a discussion with Klaus Appenroth, it is confirmed that it should be 37. Although a paper in 2002 from Don Les' group listed 38 species, Lemna ecuadoriensis was combined with Lemna obscura by Elias Landolt. This was subsequently supported by the recent AFLP analysis results from the Appenroth lab (Planta 2010) where 84 clones of Lemna were compared. I hope this comment will help to lessen the confusion in the field and stimulate additional discussions if necessary. (from ~ 2021) An update on the current number of duckweed species (Oct. 2024) Since the previous work almost 15 years ago had resulted in the fusion of L. ecuadoriensis with L. obscura into a single species, the more recent investigation by Bog et al. (Taxon 2020) has led to the conclusion that L. yungensis and L. valdiviana are likely a single species. In addition to plastidic barcoding and AFLP analysis, metabolomics was also used to determine that these isolates are not distinguishable. Thus, they are now merged as well under the older species name of L. valdiviana. The current recognized species number is thus 36. In addition to these corrections that are enabled by application of new technologies, recent application of the nuclear genome-based TBP (Tubulin-Based Polymorphism) barcoding method by Braglia et al. (Front. Plant Sci. 2021) and whole genome sequencing of Lemna populations by Ernst et al. (BioRxiv 2023) over the past 4 years have conclusively shown the existence of natural hybrids in this genus. The first well-characterized example is that of the species L. japonica, which has been revealed as natural hybrids between the species of L. minor and L. turionifera. To indicate this relationship, the nomenclature of Lemna x japonica as shown in Braglia et al. (Plants 2021) is recommended. |
Phylogeny of the duckweed family |
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Watch Duckweed GrowSpirodela polyrhiza grown on filtered wastewater from Princeton Meadows Wastewater Treatment Plant. This strain (# 9316) was originally collected from a lake in Ajmer, India. Duckweed is one of the fastest growing plants on earth. It uses asexual reproduction to multiply rapidly on nutrient-rich water. In the process, it absorbs the dissolved nutrients and purifies the water.
Photography by Ryan Gutierrez and Philomena Chu, Laboratory of Eric Lam, Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey.
More videos from World of Duckweed. |
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The branching and flowering of Wolffia australiana Cultivated and shot by Feng Li, Leyao Qi, and Sina A; Post production made by Yuanyuan Li; Directed by Shunong Bai (School of Life Sciences, Peking University; The High School Affiliated to Renmin University of China). More videos from World of Duckweed. |
