Germination and sporophytic development of Regnellidium diphyllum Lindm. (Marsileaceae) in the presence of copper

Abstract

Regnellidium diphyllum Lindm. is a heterosporous fern growing in wetlands and humid soils that are being converted to agricultural activities. Many products that are used in agriculture contain copper, resulting in surface and groundwater contamination. Germination and initial development tests were performed using Meyer's solution containing copper sulphate at concentrations of 0 (control), 1, 5, 10, 50 and 100 mg L −1 . Th e experiment was conducted in a growth chamber at 25 ± 1°C for 28 days, with a 12/12-hour light/dark cycle and a photon fl ux density of 100 μmol m −2 s −1. Th e lowest germination rate (6%) was observed at 100 mg L −1 . Primary root growth was signifi cantly reduced at ≥ 10 mg L −1 . Secondary leaves of sporophytes grown in concentrations ≥ 5 mg L −1 were progressively shorter than were those formed by the control plants. We conclude that the release of pollutants containing copper into the natural habitats of R. diphyllum can cause phytotoxicity, threatening the establishment of populations and worsening the already vulnerable conservation status of this species.

Geochemical Analysis of Cretaceous Shales from the Hazara Basin, Pakistan: Provenance Signatures and Paleo-Weathering Conditions

“…While copper is required in minimal amounts for both plants and animals, its excessive concentration may be hazardous. Copper concentrations over a certain level may result in stunted development and chlorosis [65]. Although chromium is neither needed nor useful for plants, it is necessary for trace amounts for mammals.…”

Lead tolerance and accumulation in initial sporophytes of Regnellidium diphyllum Lindm. (Marsileaceae)

“…Increasing concentrations of nickel (0.05 to 100 mg L -1 ) were also associated with a decrease in germination percentage from 75 to 45% (Kieling-Rubio et al, 2012). Lower germination percentages (of approximately 49%) were also observed in megaspores exposed to 50 mg L -1 copper (Cassanego et al, 2013).…”

“…The length of roots, primary and secondary leaves was also shorter in sporophytes exposed to nickel concentrations of 3.2 and 4.8 mg L -1 than in sporophytes not exposed to nickel (Kieling-Rubio et al, 2012). Cassanego et al (2013) observed significant negative effects on the development of R. diphyllum sporophytes grown in media with copper concentrations of 5 mg L -1 and higher. The visible symptoms of root necrosis in cultures exposed to higher concentrations of lead can be at least partially explained by the excess of lead in the nutrient medium, which can lead to reduction in plant growth, inhibition of photosynthesis, cell injury and tissue necrosis, and might even be lethal (Sharma and Dubey, 2005).…”

“…Currently, R. diphyllum is considered an endangered species in Rio Grande do Sul, and is classified as vulnerable (Rio Grande do Sul, 2003). The species' sensitivity to pollutants has only recently begun to be investigated (Wunder et al, 2009;Kieling-Rubio et al, 2010Droste et al, 2010;Cassanego et al, 2010Cassanego et al, , 2013. The present study aimed to assess the influence of lead on germination and on the initial development of R. diphyllum, so as to contribute to the understanding of the impact of this heavy metal on the establishment of young sporophytes.…”

Growth and tolerance of Ilex paraguariensis A. St.-Hil. inoculated with ectomycorrhizal fungi in copper-contaminated soil

“…Fabaceae with up to 450 mg kg -1 of Cu added to the soil. Plants submitted to high doses of Cu may show shoot chlorosis (Yruela, 2013), early defoliation, and reduced shoot (Grassi Filho, 2005;Cassanego et al, 2013) and plant growth (Gautam et al, 2016). However, Steffen et al (2012) showed that the application of both the isolate UFSC-PT116 and eucalyptus essential oil increases the development of the aerial part of Caesalpinia peltophoroides Benth.…”