Interactions between Scrippsiella acuminata and three diatoms, Chaetoceros curvisetus, Phaeodactylum tricornutum, and Skeletonema dohrnii, were investigated using bi-algal co-cultures and cell-free and sonicated-cell filtrates in this study. Volatile aldehydes in sonicated filtrates of the three diatoms were analyzed by GC/MS. Furthermore, effects of 2E, 4E-decadienal (2,4-D) on the growth and the photosynthetic efficiency of the four microalgal species were studied. The growth of Sc. acuminata was significantly inhibited by the three diatoms in all co-cultures, and the inhibitory effects were higher under nutrient-rich conditions. Both cell-free and sonicated-cell filtrates of the three diatoms showed significant inhibitions on the growth of Sc. acuminata, which highlighted that diatoms produce allelopathic compounds not only to the surrounding environments but also inside the cells. Fifteen aldehydes were detected in the sonicated-cell filtrates of the three diatoms, and 5, 5, and 12 types of aldehydes were detected in C. curvisetus, P. tricornutum, and Sk. dohrnii, respectively. Polyunsaturated aldehydes (PUAs) composition differed among the three diatom species. Phenylglyoxal (C₈H₆O₂) dominated in C. curvisetus, 2,4-D (C₁₀H₁₆O) predominated in P. tricornutum, and high proportions of 2-hexenal (C₆H₁₀O), 2E, 4E-heptadienal (C₇H₁₀O), and 2,4-D were detected in Sk. dohrnii. 2,4-D showed significantly inhibitory effects on the growth of algal cells including diatoms themselves in a dose-dependent manner, and photosynthetic efficiency was significantly decreased as well. Sc. acuminata was the most sensitive species. The 96 h EC₅₀ values of 2,4-D on the growth of the four microalgae were 1.64 μmol/L for Sc. acuminata, 3.09 μmol/L for C. curvisetus, 4.93 μmol/L for P. tricornutum, and 8.54 μmol/L for Sk. dohrnii, respectively. The results suggest that PUAs produced by diatoms may help them to take the competitive advantages in phytoplankton community, and thus to sustain diatom-dominated community structure in nutrient rich coastal waters.

在本研究中，使用双藻共培养物和无细胞和超声细胞滤液研究了尖头尖顶角藻和三种硅藻、角角角藻、三角褐指藻和Skeletonema dohrnii之间的相互作用。通过 GC/MS 分析了三种硅藻的超声处理滤液中的挥发性醛。此外，还研究了 2E、4E-癸二烯醛 (2,4-D) 对四种微藻的生长和光合效率的影响。Sc的成长 尖尖的三种硅藻在所有共培养物中均受到显着抑制，且在营养丰富的条件下抑制作用更高。三种硅藻的无细胞和超声细胞滤液均显示出对Sc生长的显着抑制。acuminata，强调硅藻不仅对周围环境产生化感化合物，而且在细胞内部产生化感化合物。在三种硅藻的超声细胞滤液中检测到 15 种醛，在C. curvisetus、P. tricornutum和Sk中检测到5、5和 12 种醛。dohrnii，分别。三种硅藻中的多不饱和醛 (PUA) 组成不同。苯乙二醛 (C ₈ H ₆ O₂ ) 在C. curvisetus 中占主导地位， 2,4-D (C ₁₀ H ₁₆ O) 在P. tricornutum 中占优势，2-己烯醛 (C ₆ H ₁₀ O)、2E、4E-庚二烯醛 (C ₇ H ) 的比例很高₁₀ O) 和 2,4-D 在Sk中检测到。dohrnii。2,4-D以剂量依赖性方式对包括硅藻在内的藻类细胞的生长显示出显着的抑制作用，并且光合效率也显着降低。理学士 acuminata是最敏感的物种。2,4-D 对四种微藻生长的 96 h EC ₅₀值为 1.64 μmol/L理学士 acuminata，C. curvisetus为 3.09 μmol/L，P. tricornutum为 4.93 μmol/L，Sk为 8.54 μmol/L 。dohrnii，分别。结果表明，硅藻产生的 PUA 可能有助于它们在浮游植物群落中占据竞争优势，从而在营养丰富的沿海水域维持以硅藻为主的群落结构。