Diversity and Differentiation of Duckweed Species from Israel

Abstract

Duckweeds (Lemnaceae) are tiny plants that float on aquatic surfaces and are typically isolated from temperate and equatorial regions. Yet, duckweed diversity in Mediterranean and arid regions has been seldom explored. To address this gap in knowledge, we surveyed duckweed diversity in Israel, an ecological junction between Mediterranean and arid climates. We searched for duckweeds in the north and center of Israel on the surface of streams, ponds and waterholes. We collected and isolated 27 duckweeds and characterized their morphology, molecular barcodes (atpF-atpH and psbK-psbI) and biochemical features (protein content and fatty acids composition). Six species were identified—Lemna minor, L. gibba and Wolffia arrhiza dominated the duckweed populations, and together with past sightings, are suggested to be native to Israel. The fatty acid profiles and protein content further suggest that diverged functions have attributed to different haplotypes among the identified species. Spirodela polyrhiza, W. globosa and L. minuta were also identified but were rarer. S. polyrhiza was previously reported in our region, thus, its current low abundance should be revisited. However, L. minuta and W. globosa are native to America and Far East Asia, respectively, and are invasive in Europe. We hypothesize that they may be invasive species to our region as well, carried by migratory birds that disperse them through their migration routes. This study indicates that the duckweed population in Israel’s aquatic environments consists of both native and transient species.

Comparative Study on Fatty Acids Composition of Lemna minor (Duckweed) Cultured in Indoor Plastic Tanks and Outdoor Earthen Ponds

“…These included: linoelaidic, eicosanoic, EPA, and DHA (Table 2). Other researchers who analyzed L. minor from other regions did not detect the four FAs [15,16,18].…”

“…They exhibit high growth rates that cover ponds or lakes in a few days under favorable environmental conditions [11][12][13][14]. Despite the documentation of FAs profiles from wild L. minor populations [9,[14][15][16], there is a paucity of information on the quantitative variation of L. minor FAs composition in indoor and outdoor culture settings. Thus, the primary objective of this study was to identify and compare the FAs composition in L. minor cultured in indoor plastic tanks and outdoor fish ponds.…”

Cobalamin production in phototrophic and mixotrophic cultures of nine duckweed species (Lemnaceae)

“…The growth of L. delbrueckii could be inhibited by various compounds, such as proteins and fatty acids, that may be present in duckweed extracts (Partanen et al, 2001). Duckweed extracts were shown to be rich in fatty acids and non-polar components, such as carotenoids and phytosterols [12][13][14] . These compounds could have interfered with MBA tests with duckweed extracts.…”

“…Yet recently, the duckweed Wolffia globosa Mankai was reported to contain 2.8 ± 0.5 µg cobalamin per 100 g dry weight 2 . Furthermore, duckweed species of the genus Wolffia were found to be highly nutritious, containing large amounts of protein, omega-3 fatty acids, dietary fiber, polyphenols, iron, and several other micronutrients [12][13][14] . The nutritional benefits of W. globosa Mankai for human health were recently demonstrated [15][16][17][18][19] , including the benefits of the bioavailable cobalamin 2,20 .…”

Duckweed: Research Meets Applications

“…Interestingly, Lemna aequinoctialis did not form a uniform taxon, which might be a hint for the existence of hybrids. The same plastidic markers for barcoding were used by Yosef et al [ 15 ], identifying six different species from Israel. For several investigations, the knowledge of the number of chromosomes in the different duckweed species and clones is important, and Hoang et al [ 16 ] summarized it for all 36 duckweed species.…”