title: Flood induced phenotypic plasticity in amphibious genus Elatine (Elatinaceae).
abstract: Vegetative characters are widely used in the taxonomy of the amphibious genus Elatine L. However, these usually show great variation not just between species but between their aquatic and terrestrial forms. In the present study we examine the variation of seed and vegetative characters in nine Elatine species (E. brachysperma, E. californica, E. gussonei, E. hexandra, E. hungarica, E. hydropiper, E. macropoda, E. orthosperma and E. triandra) to reveal the extension of plasticity induced by the amphibious environment, and to test character reliability for species identification. Cultivated plant clones were kept under controlled conditions exposed to either aquatic or terrestrial environmental conditions. Six vegetative characters (length of stem, length of internodium, length of lamina, width of lamina, length of petioles, length of pedicel) and four seed characters (curvature, number of pits / lateral row, 1st and 2nd dimension) were measured on 50 fruiting stems of the aquatic and on 50 stems of the terrestrial form of the same clone. MDA, NPMANOVA Random Forest classification and cluster analysis were used to unravel the morphological differences between aquatic and terrestrial forms. The results of MDA cross-validated and Random Forest classification clearly indicated that only seed traits are stable within species (i.e., different forms of the same species keep similar morphology). Consequently, only seed morphology is valuable for taxonomic purposes since vegetative traits are highly influenced by environmental factors.
authors.affiliation: Department of Botany, University of Debrecen, Debrecen, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Molnár V
authors.affiliation: MTA-DE, "Lendület" Behavioural Ecology Research Group, University of Debrecen, Debrecen, Hungary.
authors.forename: János Pál
authors.initials: JP
authors.lastname: Tóth
authors.affiliation: Department of Botany, University of Debrecen, Debrecen, Hungary.|MTA-ELTE-MTM Ecology Research Group, Budapest, Hungary.
authors.forename: Gábor
authors.initials: G
authors.lastname: Sramkó
authors.affiliation: Department of Botany, University of Debrecen, Debrecen, Hungary.
authors.forename: Orsolya
authors.initials: O
authors.lastname: Horváth
authors.affiliation: Department of Botany and Nature Conservation, University of Szczecin, Szczecin, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Popiela
authors.affiliation: Department of Botany, University of West-Hungary, Sopron, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Mesterházy
authors.affiliation: Department of Tisza Research, MTA Centre for Ecological Research, Debrecen, Hungary.
authors.forename: Balázs András
authors.initials: BA
authors.lastname: Lukács
keywords: Adaptation; Cultivation experiments; Macrophyte; Morphological variability; Seed characters; Seed-morphology; Vegetative characteristics; Water depth; Wetland ephemerophytes