Invasive macroalgae are recognized as one of the greatest threats to local marine ecology and economy.Chaetomorpha valida is an invasive species in China,originally found in Dalian City,Liaoning Province,and has now i...Invasive macroalgae are recognized as one of the greatest threats to local marine ecology and economy.Chaetomorpha valida is an invasive species in China,originally found in Dalian City,Liaoning Province,and has now invaded southward to seas such as Rongcheng City,Shandong Province.Its overgrowth has seriously damaged the local mariculture industry.Based on two strains of C.valida isolated in our previous study,this study explores the effects of temperature and irradiance on their growth and reproduction under laboratory conditions.The results show that the suitable temperature ranges are primarily 21−29℃.The optimal temperature is 25℃for gametophytic growth and sporophytic asexual reproduction,and 29℃for sporophytic growth and gametophytic sexual reproduction.And there is no significant effect of irradiance on their growth and reproduction.Meanwhile,the suitable temperature ranges and optimum irradiance for the growth and reproduction of both strains are largely similar,with only slight differences in the suitable ones for sporophytic asexual reproduction and gametophytic growth.Accordingly,the effect of temperature on the isomorphic generation alternation in C.valida was analyzed,as well as the dynamics of its generation alternation and invasive potential for its environmental adaptation in the northern and southern seas of China.This will help to understand its dynamic pattern spreading from the north to south in China,and also be an important reference for understanding the generation alternation characteristics,invasions and prevention of the outbreaks of other green tidal algae.展开更多
The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphologica...The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphological characters of C. valida. Results reveal that gametophytic filaments often produce lateral branches under laboratory culture conditions, suggesting an atypical heteromorphic life cycle of C. valida between unbranched sporophytes and branched gametophytes, which differs from typical isomorphic alternation of Chaetomorpha species. The shape of the basal attachment cell, an important taxonomic character within the genus, was found variable depending on environmental conditions. The 18S rDNA and 28S rDNA regions were used to explore the phylogenetic affinity of the taxa. Inferred trees from 18S rDNA sequences revealed a close relationship between C. valida and Chaetomorpha moniligera. These results would enrich information in general biology and morphological plasticity of C. valida and provided a basis for future identification of green tide forming algae.展开更多
The marine green algae genus Chaetomorpha is a common source of“green tide”and is widespread on coasts around the world.In this study,based on invasive Chaetomorpha valida collected from the Shandong Peninsula,the m...The marine green algae genus Chaetomorpha is a common source of“green tide”and is widespread on coasts around the world.In this study,based on invasive Chaetomorpha valida collected from the Shandong Peninsula,the morphogenesis and reproductive characteristics of two strains that are morphologically different from each other,were observed using experimental biology methods.The main results are as follows:(1)significant difference in the size of reproductive cells produced by Strains 1 and 2;(2)gametes produced by Strain 2 are isogamous and same gametangial during the binding process of gametes,whereas those of Strain 1 are isogamous but hetero-cystic;(3)progeny from Strain 1 has rhizoidal holdfast,whereas that of Strain 2 has discoid holdfast;(4)gametophytic“branching”was found in Strain 1.These results could validate the high phenotypic plasticity of macroalgae and offered an interpretation of habitat adaptation.Furthermore,this study innovatively provided fundamental research on the selection of macroalgal traits and explored competitive strategies for the dominant survival of macroalgae from a new perspective.展开更多
在实验室培养条件下,以采自辽宁大连的强壮硬毛藻为试验对象,对其在不同盐度和透明度条件下的生长发育情况进行研究。设置10、20、30、40、50 5个盐度组,设置40、60、80、120、140 cm 5个透明度组,试验采用单因素方差分析,只改变其中一...在实验室培养条件下,以采自辽宁大连的强壮硬毛藻为试验对象,对其在不同盐度和透明度条件下的生长发育情况进行研究。设置10、20、30、40、50 5个盐度组,设置40、60、80、120、140 cm 5个透明度组,试验采用单因素方差分析,只改变其中一个环境因子,其余环境因子不变,对强壮硬毛藻进行分组培养,然后对其日特定生长率进行测定与分析。试验结果显示,盐度和透明度对强壮硬毛藻的生长发育均有一定影响。藻体生长的适宜盐度为30~40,其中在盐度为30时,藻体的日特定生长速率最高,达65%,随盐度的继续升高,强壮硬毛藻的日特定生长率呈下降趋势,在盐度达到50时,藻体出现死亡现象;在透明度高于120 cm时,藻体生长状况良好,透明度低于120 cm时,藻体的生长由于水下光照条件的限制而受到了明显的抑制。本试验表明,强壮硬毛藻为广盐性种,且高盐、低透明度条件对强壮硬毛藻的生长发育有一定抑制作用,为强壮硬毛藻的防治提供了一定理论依据。展开更多
基金The National Natural Science Foundation of China under contract Nos 32270219 and 31970216.
