Given their clonal, exponentially fast reproduction, a key question is whether genome structure is conserved across the species in … Genome sizes in the five Lemnoideae genera span an order of magnitude from 158 Mb in Spirodela polyrhiza to 1,881 Mb in Wolffia arrhiza 7. S. polyrrhiza) is a species of duckweed known by the common names common duckmeat, greater duckweed, great duckmeat, common duckweed, and duckmeat. Spirodela polyrhiza, the Greater Duckweed, has the largest body plan yet the smallest genome size in the family (1C = 150 Mb). var. Its complete sequence of the mitochondrial (mt) genome could provide clues for the understanding of the evolution of mt genomes in plant. It produces several minute roots. Spirodela polyrhiza (orth. As one of the most yielding biomass species, they can be found from temperate to tropical regions, surviving in freshwater ponds and animal waste lagoons. It can be found nearly worldwide in many types of freshwater habitat. Spirodela polyrhiza is a fast‐growing aquatic monocot with highly reduced morphology, genome size and number of protein‐coding genes. S1). Its genome has only 19,623 predicted protein-coding genes, which is 28% less than the dicotyledonous Arabidopsis thaliana and 50% less than monocotyledonous rice ( Wang et al., 2014 ). The haploid genome size of S. polyrhiza 7003 has been estimated by flow cytometry to be similar to Arabidopsis thaliana at ~150 MB using Brachypodium distachyon (300 MB), Carica papaya (345 MB) and Physcomitrella patens (480 MB) as internal controls. Although a seed plant, Spirodela polyrhiza clones rarely flower and multiply mainly through vegetative propagation. Whole‐genome sequencing using different approaches and clones yielded two reference maps.
Each plant is a smooth, round, flat disc 0.5 to 1.0 cm wide. Spirodela polyrhiza (strain 7498) has a compact mitochondrial genome (about 228 kb) (Wang et al., 2012) and a very small nuclear genome (about 158 Mbp) (Wang et al., 2014). Here we select Spirodela polyrhiza for whole-genome sequencing. Spirodela polyrhiza is a species of the order Alismatales, which represent the basal lineage of monocots with more ancestral features than the Poales.

We show that Spirodela has a genome with no signs of recent retrotranspositions but signatures of two ancient whole-genome duplications, possibly 95 million years ago (mya), older than those in Arabidopsis and rice. Duckweeds are the fastest growing angiosperms and have the potential to become a new generation of sustainable crops. Considering these biological features of Spirodela and its basal position in the monocot lineage, understanding its genome architecture could shed light on plant adaptation and genome evolution. It also produces a pouch containing male and female flower… Greater duckweeds, i.e., Spirodela polyrhiza, are small and fast-growing aquatic plants, belonging to the early-diverging monocot order of the Alismatales (SI Appendix, Fig. It is a perennial aquatic plantusually growing in dense colonies, forming a mat on the water surface.