硇洲岛半叶马尾藻中国变种的受精过程观察及其幼孢子体生长条件初探  

Observation of the fertilization process of Sargassum hemiphyllum var.chinense J.Agardhon Naozhou Island and a preliminary study on the optimal growth conditions for the juvenile sporophyte

作　　者：杨文成 谢恩义[1] 林坤 郭优优 王慧慧 陈春丽 辛榕 崔建军 YANG Wencheng;XIE Enyi;LIN Kun;GUO Youyou;WANG Huihui;CHEN Chunli;XIN Rong;CUI Jianjun(Fisheries College of Guangdong Ocean University,Zhanjiang 524088,China)

机构地区：[1]广东海洋大学水产学院,广东湛江524088

出　　处：《热带海洋学报》2025年第2期137-146,共10页Journal of Tropical Oceanography

基　　金：国家重点研发计划重点专项(2022YFD2401303);宁波市2023重大科技攻关暨揭榜挂帅项目(2023Z118)。

摘　　要：半叶马尾藻中国变种(Sargassum hemiphyllum var.chinese J.Agardh)是广泛分布于南海沿岸的大型经济海藻。为探究其有性生殖特点和人工育苗的可行性,文章对硇洲岛采集的半叶马尾藻中国变种藻的体外观、雌雄生殖托和生殖细胞的形态特征、受精卵的早期发育过程进行了观察。半叶马尾藻中国变种成熟藻体呈黄褐色,株高0.8~1m,雌雄异株。雌性生殖托呈黄褐色、圆柱形,表面长有较多的棘突,直径为(0.46±0.05)mm,长度为(2.50±0.67)mm;雄性生殖托颜色较浅、呈棒状,直径为(1.01±0.18)mm,长度为(9.21±2.36)mm。雌性生殖托释放的卵细胞属8核1卵型,椭球形或卵圆形,直径(76.32±10.11)μm,排卵后附挂于雌性生殖托上等待受精;雄生殖托释放的精子呈梨形,长度为(27.52±5.43)μm,具有鞭毛。受精后大部分受精卵会从生殖托脱落,固着于附着基上并开始早期发育。受精卵于第6小时开始第一次横分裂,随后经过数次横纵分裂,于第24小时发育成“地雷状”幼孢子体,28d后出现原生叶。文章还对适宜半叶马尾藻中国变种幼孢子体萌发的附着基质及适宜生长温度进行了探索。室内悬浮培养试验证明,25℃条件下幼孢子苗的存活率为90%,藻体生长速率为90.1μm·d^(-1)。Sargassum hemiphyllum var.chinense J.Agardh is an economic seaweed widely distributed along the coast of the South China Sea.To investigate the sexual reproductive characteristics and the feasibility of artificial seedling propagation of this brown macroalga,this study employed optical microscopy to examine the morphological features of the thallus,male and female receptacles,and the early developmental stages of fertilized eggs in S.hemiphyllum var.chinense from Naozhou Island.The results revealed that the mature thallus of this Chinese variant exhibited a yellow-brown hue with a height of 0.8 to 1 m.It exhibited dioecious traits and possessed discoid holdfasts composed of repetitive bifurcations.The female receptacles were yellow-brown and cylindrical,adorned with numerous surface spines,measuring(0.46 ± 0.05) mm in diameter and(2.50 ± 0.67) mm in length.Conversely,the male receptacles were lighter in color,adopting a rod-like morphology,with a diameter of(1.01 ± 0.18) mm and a length of(9.21 ± 2.36) mm.Eggs released from the female structures exhibited an eight-nucleate one-egg configuration,either ellipsoidal or oval,with an outside diameter of(76.32 ± 10.11) μm.Following ovulation,these eggs adhered to the female structures awaiting fertilization.Sperms released from the male structures were pear-shaped,measuring(27.52 ± 5.43) μm in length and equipped with flagella.At the post-fertilization stage,the majority of fertilized eggs detached from the receptacles,affixing to substrates and undergoing early developmental processes.Within six hours,these fertilized eggs underwent their initial transverse division,subsequently progressing through multiple transverse and longitudinal divisions,and ultimately culminating in the development of landmine-shaped sporophytes within 24 hours,with primary fronds emerging after 28 days.Additionally,this study investigated the indoor use of suitable artificial substrates for the germination of sporophytes and the effect of temperature on the S.hemiphyllum var.chinense

关 键 词：半叶马尾藻中国变种 有性生殖 生长 形态特征 

分 类 号：P735.531[天文地球—海洋生物学]