文摘Invasive macroalgae are recognized as one of the greatest threats to local marine ecology and economy.Chaetomorpha valida is an invasive species in China,originally found in Dalian City,Liaoning Province,and has now invaded southward to seas such as Rongcheng City,Shandong Province.Its overgrowth has seriously damaged the local mariculture industry.Based on two strains of C.valida isolated in our previous study,this study explores the effects of temperature and irradiance on their growth and reproduction under laboratory conditions.The results show that the suitable temperature ranges are primarily 21−29℃.The optimal temperature is 25℃for gametophytic growth and sporophytic asexual reproduction,and 29℃for sporophytic growth and gametophytic sexual reproduction.And there is no significant effect of irradiance on their growth and reproduction.Meanwhile,the suitable temperature ranges and optimum irradiance for the growth and reproduction of both strains are largely similar,with only slight differences in the suitable ones for sporophytic asexual reproduction and gametophytic growth.Accordingly,the effect of temperature on the isomorphic generation alternation in C.valida was analyzed,as well as the dynamics of its generation alternation and invasive potential for its environmental adaptation in the northern and southern seas of China.This will help to understand its dynamic pattern spreading from the north to south in China,and also be an important reference for understanding the generation alternation characteristics,invasions and prevention of the outbreaks of other green tidal algae.
基金Supported by General and Major Projects of the National Natural Science Foundation of China(Nos.31070185,31093440)the Science and Technology Project of Guangdong Province(Nos.2011B031100010,2012A020200007)+3 种基金the Talent Introduction Projects of Guangdong Province Universities and Collegesthe Team Project of Natural Science Foundation of Guangdong Province(No.S2011030005257)the Grant of the Key Laboratory of Integrated Marine Monitoring and Applied Technologies for Harmful Algal Blooms,SOA(MATHAB)(No.MATHAB20100301)the Science and Technology Project of Shantou City,China(No.2011-162)
文摘The marine green alga Chaetomorpha valida fouls aquaculture ponds along the coastal cities of Dalian and Rongcheng, China. Unialgal cultures were observed under a microscope to determine the developmental morphological characters of C. valida. Results reveal that gametophytic filaments often produce lateral branches under laboratory culture conditions, suggesting an atypical heteromorphic life cycle of C. valida between unbranched sporophytes and branched gametophytes, which differs from typical isomorphic alternation of Chaetomorpha species. The shape of the basal attachment cell, an important taxonomic character within the genus, was found variable depending on environmental conditions. The 18S rDNA and 28S rDNA regions were used to explore the phylogenetic affinity of the taxa. Inferred trees from 18S rDNA sequences revealed a close relationship between C. valida and Chaetomorpha moniligera. These results would enrich information in general biology and morphological plasticity of C. valida and provided a basis for future identification of green tide forming algae.
基金Supported by the National Natural Science Foundation of China(Nos.32270219,31970216)。
文摘The marine green algae genus Chaetomorpha is a common source of“green tide”and is widespread on coasts around the world.In this study,based on invasive Chaetomorpha valida collected from the Shandong Peninsula,the morphogenesis and reproductive characteristics of two strains that are morphologically different from each other,were observed using experimental biology methods.The main results are as follows:(1)significant difference in the size of reproductive cells produced by Strains 1 and 2;(2)gametes produced by Strain 2 are isogamous and same gametangial during the binding process of gametes,whereas those of Strain 1 are isogamous but hetero-cystic;(3)progeny from Strain 1 has rhizoidal holdfast,whereas that of Strain 2 has discoid holdfast;(4)gametophytic“branching”was found in Strain 1.These results could validate the high phenotypic plasticity of macroalgae and offered an interpretation of habitat adaptation.Furthermore,this study innovatively provided fundamental research on the selection of macroalgal traits and explored competitive strategies for the dominant survival of macroalgae from a new perspective.
