In aquaculture,high-density seaweed farming brings higher economic benefits but also increases outbreaks of diatom felt.The effective control of diatom felt in high-density seaweed farming has always been a research h...In aquaculture,high-density seaweed farming brings higher economic benefits but also increases outbreaks of diatom felt.The effective control of diatom felt in high-density seaweed farming has always been a research hotspot.This study selected two potential allelochemicals 2-hydroxycinnamic acid and quinic acid to explore their effects on a diatom Nitzschia closterium and an economic seaweed Monostroma nitidum.The results showed that 2-hydroxycinnamic acid had better inhibitory effects than quinic acid on the growth,pigment content and photosynthetic efficiency of N.closterium.Their half-maximal inhibitory concentrations at 120 h(IC_(50–120 h))were 0.9000 and 1.278 mM,respectively.Additionally,these allelochemicals had limited inhibitory effects on the growth,pigment content and photosynthetic efficiency of M.nitidum before 24 h.To further explore the allelopathic effect of these chemicals,this study focused on the photosystem II energy fluxes of N.closterium.It was found that 3 mM 2-hydroxycinnamic acid could destroy the whole photosynthetic system by devastating the PSII reaction centre(RC)before 24 h;however,the same concentration of quinic acid could only down-regulate the electron transport efficiency by changing the effective antenna size of an active RC and downregulating the PSII reaction centre density.These experimental results are expected to provide a new strategy to control diatom felt blooms on the high-density seaweed farming areas.展开更多
Based on the observation and comparative analysis,overall and systematic development of M.latissimum in the stages from conjugation of gamete to discharge of zoospore,on the sporophyte stage during the life history of...Based on the observation and comparative analysis,overall and systematic development of M.latissimum in the stages from conjugation of gamete to discharge of zoospore,on the sporophyte stage during the life history of M.latissimum is entirely expatiated in this article.Meanwhile,on the basis of the results of the experiment,we divided the sporophyte stage of M.latissimum into five periods : conjugation of gametes(gamete 7.5 μm×2.0 μm),zygocyte(4-20 μm),sporange(18-40 μm),zoospore formation(sporange 35-55 μm) and discharge of zoospore(zoospore 9.4 μm×3 μm).In this paper it may be in China to find the systemic acknowledgement on the division of the sporange stage during the life history of Monostroma as well as to the seedling cultivation in practice.展开更多
The rbcL gene of Ulva pertusa,Enteromorpha prolifera and Monostroma grevillei was amplified,sequenced and analyzed.By comparing the rbcL sequences with seven other Ulvales species retrieved from GenBank,the sequence d...The rbcL gene of Ulva pertusa,Enteromorpha prolifera and Monostroma grevillei was amplified,sequenced and analyzed.By comparing the rbcL sequences with seven other Ulvales species retrieved from GenBank,the sequence divergences and thephyletic evolution were analyzed and the phylogenetic tree was constructed.From the phylogenetic tree,it can be found that U.per-tusa,E.prolifera and U.californica group in one branch,while E.compressa,U.rigida and U.fenestrata cluster in another clade.Obviously,unlike the Enteomorpha species,the Ulva species do not gather in one branch.Therefore Ulva and Enteomorpha might beaffiliates of one genus.E.compressa and E.intestinalis gathered together,which coincided with the morphological characters.However,the thallus of U.pertusa is thick and with many holes,which is different from E.prolifera in morphology.They cluster togetherin the phylogenetic tree with a genetic distance of 0.005.The results indicate that Ulva and Enteromorpha are not distinguishedstrictly.展开更多
基金sponsored by the Ph.D.Start-Up Foundation of Guangdong Ocean University(R19049)Science and Technology Planning Project of Guangdong(2017A030303078)Undergraduate Start-Up Foundation of Guangdong Ocean University(580520135 and 570119011).
文摘In aquaculture,high-density seaweed farming brings higher economic benefits but also increases outbreaks of diatom felt.The effective control of diatom felt in high-density seaweed farming has always been a research hotspot.This study selected two potential allelochemicals 2-hydroxycinnamic acid and quinic acid to explore their effects on a diatom Nitzschia closterium and an economic seaweed Monostroma nitidum.The results showed that 2-hydroxycinnamic acid had better inhibitory effects than quinic acid on the growth,pigment content and photosynthetic efficiency of N.closterium.Their half-maximal inhibitory concentrations at 120 h(IC_(50–120 h))were 0.9000 and 1.278 mM,respectively.Additionally,these allelochemicals had limited inhibitory effects on the growth,pigment content and photosynthetic efficiency of M.nitidum before 24 h.To further explore the allelopathic effect of these chemicals,this study focused on the photosystem II energy fluxes of N.closterium.It was found that 3 mM 2-hydroxycinnamic acid could destroy the whole photosynthetic system by devastating the PSII reaction centre(RC)before 24 h;however,the same concentration of quinic acid could only down-regulate the electron transport efficiency by changing the effective antenna size of an active RC and downregulating the PSII reaction centre density.These experimental results are expected to provide a new strategy to control diatom felt blooms on the high-density seaweed farming areas.
文摘Based on the observation and comparative analysis,overall and systematic development of M.latissimum in the stages from conjugation of gamete to discharge of zoospore,on the sporophyte stage during the life history of M.latissimum is entirely expatiated in this article.Meanwhile,on the basis of the results of the experiment,we divided the sporophyte stage of M.latissimum into five periods : conjugation of gametes(gamete 7.5 μm×2.0 μm),zygocyte(4-20 μm),sporange(18-40 μm),zoospore formation(sporange 35-55 μm) and discharge of zoospore(zoospore 9.4 μm×3 μm).In this paper it may be in China to find the systemic acknowledgement on the division of the sporange stage during the life history of Monostroma as well as to the seedling cultivation in practice.
基金supported by the National Natural Scientific Foundations of China(Grant No.30570125)the Key Construction Laboratory of Marine Biotechnology of Jiangsu Province(Grant No.2005HS006)
文摘The rbcL gene of Ulva pertusa,Enteromorpha prolifera and Monostroma grevillei was amplified,sequenced and analyzed.By comparing the rbcL sequences with seven other Ulvales species retrieved from GenBank,the sequence divergences and thephyletic evolution were analyzed and the phylogenetic tree was constructed.From the phylogenetic tree,it can be found that U.per-tusa,E.prolifera and U.californica group in one branch,while E.compressa,U.rigida and U.fenestrata cluster in another clade.Obviously,unlike the Enteomorpha species,the Ulva species do not gather in one branch.Therefore Ulva and Enteomorpha might beaffiliates of one genus.E.compressa and E.intestinalis gathered together,which coincided with the morphological characters.However,the thallus of U.pertusa is thick and with many holes,which is different from E.prolifera in morphology.They cluster togetherin the phylogenetic tree with a genetic distance of 0.005.The results indicate that Ulva and Enteromorpha are not distinguishedstrictly.
