黏管藻的分子鉴定与生长特性研究

对分布在辽宁大连黑石礁、付家庄、石槽、金石滩、獐子岛与海洋岛沿岸的黏管藻Gloiosiphonia capillaris (Hudson) Carmichael]的外部形态、营养与生殖结构、生物量、成熟个体比例与成熟个体生物量/总生物量(R/T指数)的变化、温度性质以及rbcL、COⅠ基因序列进行了详细研究。结果表明: (1) 黏管藻配子体为雌雄同体, 直立, 单生或丛生, 主轴明显, 固着器呈圆盘状, 质地胶质, 颜色为红色或紫红色。采集于獐子岛与海洋岛的藻体长度和宽度明显高于其他采集地点; (2) 藻体由皮层及髓部组成, 皮层由6—10层细胞组成, 髓部存在假根丝细胞。成熟囊果小, 突出于藻体表面, 呈球形或半球形, 通常2—4个囊果聚集在一起; (3) 黏管藻配子体的生物量在6月达到最大, 平均生物量为3.628 g/m2。3—6月成熟个体比例逐渐增大, 6月达到100%; (4) 黏管藻配子体生长周期为3—7月, 温度性质属于温带性; (5) rbcL基因序列分析表明, 6个采集地点的样本间无碱基差异, 与产自加拿大的黏管藻聚在一起, 形成一个独立的分支。COⅠ基因序列分析表明, 6个采集地点的样本间无碱基差异, 形成一个独立的分支, 均确定为黏管藻。

MOLECULAR CHARACTERISTICS AND GROWTH STATUS OF GLOIOSIPHONIA CAPILLARIS

This study analyzed the external morphology, vegetative and reproductive structure, growth process, biomass variation, mature individual proportion, R/T index, as well as the large subunit of ribulose-1, 5-bisphosphate carboxylase/oxygenase (rbcL) gene and the partial cytochrome coxidase Ⅰ (COⅠ) gene sequences of Gloiosiphonia capillaris (Hudson) Carmichael populations collected in the coast of Heishijiao, Fujiazhuang, Shicao, Jinshitan, Zhangzidao and Haiyangdao in Dalian. The results indicated that the gametophytes of G. capillaris were androgynous, solitary or caespitose habit, and that the main axes were erect, disciformi affixus, gelatinous in texture, red or purplish red. The length and width of thallus collected in Zhangzidao and Haiyangdao were significantly higher than those in other sites. Thallus was composed of cortex that had 6—10 cell layers and medulla that was consisted of many rhizoidal filaments. The size of mature cystocarp was small and protruded from the thallus. Cystocarps were spherical or hemispherical, and often became a group with 2—4 members. The maximum biomass of gametophyte appeared in June with an average value of 3.628 g/m2. The proportions of mature individuals increased gradually from March to June and got 100% in June. The gametophyte growth cycle was from March to July, and the temperature property was temperate. According to the phylogenetic tree of rbcL gene sequences, there was no sequence divergence among the 6 sites and clustered in a single monophyletic subclade with the sample from Canada. There was also no sequence divergence among the 6 sites based on the phylogenetic tree of COⅠ gene sequences. The samples were clustered in a single monophyletic subclade and identified as G. capillaris.