title: Response of Salvinia cucullata to high NH4(+) concentrations at laboratory scales.
abstract: Growth, morphology, NH(4)(+) uptake and mineral allocation in Salvinia cucullata Roxb. ex Bory grown with different amounts of NH(4)(+) were investigated. Plants of uniform size were grown on full strength Smart and Barko medium with different NH(4)(+) concentrations (0.5, 1, 5, 10 and 15 mM) and incubated in a greenhouse for four weeks. Salvinia cucullata grew well in the medium with 0.5-1 mM NH(4)(+) with a relative growth rate of 0.11-0.12 d(-1) without exhibiting NH(4)(+) toxicity symptoms. With an NH(4)(+) concentration above 5 mM, plant growth was suppressed and signs of NH(4)(+) toxicity were observed. NH(4)(+) toxicity symptoms were obvious in plants supplied with 10 mM and 15 mM NH(4)(+). These plants had low growth rates, short roots, low numbers of roots and showed chlorosis. Rotted roots and stems were also found in plants fed with 15 mM NH(4)(+). This species had a high uptake rate even though the NH(4)(+) concentrations increased, making it an ideal candidate for growth in eutrophic environments. The high NH(4)(+) concentration had a negative effect on K uptake resulting in low K concentration in the plant tissue, but the plants increased N content in plant tissue. Thus, harvested plants can be used as soil fertilizer or for animal feed. Furthermore, maintaining plant biomass can improve the efficiency of water treatment.
authors.affiliation: Department of Biology, Faculty of Science, Chiang Mai University, Meuang, Chiang Mai 50202, Thailand. Electronic address: ajampeetong@yahoo.com.
authors.forename: Arunothai
authors.initials: A
authors.lastname: Jampeetong
authors.affiliation: Department of Bioscience, Plant Biology, Aarhus University, Ole Worms Allé 1, 8000 Aarhus C, Denmark.
authors.forename: Hans
authors.initials: H
authors.lastname: Brix
authors.affiliation: Department of Environmental Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200, Thailand.
authors.forename: Suwasa
authors.initials: S
authors.lastname: Kantawanichkul
mesh_terms: D000641:Ammonia / Q000378:metabolism / Q000633:toxicity*; D018533:Biomass; D002734:Chlorophyll / Q000378:metabolism; D029624:Ferns / Q000187:drug effects* / Q000502:physiology; D018517:Plant Roots / Q000187:drug effects / Q000502:physiology; D012987:Soil / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*
chemical_list: D012987:Soil; D014874:Water Pollutants, Chemical; D002734:Chlorophyll; D000641:Ammonia