Morphology and phylogeny of small armored dinoflagellate Azadinium species isolated from Japanese and Vietnamese coasts were examined by light microscopy, scanning electron microscopy and molecular phylogeny inferred from ITS and LSU rDNA (D1–D3) sequences. Dominant azaspiracids (AZAs) were analyzed by using liquid chromatography/triple quadrupole mass spectrometer (LC/MS/MS). Sixteen and four culture strains were established from Japan and Vietnam, respectively. A phylogenetic tree confirmed our species identifications of Japanese cultures as Azadinium poporum (ribotypes A, B and C), A. trinitatum and A. zhuanum, and Vietnamese cultures as A. poporum (ribotype B). Typical cells of A. poporum had the thecal tabulation of Po, cp, X, 4′, 3a, 6″, 6C, 5S, 6″′, 2″″, A. trinitatum had Po, cp, X, 4–5′, 3a, 6–7″, 6C, 5S, 5–6″′, 2″″ and A. zhuanum had Po, cp, X, 3–4′, 2a, 6″, 6C, 5S, 6″′, 2″″. Cellular morphology of the three species were congruent with those in the original reports, in terms of the presence/absence of antapical spine and the position of the ventral pore, nucleus and pyrenoids, although small differences were also found in the nucleus position of A. trinitatum and A. zhuanum. AZA-2 was the dominant component in Japanese A. poporum (ribotypes A, B and C), and AZA-40 in Vietnamese A. poporum (ribotype B). AZA-2 and AZA-40 were not detected in Vietnamese and Japanese A. poporum, respectively. AZA analogs were not detected from A. trinitatum and A. zhuanum. This is the first report of the toxigenic A. poporum from Japan and Vietnam, with identifications of the major AZAs. The ribotype A of A. poporum and A. trinitatum were the first records in Asia.

中文翻译：

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来自日本和越南的 Azadinium poporum（Amphidomataceae，Dinophyceae）的产毒菌株，在亚太地区首次报道了 A. poporum（核糖型 A）和 A. trinitatum

通过光学显微镜、扫描电子显微镜和从 ITS 和 LSU rDNA (D1-D3) 序列推断的分子系统发育，检查了从日本和越南海岸分离的小型装甲甲藻Azadinium物种的形态学和系统发育。通过使用液相色谱/三重四极杆质谱仪 (LC/MS/MS) 分析主要的氮杂螺酸 (AZA)。分别从日本和越南建立了 16 个和 4 个培养菌株。系统发育树证实了我们将日本文化的物种鉴定为Azadinium poporum（核糖型A、B 和 C）、A. trinitatum和A. zhuanum，以及越南文化为A. poporum（核糖型B）。A. poporum的典型细胞有 Po, cp, X, 4', 3a, 6", 6C, 5S, 6"', 2"" 的表列，A. trinitatum有 Po, cp, X, 4-5', 3a, 6- 7", 6C, 5S, 5-6"', 2"" 和A. zhuanum有 Po, cp, X, 3-4', 2a, 6", 6C, 5S, 6"', 2""。这三个物种的细胞形态与原始报告中的一致，在有/无背刺以及腹孔、细胞核和蛋白核的位置方面，尽管在A.的细胞核位置也发现了小的差异。 trinitatum和A. zhuanum。AZA-2 是日本A. poporum（核糖型A、B 和 C）中的主要成分，而 AZA-40 是越南A. poporum 中的主要成分（核糖型 B）。AZA-2 和 AZA-40 分别在越南和日本A. poporum中未检测到。从A. trinitatum和A. zhuanum中未检测到 AZA 类似物。这是日本和越南产毒A. poporum的第一份报告，并确定了主要的 AZA。的核糖型一A. poporum和A. trinitatum是亚洲第一的记录。