紫外辐射对浒苔游孢子附着、萌发和幼苗生长的影响  

The influence of UV radiation on the zoospores of the greentide macroalga (Ulva prolifera)

作　　者：李信书[1,2] 冯子慧[1] 霍元子[1] 徐军田[2] 何培民[1] 

机构地区：[1]上海海洋大学水产与生命学院,上海201306 [2]淮海工学院江苏省海洋生物技术重点实验室,江苏连云港222005

出　　处：《水产学报》2010年第12期1860-1868,共9页Journal of Fisheries of China

基　　金：国家海洋局绿潮专项;上海市科委浦江人才计划项目(05PJ14086);上海市水生生物学重点学科资助项目(S30701)

摘　　要：为了探讨绿潮藻浒苔游孢子对紫外线(UVR)的敏感性,研究了相对于有效光辐射(PAR,P)增加UVA辐射(PAR+UVA,PA)和全波长辐射(PAR+UVA+UVB,PAB)对浒苔游孢子的光合效率、附着、萌发和幼苗生长的影响。实验结果表明,(1)强光[900μmol/(m2·s)]下PA和PAB辐射对浒苔游孢子的最大光化学效率(Fv/Fm)具有明显抑制作用,且辐射时间越长抑制作用越大。强光下PA和PAB辐射15、30、60min导致浒苔游孢子最大光化学效率分别下降为28.4%、42.4%、36.5%、52.1%、64.4%、54.5%;(2)游孢子在15min辐射期间的附着率分别为50.0%(P)、44.9%(PA)和23.9%(PAB),紫外辐射尤其是UVB显著抑制(延迟)了游孢子的附着(P<0.05),但对24h后游孢子的总附着率没有显著影响。不同辐射处理和处理时间之间存在显著交互作用(P<0.05);(3)阳光下PA和PAB对孢子萌发具有显著抑制作用,第3天PA和PAB处理的游孢子萌发率分别为P处理的57.0%和39.1%,游孢子的萌发存活决定于最初的3d,3d后的紫外辐射对幼苗的存活没有显著影响(P>0.05);(4)阳光下PA和PAB对浒苔幼苗生长有显著抑制作用,第5天大于4细胞的幼苗比例分别为P:72.9%;PA:14.3%;PAB:10.1%。PA、PAB对游孢子苗面积生长的抑制率分别为46.2%和68.1%。可见UVR对浒苔游孢子的光合效率、附着时间、萌发和幼苗生长具有显著抑制作用,且PAB抑制作用比PA更强。以上结果显示,UVR影响浒苔的早期发育和存活,对浒苔种群的发生发展有重要影响。In order to assess the effects of UV radiation（UVR,280-400 nm） on the relative sensitivity,attachment,germination success and seedling growth of the zoospores of the green tide macroalga,Ulva prolifera,we exposed the cells to three different radiation treatments（PAB： 280-700 nm,PA： 320-700 nm,P： 400-700 nm） under solar or artificial radiation. The experimental units were covered with three different cut-off filters to obtain three treatments： PAB,PA and P under solar simulator,respectively. The light intensity was set at 900 μmol photons/（m2·s） ,while the irradiances of ultraviolet radiation were UV-A： 19. 9 W/m2,UV-B： 0. 68 W/m2,respectively. Optimum photosynthetic efficiency（Fv/Fm） of zoospores was measured as variable fluorescence of PSII by using a water pulse amplitude modulation（PAM） fluorometer. After being exposed to light treatments,the samples were then placed in the dark so that the zoospores could be attached to the cover glass slices randomly. After 24 h the settled zoospores were counted by microscope. The randomly settled zoospores on the cover glass slices were placed under different light treatments with cut-off filters. The germination success and growth were measured punctually. The results showed that： 1） PA and PAB treatments could significantly inhibit the zoospores optimum photosynthetic efficiency（Fv/Fm） under 900 μmol photons/（m2·s） ,and the extension of inhibition increased with exposure time. Moreover,the inhibition of PAB treatment was more obvious than those of P and PA treatments.（2） The hysteresis effects of zoospore settlement were observed under short-term ultraviolet radiation,and the results showed that 24 h settlement rate of PA and PAB treatments after short-term exposure to ultraviolet radiations of 5,10 and 15 min were not significant from control（P） .（3） The significant differences among the groups of germination success of settled zoospores were found when the samples were placed under different solar radiations.

关 键 词：浒苔 游孢子 紫外辐射 最大光化学效率 附着 萌发 幼苗生长 

分 类 号：S917.3[农业科学—水产科学] Q945.3[生物学—植物学]