Relative in vitro growth rates of duckweeds (Lemnaceae) – the most rapidly growing higher plants

Abstract

Relative growth rates (RGR), doubling times (DT) and relative weekly yields (RY) of 39 clones (ecotypes) from 13 species representing all five genera of duckweeds were determined under standardised cultivation conditions. RGR ranged overall from 0.153 to 0.519 day(-1) , DT from 1.34 to 4.54 days and RY from 2.9 to 37.8 week(-1) . The RGR and RY data can be compared directly to other published findings to only a limited extent on account of missing clonal designations for and limited accessibility to previously investigated clones, as well as the use of different data denominators. However, they are consistent with the published results of other comparative duckweed studies of similar scope in showing that RGR does not vary primarily at the level of the genus or species, but rather reflects the adaptation of individual clones to specific local conditions. The RGR data support the widely held assumption that duckweeds can grow faster than other higher plants and that they can thus surpass land-based agricultural crops in productivity. Duckweeds are highly promising for the production of biomass for nutrition and energy, but extensive clonal comparison will be required to identify the most suitable isolates for this purpose.

How fast can angiosperms grow? Species and clonal diversity of growth rates in the genus Wolffia (Lemnaceae)

“…The previously published RGRs of 8 additional clones belonging to three of the Wolffia species (Ziegler et al 2015) were integrated in the present data in order to make the data set more comprehensive. Thus, in the present paper growth rates of 33 clones of different Wolffia species investigated under identical, standardized growth conditions were analyzed.…”

“…Consequently, clonal offsprings with identical genetic properties are produced. In a previous paper, we investigated rates of vegetative growth of 13 species of duckweeds belonging to all five genera, i.e., Spirodela, Landoltia, Lemna, Wolffiella, and Wolffia (Ziegler et al 2015). It was shown that the variation in vegetative growth rates exists at the level of clones rather than at the level of species or genera.…”

“…This holds true for the rate of biomass production, capacity of protein and starch accumulation in the biomass and so on. Some of the recent physiological investigations demonstrate that such natural variance exists not only exists between different duckweed species but also is intraspecific, i.e., between different clones (ecotypes) of the same species collected from different geographic locations of the world (Kuehdorf et al 2014;Ziegler et al 2015).…”

“…This family represents the smallest flowering plants (Landolt 1986;Bog et al 2013). More interesting, however, is the fact that they are gaining increasing importance in terms of their practical applications because of the following reasons: (1) they are the fastest growing angiosperms known till date (Ziegler et al 2015) producing high amounts of biomass which can be used as feedstock, e.g., for biogas production (Fedler and Duan 2011). (2) Under optimal growth conditions, i.e., light, temperature and nutrient availability, the resulting biomass contains high amounts of valuable proteins that makes it suitable for animal and human nutrition (Bhantumnavin and McGarry 1971;Appenroth et al 1982;Suppadit et al 2012;Zetina-Cordoba et al 2013). (3) When subjected to certain stress conditions, the protein content decreases but the starch content in the duckweed Communicated by L. A. Kleczkowski.…”

Taxonomy of duckweeds (Lemnaceae), potential new crop plants

“…Lemnaceae comprises one of the fastest growing angiosperms (Sree et al, 2015c;Ziegler et al, 2015). In some Asian countries, duckweeds have been used for human nutrition for generations (Bhanthumnavin and McGarry, 1971;cf.…”