title: Growth, morphology, ammonium uptake and nutrient allocation of Myriophyllum brasiliense Cambess. under high NH₄⁺ concentrations.
abstract: The effects of high NH(4)(+) concentration on growth, morphology, NH(4) (+) uptake and nutrient allocation of Myriophyllum brasiliense were investigated in hydroponic culture. The plants were grown under greenhouse conditions for 4 weeks using four levels of NH(4)(+) concentration: 1, 5, 10 and 15 mM. M. brasiliense grew well with a relative growth rate of c.0.03 day(-1) at NH(4)(+) concentration up to 5 mM. At the higher NH(4)(+) concentrations the growth of the plants was stunted and the plants had short roots and few new buds, especially when grown in 15 mM NH(4)(+) where the submerged leaves were lost and there were rotten roots and submerged stems. To avoid NH(4)(+) toxicity, the plants may have a mechanism to prevent cytoplasmic NH(4)(+) accumulation in plant cells. The net uptake of NH(4)(+) significantly decreased and the total N significantly increased in the plants treated with 10 and 15 mM NH(4)(+), respectively. The plant may employ NH(4)(+) assimilation and extrusion as a mechanism to compensate for the high NH(4)(+) concentrations. However, the plants may show nutrient deficiency symptoms, especially K deficiency symptoms, after they were exposed to NH(4)(+) concentration higher than 10 mM. The present study provides a basic ecophysiology of M. brasiliense that it can grow in NH(4)(+) enriched water up to concentrations as high as 5 mM.
authors.affiliation: Department of Biology, Faculty of Science, Chiang Mai University, Meuang, Chiang Mai, 50202, Thailand.
authors.forename: Piyanart
authors.initials: P
authors.lastname: Saunkaew
authors.forename: Prasit
authors.initials: P
authors.lastname: Wangpakapattanawong
authors.forename: Arunothai
authors.initials: A
authors.lastname: Jampeetong
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D018527:Hydroponics; D019684:Magnoliopsida / Q000187:drug effects* / Q000254:growth & development* / Q000378:metabolism*; D008903:Minerals / Q000378:metabolism; D018517:Plant Roots / Q000187:drug effects; D011188:Potassium / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000493:pharmacokinetics* / Q000633:toxicity*
chemical_list: D008903:Minerals; D000644:Quaternary Ammonium Compounds; D002734:Chlorophyll; D011188:Potassium