作　　者： ; (刘洪）; (赵建刚）; (叶长鹏）;

机构地区： 暨南大学

出　　处： 《水生生物学报》 2022年第2期168-175,共8页

摘　　要： 为了探究大型海藻裂片石莼(Ulva fasciata)防治赤潮的可行性,研究将赤潮异弯藻(Heterosigma akashiwo)分别暴露在浓度为0.6、1.2、2.4和4.8 g/L的裂片石莼藻粉中,观察赤潮异弯藻光合系统的响应。实验用植物效率分析法测定了赤潮异弯藻的光合效率,用透射电子显微镜法观察了赤潮异弯藻叶绿体等的结构变化,从光合色素、光合效率和细胞微观结构等角度,阐释了大型海藻裂片石莼藻粉对赤潮异弯藻的生物防治机理。实验结果表明,裂片石莼藻粉能够显著降低赤潮异弯藻光合色素,抑制其生长。在72h时,0.6、1.2、2.4和4.8 g/L石莼藻粉处理组对赤潮异弯藻抑制率分别为19.6%、46.5%、71.4%和79.4%;叶绿素快速荧光动力学结果表明,在实验72h时,裂片石莼藻粉能够显著降低赤潮异弯藻的光合效率、降低叶绿素快速荧光曲线,并呈现出一定的剂量效应。在4.8 g/L处理组中,赤潮异弯藻单位反应中心吸收的能量ABS/RC和用于还原Q_(A)的能量TR_(o)/RC分别上升至对照组的15倍和1.5倍,而单位反应中心电子传递的能量ET_(o)/RC、最大光化学效率ψP_(o)、电子传递的量子产额ψE_(o)、电子超过Q_(A)比例Ψ_(o)分别下降81.3%、81.2%、91.7%和81.7%,说明裂片石莼藻粉抑制了光合反应中心及其电子供侧体的性能,并阻断了电子传递。透射电子显微镜观察发现,赤潮异弯藻在4.8 g/L裂片石莼藻粉处理72h后,其类囊体片层断裂、排列混乱,类囊体膜融合,叶绿体外膜破裂,同时线粒体、细胞核和细胞膜结构也遭到破坏。综上,裂片石莼藻粉对赤潮异弯藻的光合系统产生了明显破坏作用,抑制了赤潮异弯藻的正常生长。因此,大型海藻裂片石莼是一种潜在的防治以赤潮异弯藻为优势种所引发赤潮的“工具藻”,并可以对其生物防治赤潮实际应用做更深入的研究。 Heterosigma akashiwo is a typical red tide alga.To elucidate mechanisms of harmful algal blooms(HABs)by Ulva fasciata,H.akashiwo was exposed to gradient concentrations of 0.6,1.2,2.4 and 4.8 g/L dried U.fasciata powder,and then measured the photosynthetic efficiency of H.akashiwo by plant efficiency analysis(PEA)and its ultrastructure via transmission electron microscope(TEM).The results showed that dried U.fasciata powder significantly reduced the content of photosynthetic pigments in H.akashiwo and inhibited its growth.At 72 hours,the inhibition rates of treatments from low to high concentration were 19.6%,46.5%,71.4%,and 79.4%,respectively.Dried U.fasciata powder significantly reduced the photosynthetic efficiency of H.akashiwo and reduced its OJIP curve at 72 hours with a dose-dependent pattern.Compared to control group,4.8 g/L treatment group increased the energy absorbed into per photosynthetic reaction center(ABS/RC)in H.akashiwo and the energy used for deoxygenate Q_(A)(TR_(o)/RC)15 times and 1.5 times,respectively.Simultaneously,4.8 g/L treatment group reduced the energy consumed for electron transmission in per reaction center(ET_(o)/RC),the maximum photochemical efficiency(ψP_(o)),the quantum yield of electron transfer(ψE_(o)),and the ratio of electrons exceeding Q_(A)(Ψ_(o))by 81.3%,81.2%,91.7%and 81.7%,respectively.Treated with 4.8 g/L dried U.fasciata powder for 72 hours,the thylakoid lamellas of H.akashiwo were broken and arranged disorderly,thylakoid membranes were fused,chloroplast outer membranes were ruptured,mitochondria and cell nuclei were ruptured,and cell membrane structure was destroyed.This result indicated that dried U.fasciata powder inhibited the photosynthetic reaction center and electron donor function,and the transmission of electrons was blocked.Observation through TEM showed that after 72h treatment with 4.8 g/L dried U.fasciata powder,the thylakoid lamellas of H.akashiwo were broken,arranged disorderly,thylakoid membranes were fused,chloroplast outer membranes were ruptured,m

关 键 词： 大型海藻 裂片石莼 赤潮异弯藻 叶绿素荧光动力学 超微结构

领　　域： [生物学—植物学]