title: [Allelopathic influence of Myriophyllum spicatum on the photosynthetic efficiency of Microcystis aeruginosa].
abstract: The allelopathic influence of Myriophyllum spicatum on chlorophyll content and chlorophyll fluorescence parameters of Microcystis aeruginosa was studied in coexistence condition. Chlorophyll fluorescence parameters included q(N) (non-photochemical quenching), Y II (effective quantum yield), F(v)/F(m) (maximum quantum yield), F'(v)/F'(m) (effective quantum yield of photosystem II photochemistry) and ETR (electron transport rate). During the three days under coexistence condition, chlorophyll content and chlorophyll fluorescence parameters of M. aeruginosa were affected by M. spicatum and presented different sensitivities. Chlorophyll content of M. aeruginosa was significantly inhibited by 20.80% on the second day at 10.0 g/L of M. spicatum (P < 0.05). However, chlorophyll fluorescence parameters of M. aeruginosa decreased earlier and rapider than chlorophyll content. On the first day, q(N) and Y II of M. aeruginosa were significantly inhibited by 15.59% and 13.00% at 5.0 g/L of M. spicatum (P < 0.05), and F(v)/F(m) and F'(v) /F'(m) were declined by 15.87% and 12.07% at 10.0 g/L (P < 0.05), respectively. On the third day, ETR and three parameters based on ETR were affected at all levels of M. spicatum (P < 0.05). The inhibition effects on the photosynthetic activity of M. aeruginosa might be considered as one of the target sites of M. spicatum and chlorophyll fluorescence parameters were more sensitive parameters than chlorophyll content, especially q(n).
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
authors.forename: Jun-Ying
authors.initials: JY
authors.lastname: Zhu
authors.forename: Bi-Yun
authors.initials: BY
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Yun-Ni
authors.initials: YN
authors.lastname: Gao
authors.forename: Fang-Jie
authors.initials: FJ
authors.lastname: Ge
authors.forename: Wei
authors.initials: W
authors.lastname: Liang
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Zhang
authors.forename: Zhen-Bin
authors.initials: ZB
authors.lastname: Wu
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D005453:Fluorescence; D019684:Magnoliopsida / Q000378:metabolism / Q000502:physiology*; D046931:Microcystis / Q000187:drug effects*; D010675:Pheromones / Q000096:biosynthesis / Q000494:pharmacology*; D010788:Photosynthesis / Q000187:drug effects*; D045332:Photosystem II Protein Complex / Q000187:drug effects / Q000502:physiology
chemical_list: D010675:Pheromones; D045332:Photosystem II Protein Complex; D002734:Chlorophyll