Abstract
Plastic responses of 10 aquatic plant species from 5 rivers and 5 lakes in NW Poland were examined. <em>Chara fragilis</em>, <em>C. delicatula</em>, <em>Potamogeton pectinatus</em>, <em>P. perfoliatus</em>, <em>P. natans</em>, <em>Spirodela polyrhiza</em>, <em>Hydrocharis morsus-ranae</em>, <em>Salvinia natans</em>, <em>Nymphoides peltata</em> and <em>Juncus bulbosus</em> were the subject of research. In the running water of rivers, rhizophytes were generally bigger and they allocated from 0.6% to 58.6% more biomass for anchoring in the substrate than in stagnant water (ox bow lakes). In both flow variants rhizophytes allocated a similar biomass fraction for generative reproduction. On the other hand, under the influence of water flow pleustophytes reduced the mass of an individual (<em>Spirodela</em> by 25%, <em>Hydrocharis</em> 67%, <em>Salvinia</em> 77%) and emergent structures (p&lt;0.001), and the number of sporangia (p&lt;0.001). In both flow variants the input of biomass to generative reproduction was the same (<em>Salvinia</em>), or it was greater in running water (<em>Hydrocharis</em>; an increase from 4.9±1.3% to 15.1±3.6%). Under the conditions of strong wave action, in comparison with the lack of this environmental factor, <em>Chara delicatula</em> was several times shorter (p&lt;0.001). However, it was also stouter, and as a result it had similar mass. In the areas of wave action the plant allocated 88.8% of its mass for anchoring in the substrate, whereas when there were no waves, only 22.7%.
Highlights
The within-population variability of aquatic macrophytes is caused by environmental pressure, competition and genetic diversity of individuals, which result from many factors including different general-purpose or single-purpose genotypes, sensu Barrett et al (1993)
Samples for the variability analysis of ramets of 10 species of aquatic macrophytes came from 5 lowland rivers and 5 lakes (2 oligotrophic, 2 mesotrophic and 1 eutrophic)
The majority of aquatic macrophytes have a clonal structure and reproduce mainly by vegetative means (Sculthorpe 1967; Grace 1993; Szmeja 2006). This leads to low genetic diversity of a population (Hutchinson 1975; Hofsta et al 1995; Santamaría 2002)
Summary
The within-population variability of aquatic macrophytes is caused by environmental pressure, competition and genetic diversity of individuals, which result from many factors including different general-purpose or single-purpose genotypes, sensu Barrett et al (1993). Genetic diversity of local populations is usually low. Among populations it is common (Hofstra et al 1995; Akimoto et al 1998; Gornall et al 1998; Gao and Hong 2000). The low level of the former and high of the latter probably arise from asexual reproduction which is widespread in aquatic plants. According to Santamaría (2002), genetic variability of aquatic macrophytes is of rather secondary importance in local populations. If it turned out that such a statement is fully justified, the role of environmental heterogeneity in the plasticity of aquatic plants would acquire new meanings
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
