The genus Ruppia L. (Ruppiaceae) in the Mediterranean region: An overview

Abstract

This paper reviews the current knowledge on the diversity, distribution and ecology of the genus Ruppia L. in the Mediterranean region. The genus Ruppia, a cosmopolitan aquatic plant complex, is generally restricted to shallow waters such as coastal lagoons and brackish habitats characterized by fine sediments and high salinity fluctuations. In these habitats Ruppia meadows play an important structural and functional role. Molecular analyses revealed the presence of 16 haplotypes in the Mediterranean region, one corresponding to Ruppia maritima L., and the others to various morphological forms of Ruppia cirrhosa (Petagna) Grande, all together referred to as the “R. cirrhosa s.l. complex”, which also includes Ruppia drepanensis Tineo. Populations of hybrid origin between R. maritima and R. cirrhosa and polyploidy have been detected

Strong bottlenecks, inbreeding and multiple hybridization of threatened European Ruppia maritima populations

“…As a consequence of apparent uncertainties at world scale level, no reliable distribution range maps of Ruppia species could be made available (Short et al, 2007). In a recent overview of the Mediterranean Ruppia (Mannino et al, 2015) the revised taxon identity was taken into account as much as possible and allowed to describe the growth cycle, ecology, biomass and production for R. cirrhosa and R. maritima. Annual production of R. cirrhosa as a function of water depth could be evidenced (Mannino et al, 2015).…”

“…In a recent overview of the Mediterranean Ruppia (Mannino et al, 2015) the revised taxon identity was taken into account as much as possible and allowed to describe the growth cycle, ecology, biomass and production for R. cirrhosa and R. maritima. Annual production of R. cirrhosa as a function of water depth could be evidenced (Mannino et al, 2015). Nonetheless, all publications on ecology of R. maritima from various continents would require a careful revision to which extent these studied populations refer to the same evolutionary significant unit.…”

Lagoons and saltwater wetlands getting more diversity: A molecular approach reveals cryptic lineages of a euryhaline submerged macrophyte (Ruppia)

“…Focus has been too long on two species despite a wide variety of strategies for survival (Mannino et al, 2015): selfing, outcrossing, clonal persistent, annual, large reproductive allocation (many-seeded), poorseeded, germination features and so forth, that eventually might be attributed to a very large phenotypic plasticity but seems to be contradicted by present findings of genetic differentiation. Microsatellite markers will be useful to determine connectivity levels and con- (Jackson, 2017), which refers in the case of Ruppia to various saltwater lagoon and brackish wetland types, including humanaltered environments such as saltwork areas and surrounding water infrastructure.…”

“…Individuals belonging to R. maritima and R. drepanensis were considered diploid, whereas tetraploidy was observed in most other taxa (Martinez‐Garrido et al, ; Triest & Sierens, , ). When used in ecological studies, populations containing different ploidy levels or cryptic species could lead to inaccurate estimations of, for example, annual versus perennial survival strategies or biomass allocation in belowground and aboveground structures (Mannino et al, ). A better understanding of the autoecology of Ruppia populations in a diverse range of permanent and ephemeral saltwater habitats will benefit from unambiguous identification of gene pools and species.…”

An update on morphology and distribution of Ruppia filifolia (Philippi) Skottsberg in the Magellan region, southern Chile

“…The taxonomy of Ruppia species is not fully resolved because of an inherent high plasticity in morphology that results from the frequent occurrence of hybrids and polyploids (Mannino et al, 2015). Ruppia L., a cosmopolitan genus of aquatic plants, is classified either in the euryhaline family of Potamogetonaceae (Gamerro, 1968;Den Hartog, 1981;Jacobs & Brock, 1982) or in the monogeneric group of the Ruppiaceae (Cronquist, 1981;Les et al, 1997).…”