title: The response of the early developmental stages of Laminaria japonica to enhanced ultraviolet-B radiation.
abstract: The responses of the early development of Laminaria japonica collected from Kiaochow Bay in China to enhanced ultraviolet-B radiation (UV-B, 280-320 nm) were studied in the laboratory. The low UV-B radiations (11.7-23.4 J x m(-2) x d(-1)) had no significant effects on zoospores attachment, but when the UV-B dose > 35.1 J x m(-2) x d(-1) the attachment decreased significantly compared with the control. Germination of embryospores was >93% under the low (11.7-35.1 J x m(-2) x d(-1)) doses, and in the range of 78.5%-88.5% under the high (46.8-70.2 J x m(-2) x d(-1)) UV-B doses, indicating a significant radiation effect. Under the higher UV-B exposure (35.1-70.2 J x m(-2) x d(-1)), all of the few gametophytes formed from embryospores died 120 h post-release. After exposure to the low UV-B radiation (11.7-23.4 J x m(-2) x d(-1)), the formation of sporophytes decreased and the female gametophyte clones increased compared with the control. However, the sex ratio and the relative growth of female gametophytes/sporophytes had not significantly changed. According to the results, enhanced UV-B radiation has a significant effect on the early development of L. japonica under laboratory conditions, suggesting that the UV-B radiation could not be overlooked as one of the important environmental factors influencing the ontogeny of macroalgae living in marine ecosystems.
authors.affiliation: Laboratory of Ecology, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
authors.forename: Su
authors.initials: S
authors.lastname: Liu
authors.forename: QuanSheng
authors.initials: Q
authors.lastname: Zhang
authors.forename: You
authors.initials: Y
authors.lastname: Wang
authors.forename: Qing
authors.initials: Q
authors.lastname: Ju
authors.forename: XueXi
authors.initials: X
authors.lastname: Tang
mesh_terms: D004307:Dose-Response Relationship, Radiation; D007795:Laminaria / Q000502:physiology / Q000528:radiation effects; D014466:Ultraviolet Rays