Reproductive phenology and germination of Eleocharis laeviglumis R. Trevis. & Boldrini (Cyperaceae)

Abstract

Aquatic macrophytes are important components of freshwater ecosystems, of which Cyperaceae is the most diverse family. Many species of Cyperaceae form dense populations along lake margins of the southern coast of Brazil, but little is known about their sexual reproductive strategies. We characterized the reproductive life cycle of Eleocharis laeviglumis, an abundant emergent macrophyte of coastal wetlands in southern Brazil, by assessing its reproductive phenophases and estimating the number of its flowers and potentially viable fruits per inflorescence in a natural population. We also tested seed germinability and vigor for a period of four months during a single reproductive season. The species possesses dichogamous and protogynous spikelets with an average duration of 34 days (preanthesis, 1.7 d; anthesis, 6.9 d; fruit maturation, 22.3 d; fruit dispersion, 3.2 d). More than half of the flowers (62.2 %) developed into fruits, while only 5.5 % of the seeds germinated. Germinability and vigor decreased during the reproductive season. Some culms probably originate from asexual reproduction or sexual reproduction of clones. For restoration purposes, we suggest that E. laeviglumis should be propagated by sowing seeds collected at the beginning of the reproductive season, along with the transplantation of rhizomes.

Contrasting reproductive strategies despite convergent traits for two dryland river-floodplain species

“…In E. acuta, only one pair of samples were in a parent-offspring relationship through self-fertilisation, suggesting that while this species can reproduce via self-fertilisation, mechanisms to reduce selffertilisation such as dichogamy, observed in E. laeviglumis (Demeda et al 2018) exist. Other mechanisms to promote outcrossing also exist in the Cyperaceae such as self-incompatibility in Rhynchospora ciliata (Costa and Machado 2012).…”

“…In E. acuta , only one pair of samples were in a parent-offspring relationship through self-fertilisation, suggesting that while this species can reproduce via self-fertilisation, mechanisms to reduce self-fertilisation such as dichogamy, observed in E. laeviglumis (Demeda et al . 2018) exist.…”

“…All members of the Cyperaceae are wind pollinated (Walters 1949). While the timing of spikelet maturity is unknown for E. acuta , the spikelet of E. laeviglumis from southern Brazil is dichogamous and protogynous with reproductive organs maturing at different times (Demeda et al . 2018) which reduces self-pollination and promotes out-crossing.…”

Reproductive Strategies and Population Genetic Structure in Two Dryland River Floodplain Plants, Marsilea drummondii and Eleocharis acuta

“…In E. acuta, only one pair of samples was in a parent–offspring relationship through self-fertilisation, suggesting that while this species may reproduce via self-fertilisation, mechanisms to reduce self-fertilisation such as dichogamy, as observed in E. laeviglumis [ 46 ], exist. Other mechanisms to promote outcrossing also exist in the Cyperaceae , such as self-incompatibility in Rhynchospora ciliata [ 64 ].…”

“…All members of the Cyperaceae are wind-pollinated [ 45 ]. While the timing of spikelet maturity is unknown for E. acuta , the spikelet of E. laeviglumis from southern Brazil is dichogamous and protogynous, with its reproductive organs maturing at different times [ 46 ], which reduces self-pollination and promotes out-crossing.…”