首页 | 本学科首页   官方微博 | 高级检索  
     


Interactive effects of salinity and irradiance on photoprotection in acclimated seedlings of two sympatric mangroves
Authors:Rochelle Christian
Affiliation:(1) Ecosystem Dynamics Group, Research School of Biological Sciences, Australian National University, Canberra, ACT, 0200, Australia
Abstract:The synergistic effects of irradiance and salinity on leaf angle, the photochemical efficiency of photosystem II and photosynthetic pigment composition of mangroves were studied in a factorial experiment. Seedlings of Aegiceras corniculatum (L.) Blanco (Myrsinaceae) and Avicennia marina (Forstk.) Vierh var. australasica (Walp.) Moldenke (Avicenniaceae) were grown under salinity treatments (0, 5, 25, 50, 75, and 100% artificial seawater), in full sunlight or under shade cloth (transmitting 30 or 70% sunlight), during summer and autumn. Significant speciesrsquo differences and effects of salinity and growth irradiance were found for key measures. Depressions in Fv/Fm due to salinity and growth irradiance were chronic, they were least in 25% seawater and in 30% sunlight, and greater in low and high salinity, and higher irradiance. A diurnal depression of Fv/Fm was superimposed on the chronic depression, and was greater for Ae. corniculatum than Av. marina. Increases in leaf angle; and increases in the size, and de-epoxidation state of the xanthophyll cycle pigment pool afforded protection from adverse effects of excess excitation energy. Adverse effects of the highest salinities on beta,beta-carotene and beta,epsiv-carotene biosynthetic pathways were suggested, particularly in Ae. corniculatum. The ecological significance of differences in speciesrsquo extent and temporal patterns of response are discussed.
Keywords:Carotenoids  Leaf angle  Light  Photoinhibition  Xanthophyll cycle
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号