盐度波动对2种热带海草光合生理与生长的影响  

Effects of salinity fluctuation on photosynthetic physiology and growth of two tropical seagrass species

作　　者：王茹 刘明中 吴佳欣 康银吉 WANG Ru;LIU Mingzhong;WU Jiaxin;KANG Yinji(Yazhou Bay Innovation Institute/Hainan Modern Marine Ranching Engineering Research Center,Hainan University of Tropical Ocean,Sanya,Hainan 572022,China)

机构地区：[1]海南热带海洋学院崖州湾创新研究院/海南省现代化海洋牧场工程研究中心,海南三亚572022

出　　处：《热带生物学报》2024年第4期471-481,共11页Journal of Tropical Biology

基　　金：海南省自然科学基金青年基金项目(322QN325);海南省自然科学基金青年基金项目(423QN250);2022年海南热带海洋学院州湾创新研究院青年项目(2022CXYQNXM03)。

摘　　要：为探讨生长于潮间带的不同种类海草对盐度波动适应阈值的高低与具体适应机制,将圆叶丝粉草(Cymodocea rotundata)和泰来草(Thalassia hemprichii)分别种植于盐度波动幅度从0到10逐步增大的海水环境中,探究其生理生长与光合特性的变化规律。结果表明:随盐度波幅逐渐增大,除泰来草的叶片生长速率、叶绿素a含量持续递增外,2种海草的平均叶面积、光合产物、光合色素以及圆叶丝粉草的叶片生长速率均呈先增大后减小的趋势;2种海草的F_(v)/F_(m)、F_(v)/F_(o)、qP和Y(II)呈现先增大后减小的趋势,而Y(NPQ)、Y(NO)和qN则先减小后增大的趋势。盐度波幅、海草种类及其交互作用对平均叶面积、叶片生长速率、淀粉、可溶性糖、可溶性蛋白、叶绿素a、叶绿素b、类胡萝卜素、F_(v)/F_(m)、F_(v)/F_(o)、qP、qN、Y(II)、Y(NPQ)、Y(NO)和最大电子传递速率(ETR_(max))这些指标有显著影响(P<0.05)。研究结果表明,盐度波幅为2~6和2~10的水环境分别能促进圆叶丝粉草和泰来草的光合作用与生长;圆叶丝粉草与泰来草具有最适盐度波动范围,超过该范围的盐度波动不利于2种海草的生理生长与光合作用,并且圆叶丝粉草比泰来草对盐度波动更敏感。Seagrasses that grow in the intertidal zone is adaptable to salinity fluctuations.However,considering that extreme weather and human activities may cause intensification of coastal seawater salinity fluctuation,the adaptation thresholds of seagrasses to the salinity fluctuation and the physiological mechanism are worth exploring.In this context an experiment was made with controllable salinity fluctuation amplitudes of seawater,and two seagrass species,Cymodocea rotundata and Thalassia hemprichii,were planted in the seawater with different salinity fluctuation amplitudes from 0 to 10.The changes of seagrass growth indicators related to photosynthesis were determined.The results showed that with the increase of salinity fluctuation amplitudes,average leaf area,photosynthetic products,photosynthetic pigments of the two seagrass and leaf growth rate of C.rotundata increased first and then decreased,except for the leaf growth rate and the content of Chl-a for T.hemprichii that increased continuously.F_(v)/F_(m),F_(v)/F_(o),qP and Y(II)of the two seagrass species increased first and then decreased,while Y(NPQ),Y(NO)and qN decreased first and then increased.Salinity fluctuation amplitudes,species and their interactions had significant influence on average leaf area,leaf growth rate,contents of starch,soluble sugar,soluble protein,Chl-a,Chl-b,carotenoids,F_(v)/F_(m),F_(v)/F_(o),qP,qN,Y(II),Y(NPQ),Y(NO)and maximum electron transport rate(ETR_(max))(P<0.05).These results showed that the water environment with salinity fluctuations of 2~6 and 2~10 could promote the photosynthesis and growth of C.rotundata and T.hemprichii,respectively.These ranges of salinity fluctuation are optimum for both the two seagrass species,while other ranges of salinity fluctuation was not conducive to the physiological growth and photosynthesis of the two seagrass species.

关 键 词：圆叶丝粉草 泰来草 盐度波动 光合作用 生长 

分 类 号：Q945.79[生物学—植物学]