摘要
采用叶绿素荧光技术考察了不同潮汐模式下海萝藻体光合活性的日变化、海萝光合活性与藻体含水量之间的关系以及干露和光照对光合活性的交互影响.结果表明:早、中、晚潮汐相比,中午潮时最大量子产量(Fv/Fm)下降速度最快.早潮干露初期Fv/Fm下降较慢,随后加快;晚潮干露时Fv/Fm始终较快下降.各种潮汐模式下,Fv/Fm当日基本恢复至初始水平,呈现了可逆的下降,即动态光抑制.Fv/Fm及有效量子产量(ΦPSⅡ)随含水量的降低而下降,当含水量低于90%时,Fv/Fm和ΦPSⅡ下降迅速,但含水量6%左右的藻体重新浸没后仍能恢复光合作用,即通常情况下可以耐受72 h的干露,具有很强的干露耐受能力.藻体含水量(TWC)与Fv/Fm及ΦPSⅡ的函数关系为:Fv/Fm=0.68+(0.0044-0.68)/[1+(TWC/66.96)5],R2=0.99;ΦPSⅡ=0.585+(0.004-0.585)/[1+(TWC/73)10],R2=0.99.方差分析结果进一步显示,光强和干露交互作用对藻体光合活性影响显著,随光照增强和干露时间延长光抑制程度增大,强光(1000μmol pho·m-2·s-1)和长时间干露(6 h)叠加时,藻体光合活性降低程度最大,完全恢复所需时间最长.
In this study, the diurnal change of photosynthesis activity in response to various tidal patterns, the relationship between photosynthetic activity and tissue water content, and the interactive effect of desiccation and irradiance on photosynthetic activity in Gloiopeltis furcata were investigated by using portable pulse amplitude modulated （PAM） fluorometer. Results showed that Fv/Fm decreased more rapidly during the noon low tide than during the morningor evening low tide. Fv/Fm decreased slowly at the beginning of desiccation during the morning low tide, but decreased rapidly throughout the evening low tide. Fv/Fm recovered to the initial values on the same day no matter when the low tide occurred, suggesting the occurrence of dynamic photoinhibition. These features endowed G. furcata with an ability to adapt to the periodic desiccation on high intertidal rocks. The maximum （Fv/Fm） and effective （ΦPSII） quantum yield declined with the decrease of tissue water content （TWC）. However, photosynthetic activity could recover completely when TWC exceeded 6% , showing a strong ability of G. furcata to tolerate desiccation. The relationships between TWC and Fv/Fm and ΦPSII were as follows： Fv/Fm = 0.68 ＋ （0. 0044-0.68 ）/[ 1 ＋ （ TWC/ 66.96） 5 ], R2 =0.99 ; ΦPSII =0. 585＋（0. 004-0. 585 ）/[ 1 ＋（ TWC/73 ） 10 ], R2 = 0.99. ANOVA result further showed that the interactive effect of irradiance and desiccation on photosynthetic activity was significant, and that the photoinhibition degree increased with elevation of irradiation and duration of desiccation. The extreme condition （6 h desiccation at 1000 μmol photons·m-2 · s-1 ） resuited in a serious photoinhibition, with the longest period of complete recovery for photosynthesis activity.
出处
《应用生态学报》
CAS
CSCD
北大核心
2014年第5期1491-1498,共8页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(31070376)资助
关键词
海萝
光合作用
叶绿素荧光
干露
光照
Gloiopeltis furcata
photosynthesis
chlorophyll fluorescence
desiccation
irradiance.
